Change search
Refine search result
12 1 - 50 of 99
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Ahmadian, Afshin
    et al.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    AnderssonSvahn, Helene
    KTH, School of Biotechnology (BIO), Nano Biotechnology (closed 20130101). KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Massively parallel sequencing platforms using lab on a chip technologies2011In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 11, no 16, p. 2653-2655Article in journal (Refereed)
  • 2.
    Andersson, Helene
    et al.
    KTH, Superseded Departments, Biotechnology.
    van den Berg, A.
    Microfabrication and microfluidics for tissue engineering: state of the art and future opportunities2004In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 4, no 2, p. 98-103Article, review/survey (Refereed)
    Abstract [en]

    An introductory overview of the use of microfluidic devices for tissue engineering is presented. After a brief description of the background of tissue engineering, different application areas of microfluidic devices are examined. Among these are methods for patterning cells, topographical control over cells and tissues, and bioreactors. Examples where microfluidic devices have been employed are presented such as basal lamina, vascular tissue, liver, bone, cartilage and neurons. It is concluded that until today, microfluidic devices have not been used extensively in tissue engineering. Major contributions are expected in two areas. The first is growth of complex tissue, where microfluidic structures ensure a steady blood supply, thereby circumventing the well-known problem of providing larger tissue structures with a continuous flow of oxygen and nutrition, and withdrawal of waste products. The second, and probably more important function of microfluidics, combined with micro/nanotechnology, lies in the development of in vitro physiological systems for studying fundamental biological phenomena.

  • 3.
    Andersson, Helene
    et al.
    KTH, School of Biotechnology (BIO), Nano Biotechnology (closed 20130101).
    van den Berg, Albert
    KTH.
    Where are the biologists?: A series of mini-reviews covering new trends in fundamental and applied research, and potential applications of miniaturised technologies2006In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 6, no 4, p. 467-470Article in journal (Refereed)
  • 4.
    Andersson Svahn, Helene
    et al.
    KTH, School of Biotechnology (BIO), Proteomics (closed 20130101). University of Twente, Netherlands .
    Van Den Berg, A.
    Single cells or large populations?2007In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 7, no 5, p. 544-546Article in journal (Refereed)
  • 5.
    Antypas, H.
    et al.
    Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, Stockholm, Sweden..
    Veses-Garcia, M.
    Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, Stockholm, Sweden..
    Weibull, Emelie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Svahn Andersson, Helene
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Nano Biotechnology.
    Richter-Dahlfors, A.
    Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, Stockholm, Sweden..
    A universal platform for selection and high-resolution phenotypic screening of bacterial mutants using the nanowell slide2018In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 18, no 12, p. 1767-1777Article in journal (Refereed)
    Abstract [en]

    The Petri dish and microtiter plate are the golden standard for selection and screening of bacteria in microbiological research. To improve on the limited resolution and throughput of these methods, we developed a universal, user-friendly platform for selection and high-resolution phenotypic screening based on the nanowell slide. This miniaturized platform has an optimal ratio between throughput and assay complexity, holding 672 nanowells of 500 nl each. As monoclonality is essential in bacterial genetics, we used FACS to inoculate each nanowell with a single bacterium in 15 min. We further extended the protocol to select and sort only bacteria of interest from a mixed culture. We demonstrated this by isolating single transposon mutants generated by a custom-made transposon with dual selection for GFP fluorescence and kanamycin resistance. Optical compatibility of the nanowell slide enabled phenotypic screening of sorted mutants by spectrophotometric recording during incubation. By processing the absorbance data with our custom algorithm, a phenotypic screen for growth-associated mutations was performed. Alternatively, by processing fluorescence data, we detected metabolism-associated mutations, exemplified by a screen for -galactosidase activity. Besides spectrophotometry, optical compatibility enabled us to perform microscopic analysis directly in the nanowells to screen for mutants with altered morphologies. Despite the miniaturized format, easy transition from nano- to macroscale cultures allowed retrieval of bacterial mutants for downstream genetic analysis, demonstrated here by a cloning-free single-primer PCR protocol. Taken together, our FACS-linked nanowell slide replaces manual selection of mutants on agar plates, and enables combined selection and phenotypic screening in a one-step process. The versatility of the nanowell slide, and the modular workflow built on mainstream technologies, makes our universal platform widely applicable in microbiological research.

  • 6. Armbrecht, L.
    et al.
    Dincer, C.
    Kling, A.
    Horak, Josef
    KTH, School of Biotechnology (BIO), Protein Technology. University of Freiburg, Germany.
    Kieninger, J.
    Urban, G.
    Self-assembled magnetic bead chains for sensitivity enhancement of microfluidic electrochemical biosensor platforms2015In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 15, no 22, p. 4314-4321Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a novel approach to enhance the sensitivity of microfluidic biosensor platforms with self-assembled magnetic bead chains. An adjustable, more than 5-fold sensitivity enhancement is achieved by introducing a magnetic field gradient along a microfluidic channel by means of a soft-magnetic lattice with a 350 mu m spacing. The alternating magnetic field induces the self-assembly of the magnetic beads in chains or clusters and thus improves the perfusion and active contact between the analyte and the beads. The soft-magnetic lattices can be applied independent of the channel geometry or chip material to any microfluidic biosensing platform. At the same time, the bead-based approach achieves chip reusability and shortened measurement times. The bead chain properties and the maximum flow velocity for bead retention were validated by optical microscopy in a glass capillary. The magnetic actuation system was successfully validated with a biotin-streptavidin model assay on a low-cost electrochemical microfluidic chip, fabricated by dry-film photoresist technology (DFR). Labelling with glucose oxidase (GOx) permits rapid electrochemical detection of enzymatically produced H2O2.

  • 7.
    Banerjee, Indradumna
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Aralaguppe, S. G.
    Karolinska Inst, Dept Lab Med, Div Clin Microbiol, Stockholm, Sweden..
    Lapins, Noa
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Zhang, W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science. Karolinska Inst, Dept Lab Med, Div Clin Microbiol, Stockholm, Sweden..
    Kazemzadeh, Amin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Sönnerborg, A.
    Karolinska Inst, Dept Lab Med, Div Clin Microbiol, Stockholm, Sweden..
    Neogi, Ujjwal
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science. Karolinska Inst, Dept Lab Med, Div Clin Microbiol, Stockholm, Sweden..
    Russom, Aman
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Microfluidic centrifugation assisted precipitation based DNA quantification2019In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 19, no 9, p. 1657-1664Article in journal (Refereed)
    Abstract [en]

    Nucleic acid amplification methods are increasingly being used to detect trace quantities of DNA in samples for various diagnostic applications. However, quantifying the amount of DNA from such methods often requires time consuming purification, washing or labeling steps. Here, we report a novel microfluidic centrifugation assisted precipitation (mu CAP) method for single-step DNA quantification. The method is based on formation of a visible precipitate, which can be quantified, when an intercalating dye (GelRed) is added to the DNA sample and centrifuged for a few seconds. We describe the mechanism leading to the precipitation phenomenon. We utilize centrifugal microfluidics to precisely control the formation of the visible and quantifiable mass. Using a standard CMOS sensor for imaging, we report a detection limit of 45 ng mu l(-1). Furthermore, using an integrated lab-on-DVD platform we recently developed, the detection limit is lowered to 10 ng mu l(-1), which is comparable to those of current commercially available instruments for DNA quantification. As a proof of principle, we demonstrate the quantification of LAMP products for a HIV-1B type genome containing plasmid on the lab-on-DVD platform. The simple DNA quantification system could facilitate advanced point of care molecular diagnostics.

  • 8.
    Barkefors, Irmeli
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Thorslund, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kreuger, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    A fluidic device to study directional angiogenesis in complex tissue and organ culture models2009In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 9, no 4, p. 529-535Article in journal (Refereed)
    Abstract [en]

    Many signals that induce angiogenesis have been identified; however, it is still not clear how these signals interact to shape the vascular system. We have developed a fluidic device for generation of molecular gradients in 3-dimensional cultures of complex tissues and organs in order to create an assay for precise induction and guidance of growing blood vessels. The device features a centrally placed culture chamber, flanked by channels attached to a perfusion system used to generate gradients. A separate network of vacuum channels permits reversible attachment of the device to a flat surface. We show that the fluidic device can be used to create growth factor gradients that induce directional angiogenesis in embryonic mouse kidneys and in clusters of differentiating stem cells. These results demonstrate that the device can be used to accurately manipulate complex morphogenetic processes with a high degree of experimental control.

  • 9.
    Barnkob, Rune
    et al.
    Tech Univ Denmark, Lyngby, Denmark .
    Iranmanesh, Ida
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Wiklund, Martin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Bruus, Henrik
    Tech Univ Denmark, Lyngby, Denmark .
    Measuring acoustic energy density in microchannel acoustophoresis using a simple and rapid light-intensity method2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 13, p. 2337-2344Article in journal (Refereed)
    Abstract [en]

    We present a simple and rapid method for measuring the acoustic energy density in microchannel acoustophoresis based on light-intensity measurements of a suspension of particles. The method relies on the assumption that each particle in the suspension undergoes single-particle acoustophoresis. It is validated by the single-particle tracking method, and we show by proper re-scaling that the re-scaled light intensity plotted versus re-scaled time falls on a universal curve. The method allows for analysis of moderate-resolution images in the concentration range encountered in typical experiments, and it is an attractive alternative to particle tracking and particle image velocimetry for quantifying acoustophoretic performance in microchannels.

  • 10.
    Bergström, Gunnar
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, The Institute of Technology.
    Christoffersson, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, Faculty of Science & Engineering.
    Schwanke, Kristin
    Hannover Medical School, Leibniz Research Laboratories for Biotechnology and Artificial Organs -LEBAO-, Hannover, Germany.
    Zweigerdt, Robert
    Hannover Medical School, Leibniz Research Laboratories for Biotechnology and Artificial Organs -LEBAO-, Hannover, Germany.
    Mandenius, Carl-Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, The Institute of Technology.
    Stem cell derived in vivo-like human cardiac bodies in a microfluidic device for toxicity testing by beating frequency imaging2015In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 15, no 15, p. 3242-3249Article in journal (Refereed)
    Abstract [en]

    Beating in vivo-like human cardiac bodies (CBs) were used in a microfluidic device for testing cardiotoxicity. The CBs, cardiomyocyte cell clusters derived from induced pluripotent stem cells, exhibited typical structural and functional properties of the native human myocardium. The CBs were captured in niches along a perfusion channel in the device. Video imaging was utilized for automatic monitoring of the beating frequency of each individual CB. The device allowed assessment of cardiotoxic effects on the 3D clustered cardiomyocytes from the drug substances doxorubicin, verapamil and quinidine. Beating frequency data recorded over a period of 6 hours are presented and compared to literature data. The results indicate that this microfluidic setup with imaging of CB characteristics provides a new opportunity for label-free, non-invasive investigation of toxic effects in a 3D microenvironment.

  • 11.
    Bergström, Gunnar
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, The Institute of Technology.
    Nilsson, K.
    Percell Biolytica AB, Åstorp, Sweden.
    Mandenius, Carl-Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, The Institute of Technology.
    Robinson, Nathaniel D
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Macroporous microcarriers for introducing cells into a microfluidic chip2014In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, no 18, p. 3502-3504Article in journal (Refereed)
    Abstract [en]

    Macroporous gelatin beads (CultiSpher™ microcarriers) provide a convenient method for rapidly and reliably introducing cells cultured ex situ into a microfluidic device, where the spheres create a 3D environment for continued cell proliferation. We demonstrate the usefulness of this technique with a proof-of-concept viability analysis of cardiac cells after treatment with doxorubicin. © 2014 the Partner Organisations.

  • 12. Bruus, Henrik
    et al.
    Dual, Jürg
    Hawkes, Jeremy
    Hill, Martyn
    Laurell, Thomas
    Nilsson, Johan
    Radel, Stefan
    Wiklund, Martin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Forthcoming lab on a chip tutorial series on acoustofluidics: Acoustofluidics - Exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation2011In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 11, no 21, p. 3579-3580Article in journal (Other academic)
  • 13.
    Carlborg, Carl Fredrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Gylfason, Kristinn Björgvin
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Kazmierczak, Andrzej
    Dortu, Fabian
    Banuls Polo, Maria Jose
    Maquieira Catala, Angel
    Kresbach, Gerhard
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Moh, Thomas
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Vivien, Laurent
    Popplewell, Jon
    Ronan, Gerry
    Barrios, Carlos Angulo
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    A packaged optical slot-waveguide ring resonator sensor array for multiplex label-free assays in labs-on-chips2010In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, no 3, p. 281-290Article in journal (Refereed)
    Abstract [en]

    We present the design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing. Multiplexing not only enables high throughput, but also provides reference channels for drift compensation and control experiments. Our use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, our novel use of a dual surface-energy adhesive film to bond a hard plastic shell directly to the PDMS microfluidic network allows for fast and leak-tight assembly of compact cartridges with tightly spaced fluidic interconnects. The high sensitivity of the slot-waveguide resonators, combined with on-chip referencing and physical modelling, yields a volume refractive index detection limit of 5 x 10(-6) refractive index units (RIUs) and a surface mass density detection limit of 0.9 pg mm(-2), to our knowledge the best reported values for integrated planar ring resonators.

  • 14.
    Carlborg, Carl Fredrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Öberg, Kim
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Beyond PDMS: off-stoichiometry thiol–ene (OSTE) based soft lithography for rapid prototyping of microfluidic devices2011In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 11, no 18, p. 3136-3147Article in journal (Refereed)
    Abstract [en]

    In this article we introduce a novel polymer platform based on off-stoichiometry thiol–enes (OSTEs), aiming to bridge the gap between research prototyping and commercial production of microfluidic devices. The polymers are based on the versatile UV-curable thiol–ene chemistry but takes advantage of off-stoichiometry ratios to enable important features for a prototyping system, such as one-step surface modifications, tuneable mechanical properties and leakage free sealing through direct UV-bonding. The platform exhibits many similarities with PDMS, such as rapid prototyping and uncomplicated processing but can at the same time mirror the mechanical and chemical properties of both PDMS as well as commercial grade thermoplastics. The OSTE-prepolymer can be cast using standard SU-8 on silicon masters and a table-top UV-lamp, the surface modifications are precisely grafted using a stencil mask and the bonding requires only a single UV-exposure. To illustrate the potential of the material we demonstrate key concepts important in microfluidic chip fabrication such as patterned surface modifications for hydrophobic stops, pneumatic valves using UV-lamination of stiff and rubbery materials as well as micromachining of chip-to-world connectors in the OSTE-materials.

  • 15.
    Chang, Tsung-Yao
    et al.
    Massachusetts Institute of Technology, USA.
    Pardo-Martin, Carlos
    Massachusetts Institute of Technology, USA.
    Allalou, Amin
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Wählby, Carolina
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Yanik, Mehmet Fatih
    Massachusetts Institute of Technology, USA.
    Fully automated cellular-resolution vertebrate screening platform with parallel animal processing2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 4, p. 711-716Article in journal (Refereed)
    Abstract [en]

    The zebrafish larva is an optically-transparent vertebrate model with complex organs that is widelyused to study genetics, developmental biology, and to model various human diseases. In this article, wepresent a set of novel technologies that significantly increase the throughput and capabilities of ourpreviously described vertebrate automated screening technology (VAST). We developed a robustmulti-thread system that can simultaneously process multiple animals. System throughput is limitedonly by the image acquisition speed rather than by the fluidic or mechanical processes. We developedimage recognition algorithms that fully automate manipulation of animals, including orienting andpositioning regions of interest within the microscope’s field of view. We also identified the optimalcapillary materials for high-resolution, distortion-free, low-background imaging of zebrafish larvae.

  • 16.
    Cheng, Shi
    et al.
    Radio Hardware Division at Ericsson.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Microfluidic electronics2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 16, p. 2782-2791Article in journal (Refereed)
    Abstract [en]

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e. g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  • 17.
    Cheng, Shi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microwave and Terahertz Technology.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Microfluidic stretchable RF electronics2010In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, no 23, p. 3227-3234Article in journal (Refereed)
    Abstract [en]

    Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e. g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

  • 18.
    Christakou, Athanasia
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Ohlin, Mathias
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Önfelt, Björn
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics. Karolinska Inst, Dept Microbiol Tumor & Cell Biol, Stockholm, Sweden.
    Wiklund, Martin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Ultrasonic three-dimensional on-chip cell culture for dynamic studies of tumor immune surveillance by natural killer cells2015In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 15, no 15, p. 3222-31Article in journal (Refereed)
    Abstract [en]

    We demonstrate a simple method for three-dimensional (3D) cell culture controlled by ultrasonic standing waves in a multi-well microplate. The method gently arranges cells in a suspension into a single aggregate in each well of the microplate and, by this, nucleates 3D tissue-like cell growth for culture times between two and seven days. The microplate device is compatible with both high-resolution optical microscopy and maintenance in a standard cell incubator. The result is a scaffold- and coating-free method for 3D cell culture that can be used for controlling the cellular architecture, as well as the cellular and molecular composition of the microenvironment in and around the formed cell structures. We demonstrate the parallel production of one hundred synthetic 3D solid tumors comprising up to thousands of human hepatocellular carcinoma (HCC) HepG2 cells, we characterize the tumor structure by high-resolution optical microscopy, and we monitor the functional behavior of natural killer (NK) cells migrating, docking and interacting with the tumor model during culture. Our results show that the method can be used for determining the collective ability of a given number of NK cells to defeat a solid tumor having a certain size, shape and composition. The ultrasound-based method itself is generic and can meet any demand from applications where it is advantageous to monitor cell culture from production to analysis of 3D tissue or tumor models using microscopy in one single microplate device.

  • 19.
    Comina, German
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Suska, Anke
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Low cost lab-on-a-chip prototyping with a consumer grade 3D printer2014In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, no 16, p. 2978-2982Article in journal (Refereed)
    Abstract [en]

    Versatile prototyping of 3D printed lab-on-a-chip devices, supporting different forms of sample delivery, transport, functionalization and readout, is demonstrated with a consumer grade printer, which centralizes all critical fabrication tasks. Devices cost 0.57US$ and are demonstrated in chemical sensing and micromixing examples, which exploit established principles from reference technologies.

  • 20.
    Comina, German
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Suska, Anke
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    PDMS lab-on-a-chip fabrication using 3D printed templates2014In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, no 2, p. 424-430Article in journal (Refereed)
    Abstract [en]

    The fabrication of conventional PDMS on glass lab-on-a-chip (LOC) devices, using templates printed with a commercial (2299 US$) micro-stereo lithography 3D printer, is demonstrated. Printed templates replace clean room and photolithographic fabrication resources and deliver resolutions of 50 mu m, and up to 10 mu m in localized hindrances, whereas the templates are smooth enough to allow direct transfer and proper sealing to glass substrates. 3D printed templates accommodate multiple thicknesses, from 50 mu m up to several mm within the same template, with no additional processing cost or effort. This capability is exploited to integrate silicone tubing easily, to improve micromixer performance and to produce multilevel fluidics with simple access to independent functional surfaces, which is illustrated by time-resolved glucose detection. The templates are reusable, can be fabricated in under 20 min, with an average cost of 0.48 US$, which promotes broader access to established LOC configurations with minimal fabrication requirements, relieves LOC fabrication from design skills and provides a versatile LOC development platform.

  • 21. Corrie, S R
    et al.
    Fernando, G J P
    Crichton, M L
    Brunck, M E G
    Anderson, Chris D
    Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Dermatology and Venerology.
    Kendall, M A F
    Surface-modified microprojection arrays for intradermal biomarker capture, with low non-specific protein binding2010In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, p. 2655-2658Article in journal (Refereed)
    Abstract [en]

    Minimally invasive biosensors are of great interest for rapid detection of disease biomarkers for diagnostic screening at the point-of-care. Here we introduce a device which extracts disease-specific biomarkers directly from the upper dermis, without the needle and syringe or resource-intensive blood processing. Using antigen-specific antibodies raised in mice as a model system, we confirm the analytical specificity and sensitivity of the antibody capture and extraction in comparison to the conventional methods based on needle/syringe blood draw followed by processing and antigen-specific ELISAs.

  • 22.
    Cruz, Javier
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Graells, Tiscar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Wallden, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Inertial focusing with sub-micron resolution for separation of bacteria2019In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 19, no 7, p. 1257-1266Article in journal (Refereed)
    Abstract [en]

    In this paper, we study inertial focusing in curved channels and demonstrate the alignment of particles with diameters between 0.5 and 2.0 m, a range of biological relevance since it comprises a multitude of bacteria and organelles of eukaryotic cells. The devices offer very sensitive control over the equilibrium positions and allow two modes of operation. In the first, particles having a large variation in size are focused and concentrated together. In the second, the distribution spreads in a range of sizes achieving separation with sub-micron resolution. These systems were validated with three bacteria species (Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae) showing good alignment while maintaining the viability in all cases. The experiments also revealed that the particles follow a helicoidal trajectory to reach the equilibrium positions, similar to the fluid streamlines simulated in COMSOL, implying that these positions occupy different heights in the cross section. When the equilibrium positions move to the inner wall as the flow rate increases, they are at a similar distance from the centre than in straight channels (approximate to 0.6R), but when the equilibrium positions move to the outer wall as the flow rate increases, they are closer to the centre and the particles pass close to the inner wall to elevate their position before reaching them. These observations were used along with COMSOL simulations to explain the mechanism behind the local force balance and the migration of particles, which we believe contributes to further understanding of the phenomenon. Hopefully, this will make designing more intuitive and reduce the high pressure demands, enabling manipulation of particles much smaller than a micrometer.

  • 23.
    Dalslet, Bjarke Thomas
    et al.
    Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Lyngby, Danmark.
    Damsgaard, Christian Danvad
    Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Lyngby, Danmark.
    Donolato, Marco
    LNESS Dipartimento di Fisica, Politecnico di Milano, Como, Italien.
    Strømme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömberg, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Hansen, Mikkel Fougt
    Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Lyngby, Danmark.
    Bead magnetorelaxometry with an on-chip magnetoresistive sensor2011In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 11, no 2, p. 296-302Article in journal (Refereed)
    Abstract [en]

    Magnetorelaxometry measurements on suspensions of magnetic beads are demonstrated using a planar Hall effect sensor chip embedded in a microfluidic system. The alternating magnetic field used for magnetizing the beads is provided by the sensor bias current and the complex magnetic susceptibility spectra are recorded as the 2nd harmonic of the sensor response. The complex magnetic susceptibility signal appears when a magnetic bead suspension is injected, it scales with the bead concentration, and it follows the Cole-Cole expression for Brownian relaxation. The complex magnetic susceptibility signal resembles that from conventional magnetorelaxometry done on the same samples apart from an offset in Brownian relaxation frequency. The time dependence of the signal can be rationalized as originating from sedimented beads.

  • 24. Di Carlo, Dino
    et al.
    Huang, Yanyi
    Andersson-Svahn, Helene
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Emerging investigators: new challenges spawn new innovations2014In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, no 15, p. 2599-2600Article in journal (Refereed)
  • 25. Douagi, Anna Sjöström
    et al.
    Svahn, Helene Andersson
    KTH, School of Biotechnology (BIO), Proteomics.
    Young researchers to tackle future Grand Challenges2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 4, p. 680-683Article in journal (Other academic)
  • 26. Enger, Jonas
    et al.
    Goksör, Mattias
    Ramser, Kerstin
    Hagberg, Petter
    Hanstorp, Dag
    Optical tweezers applied to a microfluidic system2004In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 4, no 3, p. 196-200Article in journal (Refereed)
    Abstract [en]

    We will demonstrate how optical tweezers can be combined with a microfluidic system to create a versatile microlaboratory. Cells are moved between reservoirs filled with different media by means of optical tweezers. We show that the cells, on a timescale of a few seconds, can be moved from one reservoir to another without the media being dragged along with them. The system is demonstrated with an experiment where we expose E. coli bacteria to different fluorescent markers. We will also discuss how the system can be used as an advanced cell sorter. It can favorably be used to sort out a small fraction of cells from a large population, in particular when advanced microscopic techniques are required to distinguish various cells. Patterns of channels and reservoirs were generated in a computer and transferred to a mask using either a sophisticated electron beam technique or a standard laser printer. Lithographic methods were applied to create microchannels in rubber silicon (PDMS). Media were transported in the channels using electroosmotic flow. The optical system consisted of a combined confocal and epi-fluorescence microscope, dual optical tweezers and a laser scalpel.

  • 27. Eriksson, Emma
    et al.
    Enger, Jonas
    Nordlander, Bodil
    Erjavec, Nika
    Ramser, Kerstin
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Goskör, Mattias
    Hohmann, Stefan
    Nyström, Thomas
    Hanstorp, Dag
    A microfluidic system in combination with optical tweezers for analyzing rapid and reversible cytological alterations in single cells upon environmental changes2007In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 7, p. 71-76Article in journal (Refereed)
    Abstract [en]

    We report on the development of an experimental platform where epi-fluorescence microscopy and optical tweezers are combined with a microfluidic system to enable the analysis of rapid cytological responses in single cells. The microfluidic system allows two different media to be merged in a Y-shaped channel. Microscale channel dimensions ensure purely laminar flow and, as a result, an environmental gradient can be created between the two media. Optical tweezers are used to move a single trapped cell repeatedly between the different environments. The cell is monitored continuously by fluorescence microscopy during the experiment. In a first experiment on yeast (Saccharomyces cerevisiae) we observed changes in cell volume as the cell was moved between environments with different osmolarity. This demonstrated that the platform allowed analysis of cytological alterations on a time scale shorter than 0.2 s. In a second experiment we observed the spatial migration of the Yap1p transcription factor fused to GFP as a cell was moved from an environment of low to high oxidative capacity. The system is universal allowing the response to numerous environmental changes to be studied on the sub second time scale in a variety of model cells. We intend to use the platform to study how the age of cells, their progression through the cell cycle, or their genetic landscape, alter their capacity (kinetics and amplitude) to respond to environmental changes.

  • 28.
    Fatsis-Kavalopoulos, Nikos
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology. Gradientech AB, Uppsala, Sweden.
    O'Callaghan, Paul
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Xie, Beichen
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Hernández Vera, Rodrigo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Idevall Hagren, Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Kreuger, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Formation of precisely composed cancer cell clusters using a cell assembly generator (CAGE) for studying paracrine signaling at single-cell resolution2019In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 19, no 6, p. 1071-1081Article in journal (Refereed)
    Abstract [en]

    The function and behaviour of any given cell in a healthy tissue, or in a tumor, is affected by interactions with its neighboring cells. It is therefore important to create methods that allow for reconstruction of tissue niches in vitro for studies of cell-cell signaling and associated cell behaviour. To this end we created the cell assembly generator (CAGE), a microfluidic device which enables the organization of different cell types into precise cell clusters in a flow chamber compatible with high-resolution microscopy. In proof-of-concept paracrine signalling experiments, 4-cell clusters consisting of one pancreatic -cell and three breast cancer cells were formed. It has previously been established that extracellular ATP induces calcium (Ca2+) release from the endoplasmic reticulum (ER) to the cytosol before it is cleared back into the ER via sarcoplasmic/ER Ca2+ ATPase (SERCA) pumps. Here, ATP release from the -cell was stimulated by depolarization, and dynamic changes in Ca2+ levels in the adjacent cancer cells measured using imaging of the calcium indicator Fluo-4. We established that changes in the concentration of cytosolic Ca2+ in the cancer cells were proportional to the distance from the ATP-releasing -cell. Additionally, we established that the relationship between distance and cytosolic calcium changes were dependent on Ca2+-release from the ER using 5-cell clusters composed of one -cell, two untreated cancer cells and two cancer cells pretreated with Thapsigargin (to deplete the ER of Ca2+). These experiments show that the CAGE can be used to create exact cell clusters, which affords precise control for reductionist studies of cell-cell signalling and permits the formation of heterogenous cell models of specific tissue niches.

  • 29.
    Faxälv, Lars
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Chemistry.
    Bolin, Maria
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Lindahl, Tomas
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Chemistry.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Electronic control of platelet adhesion using conducting polymer microarrays2014In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, no 16, p. 3043-3049Article in journal (Refereed)
    Abstract [en]

    We hereby report a method to fabricate addressable micropatterns of e-surfaces based on the conducting polymer poly(3,4-ethylenedioxythiophene) doped with the anion tosylate (PEDOT:Tos) to gain dynamic control over the spatial distribution of platelets in vitro. With thin film processing and microfabrication techniques, patterns down to 10 mu m were produced to enable active regulation of platelet adhesion at high spatial resolution. Upon electronic addressing, both reduced and oxidized surfaces were created within the same device. This surface modulation dictates the conformation and/or orientation, rather than the concentration, of surface proteins, thus indirectly regulating the adhesion of platelets. The reduced electrode supported platelet adhesion, whereas the oxidized counterpart inhibited adhesion. PEDOT:Tos electrode fabrication is compatible with most of the classical patterning techniques used in printing as well as in the electronics industry. The first types of tools promise ultra-low-cost production of low-resolution (greater than30 mu m) electrode patterns that may combine with traditional substrates and dishes used in a classical analysis setup. Platelets play a pronounced role in cardiovascular diseases and have become an important drug target in order to prevent thrombosis. This clinical path has in turn generated a need for platelet function tests to monitor and assess platelet drug efficacy. The spatial control of platelet adherence presented here could prove valuable for blood cell separation or biosensor microarrays, e.g. in diagnostic applications where platelet function is evaluated.

  • 30.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Rönnholm, David
    Biosensor Applications Sweden AB.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    A micromachined interface for airborne sample-to-liquid transfer and its application in a biosensor system2006In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 6, no 12, p. 1504-1509Article in journal (Refereed)
    Abstract [en]

    A novel micromachined interface for airborne sample-to-liquid adsorption and droplet-to-liquid transfer was designed and fabricated. It enables a robust sheet liquid flow serving as an adsorption site. The interface was characterised for flow and pressure properties and tested successfully for the transfer/adsorption of different samples. A qualitative theoretical model of the device characteristics is presented. We also used the interface to introduce a novel method and system for fast detection of dust- and vapour-based narcotics and explosives traces. The microfluidic vapour-to-liquid adsorption interface was coupled to a set of downstream QCM sensors. The system was tested successfully, with 50 ng cocaine samples rendering 15 Hz frequency shifts and with 100 ng heroine samples rendering 50 Hz frequency shifts. Gravitation invariance of the open liquid interface was demonstrated successfully, with the interface mounted upside down as well as vertically. The detection time was reduced to half of the time needed in previous systems. Machine size, weight and cost were reduced.

  • 31.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Sandström, Niklas
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Eng, Lars
    Biosensor Applications AB, Solna.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Månsson, Per
    Biosensor Applications AB, Solna.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    An integrated QCM-based narcotics sensing microsystem2008In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 8, no 10, p. 1648-1657Article in journal (Refereed)
    Abstract [en]

    We present the design, fabrication and successful testing of a 14 x 14 x 4 mm(3) integrated electronic narcotics sensing system which consists of only four parts. The microsystem absorbs airborne narcotics molecules and performs a liquid assay using an integrated quartz crystal microbalance (QCM). A vertically conductive double-sided adhesive foil (VCAF) was used and studied as a novel material for LOC and MEMS applications and provides easy assembly, electrical contacting and liquid containment. The system was tested for measuring cocaine and ecstasy, with successful detection of amounts as small as 100 ng and 200 ng, respectively These levels are of interest in security activities in customs, prisons and by the police.

  • 32. Frykholm, K.
    et al.
    Nyberg, L. K.
    Lagerstedt, E.
    Noble, C.
    Fritzsche, J.
    Karami, N.
    Ambjornsson, T.
    Sandegren, Linus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Westerlund, F.
    Fast size-determination of intact bacterial plasmids using nanofluidic channels2015In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 15, no 13, p. 2739-2743Article in journal (Refereed)
    Abstract [en]

    We demonstrate how nanofluidic channels can be used as a tool to rapidly determine the number and sizes of plasmids in bacterial isolates. Each step can be automated at low cost, opening up opportunities for general use in microbiology labs.

  • 33.
    Frykholm, K.
    et al.
    Department of Biology and Biological Engineering, Chalmers University of Technology.
    Nyberg, L. K.
    Department of Biology and Biological Engineering, Chalmers University of Technology.
    Lagerstedt, Erik
    Department of Astronomy and Theoretical Physics, Lund University.
    Noble, C.
    Department of Astronomy and Theoretical Physics, Lund University.
    Fritzsche, J.
    Department of Applied Physics, Chalmers University of Technology.
    Karami, N.
    Department of Clinical Microbiology, Sahlgrenska University Hospital and Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy of the University of Gothenburg.
    Ambjörnsson, T.
    Department of Astronomy and Theoretical Physics, Lund University.
    Sandegren, L.
    Department of Medical Biochemistry and Microbiology, Uppsala University.
    Westerlund, F.
    Department of Biology and Biological Engineering, Chalmers University of Technology.
    Fast size-determination of intact bacterial plasmids using nanofluidic channels2015In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 15, no 13, p. 2739-2743Article in journal (Refereed)
    Abstract [en]

    We demonstrate how nanofluidic channels can be used as a tool to rapidly determine the number and sizes of plasmids in bacterial isolates. Each step can be automated at low cost, opening up opportunities for general use in microbiology labs.

  • 34.
    Gabrielsson, Erik O.
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ion diode logics for pH control2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 14, p. 2507-2513Article in journal (Refereed)
    Abstract [en]

    Electronic control over the generation, transport, and delivery of ions is useful in order to regulate reactions, functions, and processes in various chemical and biological systems. Different kinds of ion diodes and transistors that exhibit non-linear current versus voltage characteristics have been explored to generate chemical gradients and signals. Bipolar membranes (BMs) exhibit both ion current rectification and water splitting and are thus suitable as ion diodes for the regulation of pH. To date, fast switching ion diodes have been difficult to realize due to accumulation of ions inside the device structure at forward bias – charges that take a long time to deplete at reverse bias. Water splitting occurs at elevated reverse voltage bias and is a feature that renders high ion current rectification impossible. This makes integration of ion diodes in circuits difficult. Here, we report three different designs of micro-fabricated ion bipolar membrane diodes (IBMDs). The first two designs consist of single BM configurations, and are capable of either splitting water or providing high current rectification. In the third design, water-splitting BMs and a highly-rectifying BM are connected in series, thus suppressing accumulation of ions. The resulting IBMD shows less hysteresis, faster off-switching, and also a high ion current rectification ratio as compared to the single BM devices. Further, the IBMD was integrated in a diode-based AND gate, which is capable of controlling delivery of hydroxide ions into a receiving reservoir.

  • 35. Gamby, Jean
    et al.
    Rudolf, Aurore
    Abid, Mohamed
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Girault, H
    Deslouis, Claude
    Tribollet, Bernard
    Polycarbonate microchannel network with carpet of Gold NanoWires as SERS-active device2009In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 9, no 12, p. 1806-1808Article in journal (Refereed)
    Abstract [en]

    A polycarbonate (PC) microchannel network supporting gold nanowires was developed to be a SERS-active microchip. Observations of large increases in a Raman cross-section, allowed us to collect vibrational signatures which are not easily detectable by Raman techniques due to the high fluorescence level of bare PC. Compared to other SERS experiments, this study relies on the use of dielectric polymer/metal surfaces which are well defined at microscale and nanoscale levels. This device seems a promising tool for sensing the adsorption of biomolecules.

  • 36. Griss, P.
    et al.
    Andersson, Helene
    KTH, Superseded Departments, Biotechnology.
    Stemme, Göran
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Expandable microspheres for the handling of liquids2002In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 2, no 2, p. 117-120Article in journal (Refereed)
    Abstract [en]

    Two novel concepts for controlled handling of liquids in microfluidic systems are presented: a one-shot micropump and a normally open one-shot valve based on thermo-expanding Expancel microspheres. Expancel microspheres are small spherical plastic particles that, when heated, increase their volume considerably. We show that liquid volumes in the nanoliter range can be actuated against a counter pressure of at least 100 kPa and fluid flow can be inhibited in a microchannel against pressures of at least 100 kPa.

  • 37. Hadikhani, P.
    et al.
    Hashemi, S. M. H.
    Balestra, G.
    Zhu, Lailai
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, Centres, SeRC - Swedish e-Science Research Centre. Princeton University, United States.
    Modestino, M. A.
    Gallaire, F.
    Psaltis, D.
    Inertial manipulation of bubbles in rectangular microfluidic channels2018In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 18, no 7, p. 1035-1046Article in journal (Refereed)
    Abstract [en]

    Inertial microfluidics is an active field of research that deals with crossflow positioning of the suspended entities in microflows. Until now, the majority of the studies have focused on the behavior of rigid particles in order to provide guidelines for microfluidic applications such as sorting and filtering. Deformable entities such as bubbles and droplets are considered in fewer studies despite their importance in multiphase microflows. In this paper, we show that the trajectory of bubbles flowing in rectangular and square microchannels can be controlled by tuning the balance of forces acting on them. A T-junction geometry is employed to introduce bubbles into a microchannel and analyze their lateral equilibrium position in a range of Reynolds (1 < Re < 40) and capillary numbers (0.1 < Ca < 1). We find that the Reynolds number (Re), the capillary number (Ca), the diameter of the bubble (D), and the aspect ratio of the channel are the influential parameters in this phenomenon. For instance, at high Re, the flow pushes the bubble towards the wall while large Ca or D moves the bubble towards the center. Moreover, in the shallow channels, having aspect ratios higher than one, the bubble moves towards the narrower sidewalls. One important outcome of this study is that the equilibrium position of bubbles in rectangular channels is different from that of solid particles. The experimental observations are in good agreement with the performed numerical simulations and provide insights into the dynamics of bubbles in laminar flows which can be utilized in the design of flow based multiphase flow reactors.

  • 38.
    Hansson, Jonas
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hillmering, Mikael
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Leak-tight vertical membrane microvalves2016In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 16, no 8, p. 1439-1446Article in journal (Refereed)
    Abstract [en]

    Pneumatic microvalves are fundamental control components in a large range of microfluidic applications. Their key performance parameters are small size, i.e. occupying a minimum of microfluidic real estate, low flow resistance in the open state, and leak-tight closing at limited control pressures. In this work we present the successful design, realization and evaluation of the first leak-tight, vertical membrane, pneumatic microvalves. The realization of the vertical membrane microvalves is enabled by a novel dual-sided molding method for microstructuring monolithic 3D microfluidic networks in PDMS in a single step, eliminating the need for layer-to-layer alignment during bonding. We demonstrate minimum lateral device features down to 20-30 mu m in size, and vertical via density of similar to 30000 per cm(2), which provides significant gains in chip real estate compared to previously reported PDMS manufacturing methods. In contrast to horizontal membrane microvalves, there are no manufacturing restrictions on the cross-sectional geometry of the flow channel of the vertical membrane microvalves. This allows tuning the design towards lower closing pressure or lower open state flow resistance compared to those of horizontal membrane microvalves.

  • 39.
    Hansson, Jonas
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics. KTH, School of Biotechnology (BIO), Nano Biotechnology (closed 20130101).
    Karlsson, Mikael J.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Russom, Aman
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics. KTH, School of Biotechnology (BIO), Nano Biotechnology (closed 20130101).
    Inertial microfluidics in parallel channels for high-throughput applications2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 22, p. 4644-4650Article in journal (Refereed)
    Abstract [en]

    Passive particle focusing based on inertial microfluidics was recently introduced as a high-throughput alternative to active focusing methods that require an external force-field to manipulate particles. In this study, we introduce inertial microfluidics in flows through straight, multiple parallel channels. The scalable, single inlet and two outlet, parallel channel system is enabled by a novel, high-density 3D PDMS microchannel manufacturing technology, mediated via a targeted inhibition of PDMS polymerization. Using single channels, we first demonstrate how randomly distributed particles can be focused into the centre position of the channel in flows through low aspect ratio channels and can be effectively fractionated. As a proof of principle, continuous focusing and filtration of 10 μm particles from a suspension mixture using 4- and 16-parallel-channel devices with a single inlet and two outlets are demonstrated. A filtration efficiency of 95-97% was achieved at throughputs several orders of magnitude higher than previously shown for flows through straight channels. The scalable and low-footprint focusing device requiring neither external force fields nor mechanical parts to operate is readily applicable for high-throughput focusing and filtration applications as a stand-alone device or integrated with lab-on-a-chip systems.

  • 40.
    Hou, Zining
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    An, Yu
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sandegren, Linus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Time lapse investigation of antibiotic susceptibility using a microfluidic linear gradient 3D culture device2014In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, no 17, p. 3409-3418Article in journal (Refereed)
    Abstract [en]

    This study reports a novel approach to quantitatively investigate the antibacterial effect of antibiotics on bacteria using a three-dimensional microfluidic culture device. In particular, our approach is suitable for studying the pharmacodynamics effects of antibiotics on bacterial cells temporally and with a continuous range of concentrations in a single experiment. The responses of bacterial cells to a linear concentration gradient of antibiotics were observed using time-lapse photography, by encapsulating bacterial cells in an agarose-based gel located in a commercially available microfluidics chamber. This approach generates dynamic information with high resolution, in a single operation, e. g., growth curves and antibiotic pharmacodynamics, in a well-controlled environment. No pre-labelling of the cells is needed and therefore any bacterial sample can be tested in this setup. It also provides static information comparable to that of standard techniques for measuring minimum inhibitory concentration (MIC). Five antibiotics with different mechanisms were analysed against wild-type Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. The entire process, including data analysis, took 2.5-4 h and from the same analysis, high-resolution growth curves were obtained. As a proof of principle, a pharmacodynamic model of streptomycin against Salmonella Typhimurium was built based on the maximal effect model, which agreed well with the experimental results. Our approach has the potential to be a simple and flexible solution to study responding behaviours of microbial cells under different selection pressures both temporally and in a range of concentrations.

  • 41.
    Hutchison, J.
    et al.
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Haraldsson, Klas Tommy
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Good, Brian
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Sebra, Robert
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Luo, Ning
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Anseth, Kristi
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Bowman, Christopher
    Dept. of Chem. and Biol. Engineering, ECCH 111, University of Colorado.
    Robust Polymer Microfluidic Device Fabrication via Contact Liquid Photolitographic Polymerization (CLiPP)2004In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 4, no 6, p. 658-662Article in journal (Refereed)
    Abstract [en]

    Microfluidic devices are commonly fabricated in silicon or glass using micromachining technology or elastomers using soft lithography methods; however, invariable bulk material properties, limited surface modification methods and difficulty in fabricating high aspect ratio devices prevent these materials from being utilized in numerous applications and/or lead to high fabrication costs. Contact Liquid Photolithographic Polymerization (CLiPP) was developed as an alternative microfabrication approach that uniquely exploits living radical photopolymerization chemistry to facilitate surface modification of device components, fabrication of high aspect ratio structures from many different materials with numerous covalently-adhered layers and facile construction of three-dimensional devices. This contribution describes CLiPP and demonstrates unique advantages of this new technology for microfabrication of polymeric microdevices. Specifically, the procedure for fabricating devices with CLiPP is presented, the living radical photopolymerization chemistry which enables this technology is described, and examples of devices made using CLiPP are shown.

  • 42. Jeong, S. H.
    et al.
    Hagman, Anton
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    Hjort, K.
    Jobs, M.
    Sundqvist, J.
    Wu, Z.
    Liquid alloy printing of microfluidic stretchable electronics2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 22, p. 4657-4664Article in journal (Refereed)
    Abstract [en]

    Recently, microfluidic stretchable electronics has attracted great interest from academia since conductive liquids allow for larger cross-sections when stretched and hence low resistance at longer lengths. However, as a serial process it has suffered from low throughput, and a parallel processing technology is needed for more complex systems and production at low costs. In this work, we demonstrate such a technology to implement microfluidic electronics by stencil printing of a liquid alloy onto a semi-cured polydimethylsiloxane (PDMS) substrate, assembly of rigid active components, encapsulation by pouring uncured PDMS on-top and subsequent curing. The printing showed resolution of 200 μm and linear resistance increase of the liquid conductors when elongated up to 60%. No significant change of resistance was shown for a circuit with one LED after 1000 times of cycling between a 0% and an elongation of 60% every 2 s. A radio frequency identity (RFID) tag was demonstrated using the developed technology, showing that good performance could be maintained well into the radio frequency (RF) range.

  • 43.
    Jeong, Seung Hee
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hagman, Anton
    KTH, Hållfasthetslära, Stockholm.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Jobs, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Sundqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Liquid alloy printing of microfluidic stretchable electronics2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 22, no 12, p. 4657-4664Article in journal (Refereed)
    Abstract [en]

    Recently, microfluidic stretchable electronics has attracted great interest from academia since conductive liquids allow for larger cross-sections when stretched and hence low resistance at longer lengths. However, as a serial process it has suffered from low throughput, and a parallel processing technology is needed for more complex systems and production at low costs. In this work, we demonstrate such a technology to implement microfluidic electronics by stencil printing of a liquid alloy onto a semi-cured polydimethylsiloxane (PDMS) substrate, assembly of rigid active components, encapsulation by pouring uncured PDMS on-top and subsequent curing. The printing showed resolution of 200 mm and linear resistance increase of the liquid conductors when elongated up to 60%. No significant change of resistance was shown for a circuit with one LED after 1000 times of cycling between a 0% and an elongation of 60% every 2 s. A radio frequency identity (RFID) tag was demonstrated using the developed technology, showing that good performance could be maintained well into the radio frequency (RF) range.

  • 44.
    Johansson, LarsErik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    Gunnarsson, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Bijelovic, Stojanka
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Eriksson, Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    Surpi, Alessandro
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    Gothelid, Emmanuelle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Oscarsson, Sven
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    A magnetic microchip for controlled transport of attomole levels of proteins2010In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, no 5, p. 654-661Article in journal (Refereed)
    Abstract [en]

    A novel method of controlled transport of proteins immobilized on micrometre-sized magnetic beads in a lab-on-a-chip environment is presented. Bead motion is controlled by lithographically made magnetic elements forming transportation lines in combination with an applied in-plane rotating magnetic field. In this way, transport of attomole amounts of proteins is controlled with micrometre precision. Also, the activity of proteins immobilized on the beads is demonstrated by injecting antibodies into the system. A critical step in developing the method was to reduce sticking forces between beads and substrate during transportation of proteins. Charge interaction was found to be of minor importance compared to hydrophobic forces. To achieve a reliable transport of biologically active proteins, both substrate and beads were coated with polyethylene glycol (PEG) and the protein covered beads were suspended in buffer with surfactants. The described system fulfils all the important unit operations of a microfluidic platform and, as a further advantage, presents less need for microchannels and electric wiring.

  • 45. Johansson, LarsErik
    et al.
    Gunnarsson, Klas
    Bijelovic, Stojanka
    Eriksson, Kristofer
    Surpi, Alessandro
    Gothelid, Emmanuelle
    Svedlindh, Peter
    Oscarsson, Sven
    A magnetic microchip for controlled transport of attomole levels of proteins2010In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, no 5, p. 654-661Article in journal (Refereed)
  • 46.
    Johansson, Linda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Micro Structural Technology .
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Surface Acoustic Wave-induced particle sorting with node-position flexibilityIn: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189Article in journal (Refereed)
  • 47.
    Johansson, Linda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Johansson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thorslund, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Effective mixing of laminar flows at a density interface by an integrated ultrasonic transducer2009In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 9, no 2, p. 297-304Article in journal (Refereed)
    Abstract [en]

    An acoustic mixer for glass channel microfluidic systems is presented. An acoustic standing wave, perpendicular to the fluid flow, is generated by the excitation of a miniaturized piezoelectric transducer operated around 10 MHz. The transducer is fabricated into a planar printed circuit board structure, constituting the bottom channel wall, which makes the mixer simple to integrate with a wide selection of microfluidic channel designs. The mixing occurs at a fluid-fluid density interface due to the acoustic radiation force; an analytical expression is derived to qualitatively describe this phenomenon. Only a small density difference in the range of 2–5% is required to achieve 150–270% peak broadening of a fluorescent sample between sheath flows, which we use as a measure of the mixing efficiency. The mixing efficiency is measured with regard to its sensitivity to the density difference, the fluid velocity and the transducer driving frequency. Transducers at different positions along the microchannel make it possible to compare the mixing of straight versus diagonal flows across the transducer surface. We finally demonstrate enhanced chemical lysis of E. coli K12 cells in the device due to active fluid mixing.

  • 48.
    Jokilaakso, Nima
    et al.
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Salm, Eric
    Chen, Aaron
    Millet, Larry
    Guevara, Carlos Duarte
    Dorvel, Brian
    Reddy, Bobby, Jr.
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Chen, Yu
    Ji, Hongmiao
    Sooryakumar, Ratnasingham
    Bashir, Rashid
    Ultra-localized single cell electroporation using silicon nanowires2013In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 13, no 3, p. 336-339Article in journal (Refereed)
    Abstract [en]

    Analysis of cell-to-cell variation can further the understanding of intracellular processes and the role of individual cell function within a larger cell population. The ability to precisely lyse single cells can be used to release cellular components to resolve cellular heterogeneity that might be obscured when whole populations are examined. We report a method to position and lyse individual cells on silicon nanowire and nanoribbon biological field effect transistors. In this study, HT-29 cancer cells were positioned on top of transistors by manipulating magnetic beads using external magnetic fields. Ultra-rapid cell lysis was subsequently performed by applying 600-900 mV(pp) at 10 MHz for as little as 2 ms across the transistor channel and the bulk substrate. We show that the fringing electric field at the device surface disrupts the cell membrane, leading to lysis from irreversible electroporation. This methodology allows rapid and simple single cell lysis and analysis with potential applications in medical diagnostics, proteome analysis and developmental biology studies.

  • 49.
    Jonas, Hansson
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Yasuga, Hiroki
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Synthetic microfluidic paper: high surface area and high porosity polymer micropillar arrays2016In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 16, no 2, p. 298-304Article in journal (Refereed)
    Abstract [en]

    We introduce Synthetic Microfluidic Paper, a novel porous material for microfluidic applications that consists of an OSTE polymer that is photostructured in a well-controlled geometry of slanted and interlocked micropillars. We demonstrate the distinct benefits of Synthetic Microfluidic Paper over other porous microfluidic materials, such as nitrocellulose, traditional paper and straight micropillar arrays: in contrast to straight micropillar arrays, the geometry of Synthetic Microfluidic Paper was miniaturized without suffering capillary collapse during manufacturing and fluidic operation, resulting in a six-fold increased internal surface area and a three-fold increased porous fraction. Compared to commercial nitrocellulose materials for capillary assays, Synthetic Microfluidic Paper shows a wider range of capillary pumping speed and four times lower device-to-device variation. Compared to the surfaces of the other porous microfluidic materials that are modified by adsorption, Synthetic Microfluidic Paper contains free thiol groups and has been shown to be suitable for covalent surface chemistry, demonstrated here for increasing the material hydrophilicity. These results illustrate the potential of Synthetic Microfluidic Paper as a porous microfluidic material with improved performance characteristics, especially for bioassay applications such as diagnostic tests.

  • 50.
    Jonsson, C.
    et al.
    Jönsson, C., Åmic AB, Uppsala, Sweden, Biomedical Diagnostics Institute, NCSR Building, Dublin City University, Glasnevin Dublin 9, Ireland.
    Aronsson, M.
    Åmic AB, Uppsala, Sweden.
    Rundstrom, G.
    Rundström, G., Åmic AB, Uppsala, Sweden.
    Pettersson, C.
    Åmic AB, Uppsala, Sweden.
    Mendel-Hartvig, I.
    Åmic AB, Uppsala, Sweden.
    Bakker, J.
    Åmic AB, Uppsala, Sweden, Biomedical Diagnostics Institute, NCSR Building, Dublin City University, Glasnevin Dublin 9, Ireland.
    Martinsson, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    MacCraith, B.
    Biomedical Diagnostics Institute, NCSR Building, Dublin City University, Glasnevin Dublin 9, Ireland.
    Ohman, O.
    Öhman, O., Åmic AB, Uppsala, Sweden.
    Melin, J.
    Åmic AB, Uppsala, Sweden, Biomedical Diagnostics Institute, NCSR Building, Dublin City University, Glasnevin Dublin 9, Ireland.
    Silane-dextran chemistry on lateral flow polymer chips for immunoassays2008In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 8, no 7, p. 1191-1197Article in journal (Refereed)
    Abstract [en]

    The prognosis for patients suffering from cardiovascular and many other diseases can be substantially improved if diagnosed at an early stage. High performance diagnostic testing using disposable microfluidic chips can provide a platform for realizing this vision. Åmic AB (Uppsala, Sweden) has developed a new microfluidic test chip for sandwich immunoassays fabricated by injection molding of the cycloolefin-copolymer Zeonor™. A highly ordered array of micropillars within the fluidic chip distributes the sample solution by capillary action. Since wetting of the pillar array surface is the only driving force for liquid distribution precise control of the surface chemistry is crucial. In this work we demonstrate a novel protocol for surface hydrophilization and antibody immobilization on cycloolefin-copolymer test chips, based on direct silanisation of the thermoplastic substrate. Dextran is subsequently covalently coupled to amino groups, thus providing a coating with a low contact angle suitable for antibody immobilization. The contact angle of dextran coated chips is stable for at least two months, which enables production of large batches that can be stored for extended periods of time. We demonstrate the utility of the presented platform and surface chemistry in a C-reactive protein assay with a detection limit of 2.6 ng ml-1, a dynamic range of 102 and a coefficient of variance of 15%. © The Royal Society of Chemistry.

12 1 - 50 of 99
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf