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  • 101.
    Makhalov, Petr B.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Semiconductor-Metal-Grating Slow Wave Amplifier for Sub-THz Frequency Range2019In: IEEE Transactions on Electron Devices, ISSN 0018-9383, E-ISSN 1557-9646, Vol. 66, no 10, p. 4413-4418Article in journal (Refereed)
    Abstract [en]

    The concept of semiconductor slow wave amplifier aimed at sub-terahetz frequencies is studied numerically. The scheme of the transversal amplifier with metal grating is proposed. The requirements on semiconductor parameters that provide positive net amplification are given and discussed, and the choice of GaN is explained. For the proposed device, different regimes are studied, and the dependence of the net amplification on device parameters is given. One regime has high linear gain, more than 50 dB/mm. The proof-of-principle structure for the excitation of the device in this regime is proposed and simulated.

  • 102.
    Maoz, Ben M.
    et al.
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Tel Aviv Univ, Dept Biomed Engn, Fac Engn, Tel Aviv, Israel.;Tel Aviv Univ, Sagol Sch Neurosci, Tel Aviv, Israel.;Tel Aviv Univ, Ctr Nanosci & Nanotechnol, Tel Aviv, Israel..
    Herland, Anna
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, Stockholm, Sweden..
    FitzGerald, Edward A.
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Grevesse, Thomas
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Vidoudez, Charles
    Harvard Univ, Small Mol Mass Spectrometry Facil, Cambridge, MA 02138 USA..
    Pacheco, Alan R.
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Boston Univ, Grad Program Bioinformat, Boston, MA 02215 USA.;Boston Univ, Biol Design Ctr, Boston, MA 02215 USA..
    Sheehy, Sean P.
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Park, Tae-Eun
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Dauth, Stephanie
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Mannix, Robert
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Boston Childrens Hosp, Vasc Biol Program, Boston, MA 02115 USA.;Boston Childrens Hosp, Dept Surg, Boston, MA 02115 USA.;Harvard Med Sch, Boston, MA 02115 USA..
    Budnik, Nikita
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA..
    Shores, Kevin
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Cho, Alexander
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Nawroth, Janna C.
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Segre, Daniel
    Boston Univ, Grad Program Bioinformat, Boston, MA 02215 USA.;Boston Univ, Biol Design Ctr, Boston, MA 02215 USA.;Boston Univ, Dept Phys, Dept Biomed Engn, Dept Biol, 590 Commonwealth Ave, Boston, MA 02215 USA..
    Budnik, Bogdan
    Harvard Univ, Mass Spectrometry & Prote Resource Lab, Cambridge, MA 02138 USA..
    Ingber, Donald E.
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Boston Childrens Hosp, Vasc Biol Program, Boston, MA 02115 USA.;Boston Childrens Hosp, Dept Surg, Boston, MA 02115 USA.;Harvard Med Sch, Boston, MA 02115 USA.;Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Cambridge, MA 02138 USA..
    Parker, Kevin Kit
    Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Dis Biophys Grp, Cambridge, MA 02138 USA.;Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    A linked organ-on-chip model of the human neurovascular unit reveals the metabolic coupling of endothelial and neuronal cells2018In: Nature Biotechnology, ISSN 1087-0156, E-ISSN 1546-1696, Vol. 36, no 9, p. 865-+Article in journal (Refereed)
    Abstract [en]

    The neurovascular unit (NVU) regulates metabolic homeostasis as well as drug pharmacokinetics and pharmacodynamics in the central nervous system. Metabolic fluxes and conversions over the NVU rely on interactions between brain microvascular endothelium, perivascular pericytes, astrocytes and neurons, making it difficult to identify the contributions of each cell type. Here we model the human NVU using microfluidic organ chips, allowing analysis of the roles of individual cell types in NVU functions. Three coupled chips model influx across the blood-brain barrier (BBB), the brain parenchymal compartment and efflux across the BBB. We used this linked system to mimic the effect of intravascular administration of the psychoactive drug methamphetamine and to identify previously unknown metabolic coupling between the BBB and neurons. Thus, the NVU system offers an in vitro approach for probing transport, efficacy, mechanism of action and toxicity of neuroactive drugs.

  • 103.
    Morales, Alvaro
    et al.
    Inst. for Photonic Integration, Eindhoven University of Technology.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Okonkwo, Chigo
    Inst. for Photonic Integration, Eindhoven University of Technology.
    Tafur Monroy, Idelfonso
    Inst. for Photonic Integration, Eindhoven University of Technology.
    Photonic-Based Beamforming System for Sub-THz Wireless Communications2019Conference paper (Refereed)
    Abstract [en]

    This work presents a sub-THz transmitter scheme for wireless communications with beam steering capabilities based on photonics means. A true time delay 1x4 beamforming photonic chip is designed in Si3N4 technology to continuously tune the progressive time delay between consecutive antenna elements. Simulation results show a progressive delay up to 15 ps with a bandwidth of 1.3 GHz, enabling broadband operation at frequencies above 75 GHz. The sub-THz signals are generated on photoconductive antennas on chip by photonic heterodyning. The design of a dielectric rod antenna array is also presented to efficiently radiate the generated wave.

    Download full text (pdf)
    fulltext
  • 104. Novak, R.
    et al.
    Ingram, M.
    Marquez, S.
    Das, D.
    Delahanty, A.
    Herland, Anna
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Maoz, B. M.
    Jeanty, S. S. F.
    Somayaji, M. R.
    Burt, M.
    Calamari, E.
    Chalkiadaki, A.
    Cho, A.
    Choe, Y.
    Chou, D. B.
    Cronce, M.
    Dauth, S.
    Divic, T.
    Fernandez-Alcon, J.
    Ferrante, T.
    Ferrier, J.
    FitzGerald, E. A.
    Fleming, R.
    Jalili-Firoozinezhad, S.
    Grevesse, T.
    Goss, J. A.
    Hamkins-Indik, T.
    Henry, O.
    Hinojosa, C.
    Huffstater, T.
    Jang, K. -J
    Kujala, V.
    Leng, L.
    Mannix, R.
    Milton, Y.
    Nawroth, J.
    Nestor, B. A.
    Ng, C. F.
    O’Connor, B.
    Park, T. -E
    Sanchez, H.
    Sliz, J.
    Sontheimer-Phelps, A.
    Swenor, B.
    Thompson, G. , I I
    Touloumes, G. J.
    Tranchemontagne, Z.
    Wen, N.
    Yadid, M.
    Bahinski, A.
    Hamilton, G. A.
    Levner, D.
    Levy, O.
    Przekwas, A.
    Prantil-Baun, R.
    Parker, K. K.
    Ingber, D. E.
    Robotic fluidic coupling and interrogation of multiple vascularized organ chips2020In: Nature Biomedical Engineering, ISSN 2157-846XArticle in journal (Refereed)
    Abstract [en]

    Organ chips can recapitulate organ-level (patho)physiology, yet pharmacokinetic and pharmacodynamic analyses require multi-organ systems linked by vascular perfusion. Here, we describe an ‘interrogator’ that employs liquid-handling robotics, custom software and an integrated mobile microscope for the automated culture, perfusion, medium addition, fluidic linking, sample collection and in situ microscopy imaging of up to ten organ chips inside a standard tissue-culture incubator. The robotic interrogator maintained the viability and organ-specific functions of eight vascularized, two-channel organ chips (intestine, liver, kidney, heart, lung, skin, blood–brain barrier and brain) for 3 weeks in culture when intermittently fluidically coupled via a common blood substitute through their reservoirs of medium and endothelium-lined vascular channels. We used the robotic interrogator and a physiological multicompartmental reduced-order model of the experimental system to quantitatively predict the distribution of an inulin tracer perfused through the multi-organ human-body-on-chips. The automated culture system enables the imaging of cells in the organ chips and the repeated sampling of both the vascular and interstitial compartments without compromising fluidic coupling.

  • 105.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Micromachined THz Systems - enabling the large-scale exploitation of the THz frequency spectrum2018In: 2018 ASIA-PACIFIC MICROWAVE CONFERENCE PROCEEDINGS (APMC), IEEE , 2018, p. 25-27Conference paper (Refereed)
    Abstract [en]

    Micro-electromechanical (MEMS) devices are ubiquitous in modern society: mobile phones, toys, cars contain MEMS sensors which are manufactured in several billions of devices per year at sub-1 Euro cost. This large-scale utilization of low-cost, highly-miniaturized sensor functions has been enabled by micromachining proving large-scale parallel processing, very high level of integration, excellent product uniformity and very high volume manufacturing capability. State-of-the-art THz technology, however, is still utilizing CNC-milling as the most common packaging and integration technology, which is a sequential fabrication technology which is not scalable to medium to high volumes. This paper summarizes the state of the art in silicon micromachining, discusses advantages and disadvantages and describes several millimeter-wave and submillimeter-wave devices implemented in micromachined waveguide technology, including very-low loss filters, OMTs, couplers, integrated absorbers/attenuators, switches.

  • 106.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Overview and recent achievements in silicon micromachining for THz systems2019In: Proceedings of European Microwave Conference in Central Europe, EuMCE 2019, 2019, p. 23-26Conference paper (Refereed)
    Abstract [en]

    Micromachined sensors, also called electromechanical systems (MEMS), are delivered in several billions of devices per year at sub-1 Euro cost for several applications, including mobile phones, toys, cars. Such a large-scale utilization has been enabled by the key advantages of micromachining as a manufacturing technology, which are: large-scale parallel processing, very high level of miniaturization and integration, excellent product uniformity and very high volume manufacturing capability. In contrast to that, current THz technology is still primarily utilizing CNC-milling, which is a sequential and not scalable fabrication technology. This paper summarizes the state of the art in silicon micromachining, discusses advantages and disadvantages and describes several millimeter-wave and submillimeter-wave devices and systems implemented in micromachined-waveguide technology, including very-low loss filters, OMTs, couplers, integrated absorbers/attenuators, switches

  • 107.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    THz MEMS - Micromachining enabling new solutions at millimeter and submillimeter-wave frequencies (invited paper)2018In: Asia-Pacific Microwave Conference Proceedings, APMC, Institute of Electrical and Electronics Engineers Inc. , 2018, p. 81-84Conference paper (Refereed)
    Abstract [en]

    Since RF MEMS switches appeared more than 20 years ago, micromachining and micromechanics have been receiving large attention for enabling near-ideal microwave devices. MEMS switches and MEMS-switch based circuits have been through different development stages and are currently proving themselves commercially, among others for mobile-phone antenna-tuner switched-capacitor banks. However, micromachining can do much more than just two-dimensional MEMS switches for planar transmission-line technology: Three-dimensional, deep-silicon micromachining allows for new microwave devices with unprecedented performance, and has the potential to become an enabling technology for volume-manufacturable, reconfigurable submillimeter-wave and THz systems. This paper provides an overview of 3D silicon micromachining capability, and recent achievements of innovative microwave devices and systems enabled by micromachining high up into the THz spectrum are given, including the first MEMS-reconfigurable submillimeter-wave devices. Highlights of devices presented are a 3.3 bit MEMS phase shifter and a low-insertion loss / high-isolation MEMS waveguide switch operating at 500-750 GHz, and a micromachined technology for multi-pole, multi-transmission zero filers which enables multi-mode resonators with Q factors of 800 at 270 GHz. Furthermore, a technology is shown for very low loss micromachined waveguides with only 0.02 dB/mm loss at 200-300 GHz, which has enabled ultra-low loss waveguide components such as couplers and power combiners/splitters. 

  • 108.
    Ottonello Briano, Floria
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Mid-infrared photonic devices for on-chip optical gas sensing2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift.

    Wavelengths between 3 and 10 μm are of particular interest for gas sensing. This spectral range, called the mid-infrared (mid-IR), is also known as the fingerprint region, because several gas species can be identified by their sharp absorption lines in this region. The most relevant mid-IR-active gases are the trace gases carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), ammonia (NH3), and nitrous oxide (N2O). They are greenhouse gases, contributing to global warming. They are waste products of human activities and widely used in agriculture and industry. Therefore, it is crucial to accurately and extensively monitor them. However, traditional optical gas sensors with a free-space optical path configuration, are too bulky, power-hungry, and expensive to be widely adopted.

    This thesis presents mid-IR integrated photonic devices that enable the on-chip integration of optical gas sensors, with a focus on CO2 sensing. The reported technologies address the fundamental sensor functionalities: light-gas interaction, infrared light generation, and infrared light detection. The thesis introduces a novel mid-IR silicon photonic waveguide that allows a light path as long as tens of centimeters to fit in a volume smaller than a few cubic millimeters. Mid-IR CO2 spectroscopy demonstrates the high sensing performance of the waveguide. The thesis also explores the refractive index sensing of CO2 with a mid-IR silicon photonic micro-ring resonator.

    Furthermore, the thesis proposes platinum nanowires as low-cost infrared light sources and detectors that can be easily integrated on photonic waveguides. Finally, the thesis presents a large-area infrared emitter fabricated by highs-peed wire bonding and integrated in a non-dispersive infrared sensor for the detection of alcohol in breath.

    The technologies presented in this thesis are suited for cost-effective mass production and large-scale adoption. Miniaturized integrated optical gas sensors have the potential to become the main choice for an increasingly broad range of existing and new applications, such as portable, distributed, and networked environmental monitoring, and high-volume medical and consumer applications.

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    OttonelloBriano_PhDthesis
  • 109.
    Ottonello Briano, Floria
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Rödjegård, Henrik
    Martin, Hans
    Sohlström, Hans
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Carbon dioxide absorption spectroscopy with a mid-infrared silicon photonic waveguide2020In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 45, no 1, p. 109-112Article in journal (Refereed)
    Abstract [en]

    Carbon dioxide (CO2) is a gas vital for life on Earth. It is also a waste product of human activities and is widely used in agriculture and industry. Its accurate sensing is therefore of great interest. Optical sensors exploiting the mid-infrared light absorption of CO2 provide high selectivity, but their large size and high cost limit their use. In this Letter, we demonstrate CO2 gas sensing at 4.2 µm wavelength using an integrated silicon waveguide, featuring a sensitivity to CO2 of 44% that of free-space sensing. The suspended waveguide is fabricated on a silicon-on-insulator substrate by a single-lithography-step process, and we route it into a mid-infrared photonic circuit for on-chip-referenced gas measurements. Its demonstrated performance and its simple and scalable fabrication make our waveguide ideal for integration in miniaturized CO2 sensors for distributed environmental monitoring, personal safety, and medical and high-volume consumer applications.

    Download full text (pdf)
    fulltext
  • 110.
    Ottonello-Briano, Floria
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    On-chip dispersion spectroscopy of mid-infrared molecular fingerprints using a microring resonatorManuscript (preprint) (Other academic)
  • 111.
    Ottonello-Briano, Floria
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems. Senseair AB.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Quantum Photonics Laboratory, MIT.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    On-chip dispersion spectroscopy of CO2 using a mid-infrared microring resonator2020In: Proceedings of 2020 CLEO Technical Conference, 2020Conference paper (Refereed)
    Abstract [en]

    We demonstrate on-chip molecular fingerprinting by measuring the refractive index dispersion of gas in the mid-IR using a thermally tuned suspended silicon microring resonator. We show CO2 sensing down to 1000 ppm at 4.23 µm wavelength.

    Download full text (pdf)
    Ottonello-Briano_CLEO2020_STh1N.3
  • 112.
    Ottonello-Briano, Floria
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Rödjegård, Henrik
    Martin, Hans
    Sohlström, Hans
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems. KTH, Superseded Departments (pre-2005), Electrical Systems.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Carbon dioxide absorption spectroscopy with a mid-infrared silicon photonic waveguideManuscript (preprint) (Other academic)
    Abstract [en]

    Carbon dioxide is a vital gas for life on Earth, a waste product of human activities, and widely used in agriculture and industry. Its accurate sensing is therefore of great interest. Optical sensors exploiting the mid-infrared light absorption of CO2 provide high selectivity, but their large size and high cost limit their use. Here, we demonstrate CO2 gas sensing at 4.2 μm wavelength using an integrated silicon waveguide, featuring a sensitivity to CO2 of 44% that of free-space sensing. The suspended waveguide is fabricated on a silicon-on-insulator substrate by a single-lithography-step process, and we route it into a mid-infrared photonic circuit for on-chip-referenced gas measurements. Its demonstrated performance and its simple and scalable fabrication make our waveguide ideal for integration in miniaturized CO2 sensors for distributed environmental monitoring, personal safety, medical, and high-volume consumer applications.

  • 113.
    Ottonello-Briano, Floria
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Rödjegård, Henrik
    Senseair AB.
    Martin, Hans
    Senseair AB.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Carbon Dioxide Sensing with Low-confinementHigh-sensitivity Mid-IR SiliconWaveguides2019In: Conference on Lasers and Electro-Optics 2019: CLEO: Science and Innovations, 2019, article id STh1F.3Conference paper (Refereed)
    Abstract [en]

    We present a low-confinement Si waveguide for 4.26 μm wavelength and applyit to sense CO2 concentrations down to 0.1 %. We demonstrate the highest reportedwaveguide sensitivity to CO2: 44% of the free-space sensitivity.

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    fulltext
  • 114.
    Pagliano, Simone
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Gota, Fabrizio
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Raja, Shyamprasad Natarajan
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Dubois, Valentin J.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Feedback-free electromigrated tunneling junctions from crack-defined gold nanowires2019In: Feedback-free electromigrated tunneling junctions from crack-defined gold nanowires, 2019Conference paper (Refereed)
    Abstract [en]

    Tunneling junctions are pairs of electrodes separated by gaps of a few nanometers (< 3 nm) that allow electrons to tunnel across the gap. Tunneling junctions are of great importance for applications such as label-free biomolecule sensing and single molecule electronics, but their fabrication remains difficult and laborious. In this paper, we present a simple 2-stage process for the fabrication of tunneling junctions consisting of electrode pairs made of gold (Au). This is achieved by combining a novel methodology for fabricating crack-defined Au nanowires at wafer-scale with a constant voltage, feedback-free electromigration procedure to form tunneling nanogaps free of debris.

  • 115.
    Pagliano, Simone
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Gota, Fabrizio
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Raja, Shyamprasad Natarajan
    Dubois, Valentin J.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Stemme, Göran
    KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems. KTH, Superseded Departments (pre-2005), Biotechnology. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Feedback-Free Electromigrated Tunneling Junctions from Crack-Defined Gold Nanowires2019In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE conference proceedings, 2019, p. 365-367Conference paper (Refereed)
    Abstract [en]

    Tunneling junctions are pairs of electrodes separated by gaps of a few nanometers that allow electrons to tunnel across the gap. Tunneling junctions are of great importance for applications such as label-free biomolecule sensing and single molecule electronics, but their fabrication remains difficult and laborious. In this paper, we present a simple 2-stage process for the fabrication of tunneling junctions consisting of electrode pairs made of gold (Au). This is achieved by combining a novel methodology for fabricating crack-defined Au nanowires at wafer-scale with a constant voltage, feedback-free electromigration procedure to form tunneling nanogaps free of debris.

  • 116.
    Park, Tae-Eun
    et al.
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;UNIST, UNIST Gil 50, Ulsan 44919, South Korea..
    Mustafaoglu, Nur
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Herland, Anna
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Harvard Univ, USA ;Karolinska Inst, Swedish Med Nanosci Ctr, Dept Neurosci, Stockholm, Sweden..
    Hasselkus, Ryan
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Mannix, Robert
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Harvard Med Sch, Boston, MA 02115 USA.;Boston Childrens Hosp, Vasc Biol Program, Boston, MA 02115 USA.;Boston Childrens Hosp, Dept Surg, Boston, MA 02115 USA..
    FitzGerald, Edward A.
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Prantil-Baun, Rachelle
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Watters, Alexander
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Henry, Olivier
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Benz, Maximilian
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    Sanchez, Henry
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA..
    McCrea, Heather J.
    Boston Childrens Hosp, Dept Neurosurg, Boston, MA 02115 USA.;Harvard Med Sch, Boston, MA 02115 USA..
    Goumnerova, Liliana Christova
    Boston Childrens Hosp, Dept Neurosurg, Boston, MA 02115 USA.;Harvard Med Sch, Boston, MA 02115 USA..
    Song, Hannah W.
    Univ Wisconsin, Dept Chem & Biol Engn, Madison, WI 53706 USA..
    Palecek, Sean P.
    Univ Wisconsin, Dept Chem & Biol Engn, Madison, WI 53706 USA..
    Shusta, Eric
    Univ Wisconsin, Dept Chem & Biol Engn, Madison, WI 53706 USA..
    Ingber, Donald E.
    Harvard Univ, Wyss Inst Biol Inspired Engn, Boston, MA 02115 USA.;Harvard Med Sch, Boston, MA 02115 USA.;Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Cambridge, MA 02138 USA.;Boston Childrens Hosp, Vasc Biol Program, Boston, MA 02115 USA.;Boston Childrens Hosp, Dept Surg, Boston, MA 02115 USA..
    Hypoxia-enhanced Blood-Brain Barrier Chip recapitulates human barrier function and shuttling of drugs and antibodies2019In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, article id 2621Article in journal (Refereed)
    Abstract [en]

    The high selectivity of the human blood-brain barrier (BBB) restricts delivery of many pharmaceuticals and therapeutic antibodies to the central nervous system. Here, we describe an in vitro microfluidic organ-on-a-chip BBB model lined by induced pluripotent stem cell-derived human brain microvascular endothelium interfaced with primary human brain astrocytes and pericytes that recapitulates the high level of barrier function of the in vivo human BBB for at least one week in culture. The endothelium expresses high levels of tight junction proteins and functional efflux pumps, and it displays selective transcytosis of peptides and antibodies previously observed in vivo. Increased barrier functionality was accomplished using a developmentally-inspired induction protocol that includes a period of differentiation under hypoxic conditions. This enhanced BBB Chip may therefore represent a new in vitro tool for development and validation of delivery systems that transport drugs and therapeutic antibodies across the human BBB.

  • 117.
    Parrilla, Marc
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Cuartero, Maria
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Sanchez, Sara Padrell
    Karolinska Inst, Dept Clin Sci Intervent & Technol, K 57, SE-14186 Stockholm, Sweden.;Karolinska Univ Sjukhuset, Div Obstet & Gynecol, S-14186 Stockholm, Sweden..
    Rajabi, Mina
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Crespo, Gaston A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Wearable All-Solid-State Potentiometric Microneedle Patch for Intradermal Potassium Detection2019In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 91, no 2, p. 1578-1586Article in journal (Refereed)
    Abstract [en]

    A new analytical all-solid-state platform for intradermal potentiometric detection of potassium in interstitial fluid is presented here. Solid microneedles are modified with different coatings and polymeric membranes to prepare both the potassium-selective electrode and reference electrode needed for the potentiometric readout. These microneedle-based electrodes are fixed in an epidermal patch suitable for insertion into the skin. The analytical performances observed for the potentiometric cell (Nernstian slope, limit of detection of 10(-4.9) potassium activity, linear range of 10(-4.2) to 10(-1.1), drift of 0.35 +/- 0.28 mV h(-1)), together with a fast response time, adequate selectivity, and excellent reproducibility and repeatability, are appropriate for potassium analysis in interstitial fluid within both clinical and harmful levels. The potentiometric response is maintained after several insertions into animal skin, confirming the resiliency of the microneedle-based sensor. Ex vivo tests based on the intradermal detection of potassium in chicken and porcine skin demonstrate that the microneedle patch is suitable for monitoring potassium changes inside the skin. In addition, the dimensions of the microneedles modified with the corresponding layers necessary to enhance robustness and provide sensing capabilities (1000 mu m length, 45 degrees tip angle, 15 mu m thickness in the tip, and 435 mu m in the base) agree with the required ranges for a painless insertion into the skin. In vitro cytotoxicity experiments showed that the patch can be used for at least 24 h without any side effect for the skin cells. Overall, the developed concept constitutes important progress in the intradermal analysis of ions related to an electrolyte imbalance in humans, which is relevant for the control of certain types of diseases.

  • 118. Poxson, D. J.
    et al.
    Gabrielsson, E. O.
    Bonisoli, A.
    Linderhed, U.
    Abrahamsson, T.
    Matthiesen, Isabelle
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Tybrandt, K.
    Berggren, M.
    Simon, D. T.
    Capillary-Fiber Based Electrophoretic Delivery Device2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 15, p. 14200-14207Article in journal (Refereed)
    Abstract [en]

    Organic electronic ion pumps (OEIPs) are versatile tools for electrophoretic delivery of substances with high spatiotemporal resolution. To date, OEIPs and similar iontronic components have been fabricated using thin-film techniques and often rely on laborious, multistep photolithographic processes. OEIPs have been demonstrated in a variety of in vitro and in vivo settings for controlling biological systems, but the thin-film form factor and limited repertoire of polyelectrolyte materials and device fabrication techniques unnecessarily constrain the possibilities for miniaturization and extremely localized substance delivery, e.g., the greater range of pharmaceutical compounds, on the scale of a single cell. Here, we demonstrate an entirely new OEIP form factor based on capillary fibers that include hyperbranched polyglycerols (dPGs) as the selective electrophoretic membrane. The dPGs enable electrophoretic channels with a high concentration of fixed charges and well-controlled cross-linking and can be realized using a simple "one-pot" fluidic manufacturing protocol. Selective electrophoretic transport of cations and anions of various sizes is demonstrated, including "large" substances that are difficult to transport with other OEIP technologies. We present a method for tailoring and characterizing the electrophoretic channels' fixed charge concentration in the operational state. Subsequently, we compare the experimental performance of these capillary OEIPs to a computational model and explain unexpected features in the ionic current for the transport and delivery of larger, lower-mobility ionic compounds. From this model, we are able to elucidate several operational and design principles relevant to miniaturized electrophoretic drug delivery technologies in general. Overall, the compactness of the capillary OEIP enables electrophoretic delivery devices with probelike geometries, suitable for a variety of ionic compounds, paving the way for less-invasive implantation into biological systems and for healthcare applications.

  • 119.
    Quack, Niels
    et al.
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Sattari, Hamed
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Takabayashi, Alain Y.
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Zhang, Yu
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Edinger, Pierre
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Jezzini, Moises A.
    Tyndall Natl Inst, Lee Maltings Complex Dyke Parade, Cork T12 R5CP, Ireland..
    Hwang, How Yuan
    Tyndall Natl Inst, Lee Maltings Complex Dyke Parade, Cork T12 R5CP, Ireland..
    O'Brien, Peter
    Tyndall Natl Inst, Lee Maltings Complex Dyke Parade, Cork T12 R5CP, Ireland..
    Porcel, Marco A. G.
    Univ Politecn Valencia, VLC Photon SL, Ed 9B,D2,Camino Vera Sn, Valencia 46022, Spain..
    Arce, Cristina Lerma
    Commscope Connect Belgium, Diestsesteenweg 692, B-3010 Kessel Lo, Belgium..
    Kumar, Saurav
    Commscope Connect Belgium, Diestsesteenweg 692, B-3010 Kessel Lo, Belgium..
    Abasahl, Banafsheh
    Univ Ghent, IMEC, Dept Informat Technol, Photon Res Grp, Technol Pk Zwijnaarde 15, B-9052 Ghent, Belgium..
    Verheyen, Peter
    Univ Ghent, IMEC, Dept Informat Technol, Photon Res Grp, Technol Pk Zwijnaarde 15, B-9052 Ghent, Belgium..
    Bogaerts, Wim
    Univ Ghent, IMEC, Dept Informat Technol, Photon Res Grp, Technol Pk Zwijnaarde 15, B-9052 Ghent, Belgium..
    Silicon Photonic MEMS: Exploiting Mechanics at the Nanoscale to Enhance Photonic Integrated Circuits2019In: 2019 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC), IEEE , 2019Conference paper (Refereed)
    Abstract [en]

    With the maturing and the increasing complexity of Silicon Photonics technology, novel avenues are pursued to reduce power consumption and to provide enhanced functionality: exploiting mechanical movement in advanced Silicon Photonic Integrated Circuits provides a promising path to access a strong modulation of the effective index and to low power consumption by employing mechanically stable and thus non-volatile states. In this paper, we will discuss recent achievements in the development of MEMS enabled systems in Silicon Photonics and outline the roadmap towards reconfigurable general Photonic Integrated Circuits.

  • 120. Quack, Niels
    et al.
    Sattari, Hamed
    Takabayashi, Alain Yuji
    Zhang, Yu
    Edinger, Pierre
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Errando-Herranz, Carlos
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    MEMS-based silicon photonic integrated devices and circuits2019Conference paper (Other academic)
  • 121. Quack, Niels
    et al.
    Sattari, Hamed
    Takabayashi, Alain Yuji
    Zhang, Yu
    Edinger, Pierre
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Jezzini, Moises
    Hwang, H. Y.
    O'Brien, Peter
    Porcel, Marco
    Arce, Cristina
    Kumar, Saurav
    Abasahl, Banafsheh
    Verheyen, Peter
    Bogaerts, Wim
    Exploiting Mechanics at the Nanoscale to Enhance Photonic Integrated Circuits2019In: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2019, p. 1-3, article id 8696652Conference paper (Refereed)
    Abstract [en]

    With the maturing and the increasing complexity of Silicon Photonics technology, novel avenues are pursued to reduce power consumption and to provide enhanced functionality: exploiting mechanical movement in advanced Silicon Photonic Integrated Circuits provides a promising path to access a strong modulation of the effective index and to low power consumption by employing mechanically stable and thus non-volatile states. In this paper, we will discuss recent achievements in the development of MEMS enabled systems in Silicon Photonics and outline the roadmap towards reconfigurable general Photonic Integrated Circuits.

  • 122. Quack, Niels
    et al.
    Sattari, Hamed
    Takabayashi, Alain Yuji
    Zhang, Yu
    Errando-Herranz, Carlos
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Edinger, Pierre
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Exploiting Mechanics at the Micro- and Nanoscale for Efficient Reconfiguration of Photonic Integrated Circuits2019In: IEEE Photonics Society Summer Topical Meeting Series 2019, SUM 2019, 2019, p. 1-1, article id 8795036Conference paper (Refereed)
    Abstract [en]

    We exploit Micro- & Nano-Electro-Mechanical Systems in Photonic Integrated Circuits to perform basic photonic operations, including phase shifting, attenuation and switching. Due to their small footprint and low insertion loss, Photonic MEMS are highly scalable, while mechanical latching mechanisms can offer zero steady state power consumption.

  • 123.
    Quack, Niels
    et al.
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Sattari, Hamed
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Takabayashi, Alain Yuji
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland..
    Zhang, Yu
    Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland.;Beihang Univ, Beijing 100083, Peoples R China..
    Verheyen, Peter
    Interuniv Microelect Ctr IMEC, B-3001 Leuven, Belgium..
    Bogaerts, Wim
    Interuniv Microelect Ctr IMEC, Dept Informat Technol, B-3001 Leuven, Belgium.;Ctr Nano & Biophoton NB Photon, B-9000 Ghent, Belgium..
    Edinger, Pierre
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    MEMS-Enabled Silicon Photonic Integrated Devices and Circuits2020In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 56, no 1, article id 8400210Article in journal (Refereed)
    Abstract [en]

    Photonic integrated circuits have seen a dramatic increase in complexity over the past decades. This development has been spurred by recent applications in datacenter communications and enabled by the availability of standardized mature technology platforms. Mechanical movement of wave-guiding structures at the micro- and nanoscale provides unique opportunities to further enhance functionality and to reduce power consumption in photonic integrated circuits. We here demonstrate integration of MEMS-enabled components in a simplified silicon photonics process based on IMEC's Standard iSiPP50G Silicon Photonics Platform and a custom release process.

  • 124.
    Quellmalz, Arne
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Smith, Anderson David
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Elgammal, Karim
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Fan, Xuge
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Delin, Anna
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Östling, Mikael
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Integrated devices and circuits.
    Lemme, Max C.
    Chair of Electronic Devices, RWTH Aachen University.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Influence of Humidity on Contact Resistance in Graphene Devices2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 48, p. 41738-41746Article in journal (Refereed)
    Abstract [en]

    The electrical contact resistance at metal–graphene interfaces can significantly degrade the properties of graphene devices and is currently hindering the full exploitation of graphene’s potential. Therefore, the influence of environmental factors, such as humidity, on the metal–graphene contact resistance is of interest for all graphene devices that operate without hermetic packaging. We experimentally studied the influence of humidity on bottom-contacted chemical-vapor-deposited (CVD) graphene–gold contacts, by extracting the contact resistance from transmission line model (TLM) test structures. Our results indicate that the contact resistance is not significantly affected by changes in relative humidity (RH). This behavior is in contrast to the measured humidity sensitivity  of graphene’s sheet resistance. In addition, we employ density functional theory (DFT) simulations to support our experimental observations. Our DFT simulation results demonstrate that the electronic structure of the graphene sheet on top of silica is much more sensitive to adsorbed water molecules than the charge density at the interface between gold and graphene. Thus, we predict no degradation of device performance by alterations in contact resistance when such contacts are exposed to humidity. This knowledge underlines that bottom-contacting of graphene is a viable approach for a variety of graphene devices and the back end of the line integration on top of conventional integrated circuits.

  • 125.
    Quellmalz, Arne
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wagner, Stefan
    Lemme, Max
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wafer-Scale Transfer of Graphene by Adhesive Wafer Bonding2019Conference paper (Refereed)
    Abstract [en]

    Graphene is an extremely promising material for emerging nanoelectromechanical systems (NEMS) and sensors, but the transfer from its growth substrate to silicon substrates remains manual and laborious. We report a novel method for the transfer of large-area chemical vapor deposited (CVD) graphene from copper foil to a target wafer by adhesive wafer bonding using bisbenzocyclobutene (BCB) as an intermediate adhesive layer. The use of conventional wafer bonding equipment enables the scalable transfer of graphene and the realization of both supported and suspended graphene devices on wafer-scale. Our method circumvents manual handling of graphene after release from its growth substrate and avoids polymeric carrier layers, a well-known source of contamination. Hence, the proposed process promises the transfer of graphene with high quality and repeatability.

  • 126.
    Quellmalz, Arne
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wagner, Stefan
    Sawallich, Simon
    Lemme, Max C.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Large-scale Integration of 2D Material Heterostructures by Adhesive Bonding2020Conference paper (Refereed)
    Abstract [en]

    We report the integration of graphene/hexagonal boron nitride (hBN) heterostructure devices on large-areas by adhesive wafer bonding, a method suitable for industrial mass-production. In this new approach, we stack graphene and hBN by two consecutive bond transfers whereby the graphene and its interface to hBN is not in contact with potentially contaminating polymers or adhesives at any time. To show the feasibility of our approach for back end of the line (BEOL) integration of two-dimensional (2D) material heterostructures on standard silicon substrates, we fabricated graphene/hBN devices with electrical bottom contacts using only established semiconductor manufacturing tools, processes and materials.

  • 127.
    Quellmalz, Arne
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Wagner, Stefan
    AMO GmbH, Advanced Microelectronic Center Aachen (AMICA).
    Sawallich, Simon
    Protemics GmbH; Chair of Electronic Devices, Faculty of Electrical Engineering and Information Technology, RWTH Aachen University.
    Prechtl, Maximilian
    Institute of physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr München.
    Hartwig, Oliver
    Institute of physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr München.
    Luo, Siwei
    Institute of physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr München.
    S. Duesberg, Georg
    Institute of physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr München.
    Lemme, Max
    AMO GmbH, Advanced Microelectronic Center Aachen (AMICA); Chair of Electronic Devices, Faculty of Electrical Engineering and Information Technology, RWTH Aachen University.
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Large-Area Integration of Two-Dimensional Materials and Their Heterostructures Using Wafer Bonding2019In: Article in journal (Other academic)
  • 128.
    Rajabi, Mina
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH.
    Flexible and Stretchable Biointerfacing for Healthcare Diagnostics2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Flexible and stretchable wearable biomedical devices provide a platform for continues long-term monitoring of biological signals during neutral body movements thus enabling early intervention and diagnostics of various diseases. This thesis evaluates novel flexible and stretchable bio interfacing medical devices based on microneedle patches and split ring resonator for healthcare diagnostics. Flexible and stretchable microneedle patches were realized by integrating a soft polymer substrate with sharp stainless steel microneedles. This was realized using a magnetic assembly technique. Investigations have shown that the flexible microneedle patch can provide conformal and reliable contact with wrinkles and deformations of the skin. In addition, transdermal monitoring of potassium ions using the proposed flexible microneedle patch have been demonstrated by coating the microneedles with a potassium sensing membrane. Ex-vivo test on the microneedle potassium sensor performed on chicken and porcine skin was able to detect change in potassium concentration in the skin. Furthermore, a novel flexible bio-interface spilt ring resonator (SRR) for the monitoring of intera cranial pressure (ICP) is demonstrated. The sensor was fabricated by depositing a 500 nm gold film on a thermoset thiolene epoxy polymer substrate. The flexible sensor was able to clearly detect the pressure variation that might be an indication of increased ICP in the skull. The proposed methodology of heterogeneous integration of hard materials on a soft and flexible substrate demonstrates a first proof of concept of flexible wearable bio-interfacing devices with vastly different material properties with the potential for continuous and real-time health monitoring.

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  • 129.
    Rana, Sunil
    et al.
    University of Bristol.
    Mouro, João
    University of Bristol.
    Bleiker, Simon J.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Reynolds, Jamie D.
    University of Southampton.
    Chong, Harold M. H.
    University of Southampton.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Pamunuwa, Dinesh
    University of Bristol.
    Nanoelectromechanical relay without pull-in instability for high-temperature non-volatile memory2020In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 11, no 1, article id 1181Article in journal (Refereed)
    Abstract [en]

    Emerging applications such as the Internet-of-Things and more-electric aircraft require electronics with integrated data storage that can operate in extreme temperatures with high energy efficiency. As transistor leakage current increases with temperature, nanoelectromechanical relays have emerged as a promising alternative. However, a reliable and scalable non-volatile relay that retains its state when powered off has not been demonstrated. Part of the challenge is electromechanical pull-in instability, causing the beam to snap in after traversing a section of the airgap. Here we demonstrate an electrostatically actuated nanoelectromechanical relay that eliminates electromechanical pull-in instability without restricting the dynamic range of motion. It has several advantages over conventional electrostatic relays, including low actuation voltages without extreme reduction in critical dimensions and near constant actuation airgap while the device moves, for improved electrostatic control. With this nanoelectromechanical relay we demonstrate the first high-temperature non-volatile relay operation, with over 40 non-volatile cycles at 200 °C.

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    fulltext
  • 130. Redzwan, S.
    et al.
    Velander, J.
    Perez, M. D.
    Asan, N. B.
    Rajabi, Mina
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Nowinski, D.
    Lewén, A.
    Enblad, P.
    Augustine, R.
    Initial in-vitro trial for intra-cranial pressure monitoring using subdermal proximity-coupled split-ring resonator2018In: IMBioc 2018 - 2018 IEEE/MTT-S International Microwave Biomedical Conference, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 73-75, article id 8428854Conference paper (Refereed)
    Abstract [en]

    Intra cranial pressure (ICP) monitoring is used in treating severe traumatic brain injury (TBI) patients. All current clinical available measurement methods are invasive presenting considerable social costs. This paper presents a preliminary investigation of the feasibility of ICP monitoring using an innovative microwave-based non-invasive approach. A phantom mimicking the dielectric characteristics of human tissues of the upper part of the head at low microwave frequencies is employed together to a proof-of-concept prototype based on the proposed approach consisting in a readout system and a sub-dermally implanted passive device, both based in split ring resonator techniques. This study shows the potential of our approach to detect two opposite pressure variation stages inside the skull. The employed phantom model needs to be improved to support finer variations in the pressure and better phantom parts, principally for the skull mimic and the loss tangent of all mimics.

  • 131.
    Ribet, Federico
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Integrated microsystems for continuous glucose monitoring, interstitial fluid sampling and digital microfluidics2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Interdisciplinary research between medicine and microsystem engineering creates new possibilities to improve the quality of life of patients or to further enhance the performance of already existing devices. In particular, microsystems show great potential for the realization of biosensors and sampling devices to monitor bioanalytes with minimal patient discomfort. Microneedles offer a minimally invasive and painless solution to penetrate the epidermis and provide access to dermal interstitial fluid (ISF), to monitor various substances without the need for more invasive and painful extraction of blood. Diabetes, for example, requires continuous monitoring of the glucose levels in the body (CGM) to avoid complications. Although glucose is traditionally measured in finger-prick blood, CGM, which is performed in ISF, has been proven to be beneficial in the management of the disease. However, current commercial solutions are still relatively large and invasive. In this work, an electrochemical glucose sensor 50 times smaller than competing commercial devices was combined with a hollow silicon microneedle and shown to be able to measure glucose levels in the dermis in vivo. A scalable manufacturing method for the assembly of the two separately fabricated components and their electrical interconnection was also demonstrated. At the same time, a single data point may be sufficient in other situations, such as when only the presence of a certain biomarker or drug needs to be assessed. Although continuous monitoring is not required in these cases, the patient would still benefit by avoiding blood extraction. However, there are no simple devices currently available to reliably sample and store ISF. A painless microneedle-based sampling device designed to extract 1 μL of ISF from the dermis was realized. The sampled liquid is metered and stored in a paper matrix embedded in a microfluidic chip. The sample could then be analyzed using state-of-the-art tools, such as mass spectrometry.On the other hand, device miniaturization also creates issues for sensor performance. In certain types of electrochemical gas sensors, such as nitric oxide sensors used for asthma monitoring, the reduced size results in a shorter device lifetime. These sensors typically operate with a liquid electrolyte, subject to evaporation, and their long-term stability tends to be proportional to the electrode size. To address this issue, a gas diffusion and evaporation controlling platform to be integrated with this type of sensors was proposed. Such a platform opens or seals the sensing compartment on demand, potentially enabling sensor recalibration and evaporation reduction when the sensor is not in use. The device is based on electrowetting-on-dielectric actuation of low-vapor-pressure ionic liquid microdroplets on partially perforated membranes. The platform was then modified to create a zero-insertion loss and broad-band-operation laser shutter.

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  • 132.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    De Luca, Eleonora
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Ottonello Briano, Floria
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Swillo, Marcin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Zero-insertion-loss optical shutter based on electrowetting-on-dielectric actuation of opaque ionic liquid microdroplets2019In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 115, no 7, article id 073502Article in journal (Refereed)
    Abstract [en]

    This article reports a broad-band optical shutter based on microdroplet actuation with zero optical insertion loss in the open state. These features are achieved by electrowetting-on-dielectric (EWOD) actuation of opaque ionic liquid microdroplets. The negligible vapor pressure of ionic liquids allows the device to robustly operate in open air, unlike previously proposed EWOD-based systems in which the light crosses several attenuating and reflective layers, preventing broad-band operation and creating insertion losses > 14%. The presented device provides an attenuation of 78dB in the closed state and a transmission of >99.99999% in the open state and can operate in the visible and mid-infrared wavelength range. Moreover, the switch can sustain larger incoming laser powers (5 mW continuous exposure or up to 3h of continuous exposure at similar to 100mW) compared to the values reported for other state-of-the-art EWOD-based shutters. Additionally, the proposed device is compact, operates with low voltage (<25V peak voltage), and features zero static power consumption.

  • 133.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    De Luca, Eleonora
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Ottonello Briano, Floria
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Swillo, Marcin
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Zero-Loss Optical Switch Based on Ionic Liquid Microdroplet Ewod Actuatio2019In: 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems and Eurosensors XXXIII, TRANSDUCERS 2019 and EUROSENSORS XXXIII, Institute of Electrical and Electronics Engineers (IEEE), 2019, p. 2290-2293, article id 8808243Conference paper (Refereed)
    Abstract [en]

    This paper reports the first optical shutter based on electrical actuation of microdroplets featuring zero insertion loss in the open state and broad-band operation. These features are achieved by electrowetting-on-dielectric (EWOD) actuation of ionic liquid microdroplets. Due to their negligible vapor pressure, ionic liquids allow the switch to robustly operate in air, unlike previously proposed systems in which the light had to cross several attenuating and refractive layers. Moreover, this solution enables operation in a much wider wavelength range, e.g. in the infrared spectrum where glass has strong absorption. Additionally, the proposed device requires lower voltage to operate (25 V) and features zero static power consumption.

  • 134.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    De Pietro, Luca
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Gas diffusion and evaporation control using EWOD actuation of ionic liquid microdroplets for gas sensing applications2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 267, p. 647-654Article in journal (Refereed)
    Abstract [en]

    The lifetime of electrochemical gas sensors suffers from electrolyte evaporation and from the impracticality to perform recalibration. To tackle these issues, a prototype of a microfabricated gas diffusion controlling system, based on coplanar electrowetting-on-dielectric (EWOD) actuation of ionic liquid microdroplets, is presented. The system is designed to be integrated with electrochemical gas sensors to allow on-demand sealing of the sensing chamber from the environment. The MEMS device can be electrically toggled between an open and a closed state, in which the microdroplets are used to cover or uncover the openings of a perforated membrane connecting to the sensing compartment, respectively. This ON/OFF diffusion-blocking valve mechanism potentially allows for recalibration and for liquid electrolyte evaporation reduction when the sensor is not in use, thus extending the gas sensor lifetime. A one order of magnitude reduction of evaporation rate and a more than three orders of magnitude reduction of gas diffusion time were experimentally demonstrated. Ionic liquid movement can be performed with an applied AC voltage as low as 18 V, using super-hydrophobic cover plates to facilitate droplet motion. Furthermore, the shown ionic liquid micro-droplet manipulation provides a robust and low voltage platform for digital microfluidics, readily adaptable to serve different applications.

  • 135.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    De Pietro, Luca
    KTH.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Ionic liquid microdroplet manipulation by electrowetting-on-dielectric for on/off diffusion control2018In: 2018 IEEE Micro Electro Mechanical Systems (MEMS), Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1181-1184Conference paper (Refereed)
    Abstract [en]

    This article presents a proof-of-concept of a device able to control (ON/OFF) gas diffusion through a perforated membrane. The microfabricated system is based on electrowetting-on-dielectric (EWOD) actuation of ionic liquid (IL) microdroplets and can be electrically toggled from an open to a closed state, in which microdroplets cover or uncover the membrane openings, respectively. The system is designed to be integrated with liquid-electrolyte-based electrochemical gas sensors, to extend their lifetime by reducing electrolyte evaporation and allowing recalibration. The realized device was proven to limit gas diffusion and water evaporation through perforated portions of thin membranes on command.

  • 136.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH.
    Dobielewski, Mikolaj
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Böttcher, Michael
    Beck, Olof
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Minimally invasive and volume-metered extraction of interstitial fluid:bloodless point-of-care sampling for bioanalyte detectionManuscript (preprint) (Other academic)
    Abstract [en]

    Sampling of biological fluids is fundamental in health monitoring and, currently, blood analysisis the standard practice. However, blood sampling entails a series of drawbacks including pain,discomfort, and risk of infections. Interstitial fluid, having a good correlation with blood concentrationdynamics for several analytes, is a promising alternative monitoring matrix because it can be sampled ina minimally invasively manner from the skin, without the need for the more invasive and painfulextraction methods used for blood. Currently, there are no simple devices available to sample and storeknown amounts of interstitial fluid. In this work, a painless microneedle-based sampling device designedto extract 1 μL of fluid from the dermis was realized. The sampled liquid is metered and stored in a papermatrix embedded in a microfluidic chip. The sample can then be analyzed using state-of-the-art tools,such as mass spectrometry (LC-MS/MS).

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  • 137.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    Microneedle-based system for minimally invasive continuous monitoring of glucose in the dermal interstitial fluid2018In: 2018 IEEE Micro Electro Mechanical Systems (MEMS), Institute of Electrical and Electronics Engineers (IEEE), 2018, Vol. 2018, p. 408-411Conference paper (Refereed)
    Abstract [en]

    We present a minimally invasive continuous glucose monitoring (CGM) device. The system consists in an ultra-miniaturized electrochemical sensor probe (70 × 700 × 50 μm3) inserted into the lumen of a hollow silicon microneedle. The implantable portion of the system is 50-fold smaller than state-of-the-art commercial products, thus enabling glucose monitoring in the dermis and a less invasive insertion procedure. Passive interstitial fluid extraction is achieved, making the daily use of this system practically viable. Moreover, the sensor positioning provides minimal delay in tracking glycaemia (5-10 minutes lag), due to the minimal distance between sensing electrodes and microneedle opening. The demonstrated system has therefore the potential to enable minimally invasive, fast and reliable CGM in patients affected by diabetes.

  • 138.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Real-time intradermal continuous glucose monitoring using a minimally invasive microneedle-based system2018In: Biomedical microdevices (Print), ISSN 1387-2176, E-ISSN 1572-8781, Vol. 20, no 4, article id 101Article in journal (Refereed)
    Abstract [en]

    Continuous glucose monitoring (CGM) has the potential to greatly improve diabetes management. The aim of this work is to show a proof-of-concept CGM device which performs minimally invasive and minimally delayed in-situ glucose sensing in the dermal interstitial fluid, combining the advantages of microneedle-based and commercially available CGM systems. The device is based on the integration of an ultra-miniaturized electrochemical sensing probe in the lumen of a single hollow microneedle, separately realized using standard silicon microfabrication methods. By placing the sensing electrodes inside the lumen facing an opening towards the dermal space, real-time measurement purely can be performed relying on molecular diffusion over a short distance. Furthermore, the device relies only on passive capillary lumen filling without the need for complex fluid extraction mechanisms. Importantly, the transdermal portion of the device is 50 times smaller than that of commercial products. This allows access to the dermis and simultaneously reduces tissue trauma, along with being virtually painless during insertion. The three-electrode enzymatic sensor alone was previously proven to have satisfactory sensitivity (1.5 nA/mM), linearity (up to 14 mM), selectivity, and long-term stability (up to 4 days) in-vitro. In this work we combine this sensor technology with microneedles for reliable insertion in forearm skin. In-vivo human tests showed the possibility to correctly and dynamically track glycaemia over time, with approximately 10 min delay with respect to capillary blood control values, in line with the expected physiological lag time. The proposed device can thus reduce discomfort and potentially enable less invasive real-time CGM in diabetic patients.

  • 139.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Laakso, Miku
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Pagliano, Simone
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Vertical Integration of Microchips by Magnetic Assembly and Edge Wire BondingIn: Article in journal (Refereed)
  • 140.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wang, Xiaojing
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Laakso, Miku
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Pagliano, Simone
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Vertical integration of microchips by magnetic assembly and edge wire bonding2020In: MICROSYSTEMS & NANOENGINEERING, ISSN 2055-7434, Vol. 6, no 1, article id 12Article in journal (Refereed)
    Abstract [en]

    The out-of-plane integration of microfabricated planar microchips into functional three-dimensional (3D) devices is a challenge in various emerging MEMS applications such as advanced biosensors and flow sensors. However, no conventional approach currently provides a versatile solution to vertically assemble sensitive or fragile microchips into a separate receiving substrate and to create electrical connections. In this study, we present a method to realize vertical magnetic-field-assisted assembly of discrete silicon microchips into a target receiving substrate and subsequent electrical contacting of the microchips by edge wire bonding, to create interconnections between the receiving substrate and the vertically oriented microchips. Vertical assembly is achieved by combining carefully designed microchip geometries for shape matching and striped patterns of the ferromagnetic material (nickel) on the backside of the microchips, enabling controlled vertical lifting directionality independently of the microchip's aspect ratio. To form electrical connections between the receiving substrate and a vertically assembled microchip, featuring standard metallic contact electrodes only on its frontside, an edge wire bonding process was developed to realize ball bonds on the top sidewall of the vertically placed microchip. The top sidewall features silicon trenches in correspondence to the frontside electrodes, which induce deformation of the free air balls and result in both mechanical ball bond fixation and around-the-edge metallic connections. The edge wire bonds are realized at room temperature and show minimal contact resistance (<0.2 Omega) and excellent mechanical robustness (>168mN in pull tests). In our approach, the microchips and the receiving substrate are independently manufactured using standard silicon micromachining processes and materials, with a subsequent heterogeneous integration of the components. Thus, this integration technology potentially enables emerging MEMS applications that require 3D out-of-plane assembly of microchips.

  • 141.
    Rivera-Lavado, Alejandro
    et al.
    Spanish Natl Geog Inst, Yebes Observ, Yebes, Spain. ivera-Lavado, Alejandro; Garcia-Munoz, Luis-Enrique; Atia Abdalmalak, Kerlos; Santamaria-Botello, Gabriel; Segovia-Vargas, Daniel.
    García-Muñoz, Luis-Enrique
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Preu, Sascha
    Abdalmalak, Kerlos
    Santamaría-Botello, Gabriel
    Segovia-Vargas, Daniel
    Räisänen, Antti V.
    Planar Lens–Based Ultra-Wideband Dielectric Rod Waveguide Antenna for Tunable THz and Sub-THz Photomixer Sources2019In: Journal of Infrared, Millimeter and Terahertz Waves, ISSN 1866-6892, E-ISSN 1866-6906, Vol. 40, no 8, p. 838-855Article in journal (Refereed)
    Abstract [en]

    In this manuscript, the use of dielectric rod waveguide antenna (DRW) with an embedded planar lens is proposed as a highly directional alternative to an electrically large hyper-hemispheric silicon lens for emission at millimeter and sub-millimeter wave frequencies. DRW antennas radiate properly if only the fundamental mode is excited to the structure. Since photomixer-based terahertz sources excite many modes, single-lobe radiation patterns are obtained only for lower frequencies of their potential working band. The use of embedded planar lenses is proposed for rectifying the wavefront phase and suppressing such higher-order modes in DRW, allowing an ultra-wideband operation.

  • 142.
    Schröder, Stephan
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. SenseAir AB.
    Towards Unconventional Applications of Wire Bonding2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents novel heterogeneous integration approaches of wire materials to fabricated and package MEMS devices by exploring unconventional applications of wire bonding technology. Wire bonding, traditionally endemic in the realm of device packaging to establish electrical die-to-package interconnections, is an attractive back-end technology, offering promising features, such as high throughput, flexibility and placement accuracy. Exploiting the advantages of state-of-the-art wire bonding technology and substitute the conventional micro welding approach with an innovative attachment concept, a generic integration platform for a multitude of wire materials is provided. This facilitates a cost-efficient and selective integration, which involves the attachment and shaping of a variety of intrinsically non-bondable wire materials. Furthermore, the selective integration of wire materials provides a simple method to generate complex suspended geometries, which circumvents the need for subsequent processing. The first part of this thesis reports of the integration of non-bondable shape memory alloy wires on wafer-level, which has led to an innovative method to fabricate micro actuators. Moreover, the integration of high performance resistive heating wires on chip-level is utilized to fabricate filament based infrared emitters, targeting non-dispersive infrared gas sensing of alcohol for automotive applications. In the second part, a series of unconventional applications of wire integration using the traditional thermo-sonic wire bonding approach is presented. A novel and low-cost nitric oxide gas sensor is realized by producing vertical bond wires featuring high aspect ratio. Next, the high placement accuracy of wire bonding tools is leveraged to integrate conductive metals cores for fabricating high aspect ratio through silicon vias. Finally, an advanced packaging approach for stress-sensitive MEMS gyroscopes is evaluated, which exclusively utilizes bond wires for realizing the die attachment.

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  • 143. Schröder, Stephan
    et al.
    Ottonello Briano, Floria
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Rödjegård, Henrik
    Bryzgalov, Maksym
    Orelund, Jonas
    Gylfason, Kristinn
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems. KTH, Superseded Departments (pre-2005), Biotechnology. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Niklaus, Frank
    KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    A large-area single-filament infrared emitter and its application in a spectroscopic ethanol gas sensing systemManuscript (preprint) (Other academic)
  • 144.
    Shafagh, Reza Zandi
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Vastesson, Alexander
    KTH.
    Guo, Weijin
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Haraldsson, Klas Tommy
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    E-Beam Nanostructuring and Direct Click Biofunctionalization of Thiol–Ene Resist2018In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 10, p. 9940-9946Article in journal (Refereed)
    Abstract [en]

    Electron beam lithography (EBL) is of major importance for ultraminiaturized biohybrid system fabrication, as it allows combining biomolecular patterning and mechanical structure definition on the nanoscale. Existing methods are limited by multistep biomolecule immobilization procedures, harsh processing conditions that are harmful to sensitive biomolecules, or the structural properties of the resulting protein monolayers or hydrogel-based resists. This work introduces a thiol-ene EBL resist with chemically reactive thiol groups on its native surface that allow the direct and selective "click" immobilization of biomolecules under benign processing conditions. We constructed EBL structured features of size down to 20 nm, and direct functionalized the nanostructures with a sandwich of biotin and streptavidin. The facile combination of polymer nanostructuring with biomolecule immobilization enables mechanically robust biohybrid components of interest for nanoscale biomedical, electronic, photonic, and robotic applications.

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  • 145.
    Shah, Umer
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Gomez Torrent, Adrian
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Ultra-Compact Micromachined Beam-Steering Antenna Front-End for High-Resolution Sub-Terahertz Radar2019In: 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), IEEE, 2019, article id 8874392Conference paper (Refereed)
    Abstract [en]

    This paper reports on an ultra-compact sub-THz frequency based beam-steering radar antenna front-end implementation utilizing a micromachined parallel-plate waveguide based leaky wave antenna. At a size of only 24 × 24 × 0.9 mm 3 , the beam-steering front-end antenna has a 28 dBi gain and a 45° field of view for scanning over 220-300 GHz. As compared to a theoretical range resolution of 6.8 mm, a range resolution of 1.2 cm was experimentally verified for 2.5 cm large targets separated by 8°. Furthermore, this paper shows a signal processing technique for frequency-steerable antennas which achieves high angular target separation by splitting the measurement frequency range into sub-sections to isolate similar slant range close-proximity targets into different frequency spaces.

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  • 146.
    Shah, Umer
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    A Very High Isolation (>50 dB) and Low Insertion Loss (<0.55 dB) 140-220 GHz MEMSWaveguide Switch2018Conference paper (Refereed)
    Abstract [en]

    This paper presents for the first time a very high isolation, low insertion loss MEMS waveguide single-pole singlethrow(SPST) switch operating in the 140-220 GHz frequency band. The high isolation is achieved by stacking threeMEMS chips, two of which contains MEMS-reconfigurable surface to block/unblock the signal in the waveguide. Thisdoubles the isolation and has little impact on the insertion loss and virtually no influence on the bandwidth. Themeasurement results of the prototype switch shows 50 to 60 dB isolation in the blocking state and 0.40 to 0.55 dBinsertion loss in the non-blocking state for the whole waveguide band. Additional measurements with reference chipshave shown that the MEMS reconfigurable surfaces of the two switch chips together contribute only to 0.1 to 0.3 dBinsertion loss. The switch bandwidth is limited only by the waveguide cut-off and not by the switch technology itself.

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  • 147. Shi, X.
    et al.
    Huang, Z.
    Laakso, Miku
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Sliz, R.
    Fabritius, T.
    Somani, M.
    Nyo, T.
    Wang, X.
    Zhang, M.
    Wang, G.
    Kömi, J.
    Huttula, M.
    Cao, W.
    Quantitative assessment of structural and compositional colors induced by femtosecond laser: A case study on 301LN stainless steel surface2019In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 484, p. 655-662Article in journal (Refereed)
    Abstract [en]

    The topic of durable coloration and passivation of metal surfaces using state-of-the-art techniques has gained enormous attention and devotion with unremitting efforts of researchers worldwide. Although femtosecond laser marking has been performed on many metals, the related coloration mechanisms are mainly referred to structural colors produced by the interaction of visible light with periodic surface structures. Yet, general quantitative determination of the resulting colors and their origins remain elusive. In this work, we realized quantitative separations of structural colors and compositional pigmentary colors on 301LN austenitic stainless steel surfaces that were treated by femtosecond laser machining. The overall color information was extracted from surface reflectance, with structural color given by numerical simulations, and oxide compositions by chemical state analysis. It was shown that the laser-induced apparent colors of 301LN steel surfaces were combinations of structural and compositional colorations, with the former dominating the angular response and the latter setting up the brownish bases. In addition to the quantification of colors, the analysis method in this work may be useful for the generation and specification of tailored color palettes for practical coloration on metal surfaces by femtosecond laser marking.

  • 148. Shi, Xinying
    et al.
    Huang, Zhongjia
    Laakso, Miku
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Niklaus, Frank
    Sliz, Rafal
    Fabritius, Tapio
    Somani, Mahesh
    Nyo, Tun
    Wang, Xiao
    Zhang, Meng
    Wang, Gang
    Kömi, Jukka
    Huttula, Marko
    Cao, Wei
    Corrigendum to "Quantitative assessment of structural and compositional colors induced by femtosecond laser: A case study on 301LN stainless steel surface" [Appl. Surf. Sci. 484 (2019) 655-662]2020In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 504, article id 144583Article in journal (Other academic)
  • 149. Shin, Su Ryon
    et al.
    Migliori, Bianca
    Miccoli, Beatrice
    Li, Yi-Chen
    Mostafalu, Pooria
    Seo, Jungmok
    Mandla, Serena
    Enrico, Alessandro
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Harvard Medical School, United States.
    Antona, Silvia
    Sabarish, Ram
    Zheng, Ting
    Pirrami, Lorenzo
    Zhang, Kaizhen
    Zhang, Yu Shrike
    Wan, Kai-tak
    Demarchi, Danilo
    Dokmeci, Mehmet R.
    Khademhosseini, Ali
    Electrically Driven Microengineered Bioinspired Soft Robots2018In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 30, no 10, article id 1704189Article in journal (Refereed)
    Abstract [en]

    To create life-like movements, living muscle actuator technologies have borrowed inspiration from biomimetic concepts in developing bioinspired robots. Here, the development of a bioinspired soft robotics system, with integrated self-actuating cardiac muscles on a hierarchically structured scaffold with flexible gold microelectrodes is reported. Inspired by the movement of living organisms, a batoid-fish-shaped substrate is designed and reported, which is composed of two micropatterned hydrogel layers. The first layer is a poly(ethylene glycol) hydrogel substrate, which provides a mechanically stable structure for the robot, followed by a layer of gelatin methacryloyl embedded with carbon nanotubes, which serves as a cell culture substrate, to create the actuation component for the soft body robot. In addition, flexible Au microelectrodes are embedded into the biomimetic scaffold, which not only enhance the mechanical integrity of the device, but also increase its electrical conductivity. After culturing and maturation of cardiomyocytes on the biomimetic scaffold, they show excellent myofiber organization and provide self-actuating motions aligned with the direction of the contractile force of the cells. The Au microelectrodes placed below the cell layer further provide localized electrical stimulation and control of the beating behavior of the bioinspired soft robot.

  • 150.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Demchenko, Petr
    ITMO University.
    Gomon, Daniel
    ITMO University.
    Lioubtchenko, Dmitri V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Khodzitsky, Mikhail
    ITMO University.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Optically controlled dielectric properties of single-walled carbon nanotubes for terahertz wave applications2018In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 10, no 26, p. 12291-12296Article in journal (Refereed)
    Abstract [en]

    Materials with tunable dielectric properties are valuable for a wide range of electronic devices, but are often lossy at terahertz frequencies. Here we experimentally report the tuning of the dielectric properties of single-walled carbon nanotubes under light illumination. The effect is demonstrated by measurements of impedance variations at low frequency as well as complex dielectric constant variations in the wide frequency range of 0.1-1 THz by time domain spectroscopy. We show that the dielectric constant is significantly modified for varying light intensities. The effect is also practically applied to phase shifters based on dielectric rod waveguides, loaded with carbon nanotube layers. The carbon nanotubes are used as tunable impedance surface controlled by light illumination, in the frequency range of 75-500 GHz. These results suggest that the effect of dielectric constant tuning with light, accompanied by low transmission losses of the carbon nanotube layer in such an ultra-wide band, may open up new directions for the design and fabrication of novel Terahertz and optoelectronic devices.

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