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  • 101.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    MEMS for medical technology applications2007In: MEMS Adaptive Optics / [ed] Olivier, S.S., Bifano T.G., Kubby J.A., 2007, Vol. 6467, p. 46513-46513Conference paper (Refereed)
    Abstract [en]

    This paper gives an in-depth description of two recent projects at the Royal Institute of Technology (KTH) which utilize MEMS and microsystem technology for realization of components intended for specific applications in medical technology and diagnostic instrumentation. By novel use of the DRIE fabrication technology we have developed side-opened out-of-plane silicon microneedles intended for use in transdermal drug delivery applications. The side opening reduces clogging probability during penetration into the skin and increases the up-take area of the liquid in the tissue. These microneedles offer about 200 mu m deep and pain-free skin penetration. We have been able to combine the microneedle chip with an electrically and heat controlled liquid actuator device where expandable microspheres are used to push doses of drug liquids into the skin. The entire unit is made of low cost materials in the form of a square one cm-sized patch. Finally, the design, fabrication and evaluation of an integrated miniaturized Quartz Crystal Microbalance (QCM) based "electronic nose" microsystem for detection of narcotics is described. The work integrates a novel environment-to-chip sample interface with the sensor element. The choice of multifunctional materials and the geometric features of a four-component microsystem allow a functional integration of a QCM crystal, electrical contacts, fluidic contacts and a sample interface in a single system with minimal assembly effort, a potential for low-cost manufacturing, and a few orders of magnitude reduced in system size (12*12*4 mm) and weight compared to commercially available instruments. The sensor chip was successfully used it for the detection of 200 ng of narcotics sample.

  • 102.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Rydholm, Susanna
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Andersson, Helene
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Cultivation of COS7-cells using extracellular matrix in 3D microfluidic surface enlarged structure2005In: Micro Total Analysis Systems 2004, 2005, no 297, p. 261-263Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel method to cultivate cells in a controlled 3D surface enlarged micro-environment. The 3D environment is achieved by insertion of a gel-like extracellular matrix (ECM) mixed with cells into a micromachined silicon fluid structure. Shrinking of the gel enables further flow through the channel. Due to the structure design the shrinking is non-uniform, which results in an increased surface area. With the proposed design cells are alive and viable after 72 h of incubation within the chip.

  • 103.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Rydholm, Susanna
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Andersson, Helene
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Three dimensional asymmetric microenvironment for cell biological studies2005In: Proceedings of µTAS 2005 Conference, 2005, p. 915-917Conference paper (Refereed)
    Abstract [en]

    We report on a method for three-dimensional cultivation of cells in a microstructured asymmetric environment. In the system an asymmetric environment is created by using diffusion through a gel of extra cellular matrix proteins surrounded by microfluidic flow channels. Individual cells embedded in the gel react on the concentration gradient. The system has been evaluated both for diffusion properties and based on the cellular response.

  • 104.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Rydholm, Susanna
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Andersson, Helene
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    A concept for miniaturized 3-D cell culture using an extracellular matrix gel2005In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 26, no 24, p. 4751-4758Article in journal (Refereed)
    Abstract [en]

    This paper presents a novel method to embed, anchor, and cultivate cells in a controlled 3-D flow-through microenvironment. This is realized using an etched silicon pillar flow chamber filled with extracellular matrix (ECM) gel mixed with cells. At 4 degrees C, while in liquid form, ECM gel is mixed with cells and injected into the chamber. Raising the temperature to 37 degrees C results in a gel, with cells embedded. The silicon pillars both stabilize and increase the surface to volume ratio of the gel. During polymerization the gel shrinks, thus creating channels, which enables perfusion through the chip. The pillars increase the mechanical stability of the gel permitting high surface flow rates without surface modifications. Within the structure cells were still viable and proliferating after 6 days of cultivation. Our method thus makes it possible to perform medium- to long-term cultivation of cells in a controlled 3-D environment. This concept opens possibilities to perform studies of cells in a more physiological environment compared to traditional 2-D cultures on flat substrates.

  • 105.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Rydholm, Susanna
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Andersson Svahn, Helene
    KTH, School of Biotechnology (BIO), Nano Biotechnology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Three dimensional asymmetric microenvironment for cell biologigal studies2005In: Proceedings Micro Total Analysis Systems (muTAS) 2005, 2005Conference paper (Refereed)
  • 106.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Rydholm, Susanna
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Liebmann, Thomas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Andersson-Svahn, Helene
    KTH, School of Biotechnology (BIO), Nano Biotechnology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    A microfluidic device for parallel 3-D cell cultures in asymmetric environments2007In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 28, no 24, p. 4705-4712Article in journal (Refereed)
    Abstract [en]

    We demonstrate a concept for how a miniaturized 3-D cell culture in biological extracellular matrix (ECM) or synthetic gels bridges the gap between organ-tissue culture and traditional 2-D cultures. A microfluidic device for 3-D cell culture including microgradient environments has been designed, fabricated, and successfully evaluated. In the presented system stable diffusion gradients can be generated by application of two parallel fluid flows with different composition against opposite sides of a gel plug with embedded cello. Culture for up to two weeks was performed showing cells still viable and proliferating. The cell tracer dye calcein was used to verify gradient formation as the fluorescence intensity in exposed cells was proportional to the position in the chamber. Cellular response to an applied stimulus was demonstrated by use of an adenosine triphosphate gradient where the onset of a stimulated intracellular calcium release also depended on cell position.

  • 107.
    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.

  • 108.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Rönnholm, David
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Fast narcotics and explosives detection using a microfluidic sample interface2005Conference paper (Refereed)
    Abstract [en]

    We introduce a novel method and system for fast detection of dust- and vapour-based narcotics and explosives traces. A micro fluidic vapour-to-liquid adsorption interface was built-in to an existing electronic nose instrument, reducing the detection time, machine size, weight, and cost. The system was successfully tested with 50 ng cocaine samples rendering 15 Hz frequency shifts and with 100 ng heroine samples rendering 50 Hz frequency shifts. Also the gravity invariance of the open liquid interface was successfully tested with the interface mounted up side down as well as vertically. The detection time was reduced to half of the time needed in commercial systems.

  • 109.
    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
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Månsson, Per
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    A miniaturised QCM-based integrated electronic nose system2007Conference paper (Other academic)
  • 110.
    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.

  • 111.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Fast Narcotics Detection with a Microfluidic Sample Interface2006In: Microsystems Technology Workshop, 2006Conference paper (Other academic)
  • 112.
    Frisk, Thomas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Fast Narcotics Detection With a Microfluidic Sample Interface2006In: Medicinteknikdagarna, 2006Conference paper (Other academic)
  • 113.
    Gey, Laurent
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Amberg, Gustav
    KTH, School of Engineering Sciences (SCI), Mechanics, Physicochemical Fluid Mechanics.
    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).
    STUDY OF THE FLIGHT OF SMALL LIQUID DROPLETS THROUGH A THIN LIQUID FILM FOR PICOLITRE LIQUID TRANSFER2006In: 19th IEEE International Conference on Micro Electro Mechanical Systems (IEEE MEMS 2006), New York: IEEE conference proceedings, 2006, p. 24-27Conference paper (Refereed)
    Abstract [en]

    We introduce and successfully demonstrate a novel method and system for subsequent dispensing, mixing and ejecting of picolitre liquid samples in a single step. The system consists of a free liquid film, suspended in a frame and positioned in front of a droplet dispenser. In this study we tested and modelled the flight of liquid droplets, ejected from an inkjet print head, through a suspended liquid film. Model and experiment are in accordance.

  • 114. Giannone, Domenico
    et al.
    Kazmierczak, Andrzej
    Dortu, Fabian
    Vivien, Laurent
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    High Performance Multichannel Photonic Biochip Sensors for Future Point of Care Diagnostics: an Overview on Two EU-Sponsored Projects2010In: SPIE Proc. 7715 BIOPHOTONICS - PHOTONIC SOLUTIONS FOR BETTER HEALTH CARE II / [ed] Jürgen Popp; Wolfgang Drexler; Valery V. Tuchin; Dennis L. Matthews, 2010, Vol. 7715, p. 77150U-1-77150U-12Conference paper (Refereed)
    Abstract [en]

    We present here research work on two optical biosensors which have been developed within two separate European projects (6(th) and 7(th) EU Framework Programmes). The biosensors are based on the idea of a disposable biochip, integrating photonics and microfluidics, optically interrogated by a multichannel interrogation platform. The objective is to develop versatile tools, suitable for performing screening tests at Point of Care or for example, at schools or in the field. The two projects explore different options in terms of optical design and different materials. While SABIO used Si(3)N(4)/SiO(2) ring resonators structures, P3SENS aims at the use of photonic crystal devices based on polymers, potentially a much more economical option. We discuss both approaches to show how they enable high sensitivity and multiple channel detection. The medium term objective is to develop a new detection system that has low cost and is portable but at the same time offering high sensitivity, selectivity and multiparametric detection from a sample containing various components (e. g. blood, serum, saliva, etc.). Most biological sensing devices already present on the market suffer from limitations in multichannel operation capability (either the detection of multiple analytes indicating a given pathology or the simultaneous detection of multiple pathologies). In other words, the number of different analytes that can be detected on a single chip is very limited. This limitation is a main issue addressed by the two projects. The excessive cost per test of conventional bio sensing devices is a second issue that is addressed.

  • 115. Gkotsis, P.
    et al.
    Kirby, P. B.
    Saharil, F.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Thin film crystal growth template removal: Application to stress reduction in lead zirconate titanate microstructures2007In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, no 16Article in journal (Refereed)
    Abstract [en]

    A key issue for the design and reliability of microdevices is process related; residual stresses in the thin films from which they are composed, especially for sol-gel deposited Pb (Zr-x, Ti1- x) O-3 ceramics, where use of Pt as a template layer, though essential for the nucleation of the perovskite phase, results in structures with high levels of stress largely fixed by the thermal expansion coefficient mismatch between Pt and Si. Here a technique for the elimination of this stress is presented, involving the use of adhesive wafer bonding and bulk micromachining procedures to remove the Pt layer following the Pb (Zr-x, Ti1-x)O-3 deposition.

  • 116.
    Gkotsis, P.
    et al.
    Cranfield University, UK.
    Leighton, G.
    Cranfield University, UK.
    Bhattacharyya, D.
    Cranfield University, UK.
    Wright, R.V
    Cranfield University, UK.
    Zhu, M.
    Cranfield University, UK.
    Kirby, P.B.
    Cranfield University, UK.
    Saharil, Farizah
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Göran, Stemme
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Crystal growth template removal: application to stress reduction in PZT microstructures2007In: Proc. International Symposium on Integrated Ferroelectrics 2007, 2007Conference paper (Refereed)
  • 117.
    Gradin, Henrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Heterogeneous Integration of Shape Memory Alloysfor High-Performance Microvalves2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents methods for fabricating MicroElectroMechanical System (MEMS) actuators and high-flow gas microvalves using wafer-level integration of Shape Memory Alloys (SMAs) in the form of wires and sheets.

    The work output per volume of SMA actuators exceeds that of other microactuation mechanisms, such as electrostatic, magnetic and piezoelectric actuation, by more than an order of magnitude, making SMA actuators highly promising for applications requiring high forces and large displacements. The use of SMAs in MEMS has so far been limited, partially due to a lack of cost efficient and reliable wafer-level integration approaches. This thesis presents new methods for wafer-level integration of nickel-titanium SMA sheets and wires. For SMA sheets, a technique for the integration of patterned SMA sheets to silicon wafers using gold-silicon eutectic bonding is demonstrated. A method for selective release of gold-silicon eutectically bonded microstructures by localized electrochemical etching, is also presented. For SMA wires, alignment and placement of NiTi wires is demonstrated forboth a manual approach, using specially built wire frame tools, and a semiautomatic approach, using a commercially available wire bonder. Methods for fixing wires to wafers using either polymers, nickel electroplating or mechanical silicon clamps are also shown. Nickel electroplating offers the most promising permanent fixing technique, since both a strong mechanical and good electrical connection to the wire is achieved during the same process step. Resistively heated microactuators are also fabricated by integrating prestrained SMA wires onto silicon cantilevers. These microactuators exhibit displacements that are among the highest yet reported. The actuators also feature a relatively low power consumption and high reliability during longterm cycling.

    New designs for gas microvalves are presented and valves using both SMA sheets and SMA wires for actuation are fabricated. The SMA-sheet microvalve exhibits a pneumatic performance per footprint area, three times higher than that of previous microvalves. The SMA-wire-actuated microvalve also allows control of high gas flows and in addition, offers benefits of lowvoltage actuation and low overall power consumption.

  • 118.
    Gradin, Henrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Braun, Stefan
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    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).
    Localized removal of the Au-Si eutectic bonding layer for the selective release of microstructures2009In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 19, no 10, p. 105014-105023Article in journal (Refereed)
    Abstract [en]

    This paper presents and investigates a novel technique for the footprint and thickness-independent selective release of Au–Si eutectically bonded microstructures through the localized removal of their eutectic bond interface. The technique is based on the electrochemical removal of the gold in the eutectic layer and the selectivity is provided by patterning the eutectic layer and by proper electrical connection or isolation of the areas to be etched or removed, respectively. The gold removal results in a porous silicon layer, acting similar to standard etch holes in a subsequent sacrificial release etching. The paper presents the principle and the design requirements of the technique. First test devices were fabricated and the method successfully demonstrated. Furthermore, the paper investigates the release mechanism and the effects of different gold layouts on both the eutectic bonding and the release procedure.

  • 119.
    Gradin, Henrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Braun, Stefan
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Wijngaart, Wouter van der
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    A WAFER-LEVEL, HETEROGENEOUSLY INTEGRATED, HIGH FLOW SMA-SILICON GAS MICROVALVE2011In: 16th IEEE International Conference on Solid-State Sensors, Actuators and Microsystems (IEEE TRANSDUCERS 2011), NEW YORK, NY: IEEE conference proceedings, 2011, p. 1781-1784Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel gas microvalve design in which a flow control gate is opened by the pneumatic pressure and closed by a SMA actuator, allowing large flow control. The microvalves were fabricated using a novel wafer-level Au-Si eutectic bonding process for TiNi to silicon integration. The resulting microvalves demonstrate a record pneumatic performance per footprint area; a microvalve of only 1×3.3 mm2 footprint successfully controls 3000 sccm at a pressure drop of 130 kPa.

  • 120.
    Gradin, Henrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Braun, Stefan
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Wijngaart, Wouter van der
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    SMA Microvalves for Very Large Gas Flow Control Manufactured Using Wafer-Level Eutectic Bonding2012In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 59, no 12, p. 4895-4906Article in journal (Refereed)
    Abstract [en]

    This paper presents a novel gas microvalve design concept, in which a flow control gate is opened by a pneumatic pressure and closed by a shape memory alloy actuator, allowing large flow control. Two different design variations were fabricated using a novel wafer-level Au-Si eutectic bonding process for TiNi to silicon integration. The resulting microvalves demonstrate a record pneumatic performance per footprint area; a microvalve with a footprint of only 1 x 3.3 mm(2) successfully controls a flow difference of 3100 sccm at a pressure drop of 70 kPa using a power of 0.35 W.

  • 121.
    Gradin, Henrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Braun, Stefan
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Sterner, Mikael
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    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).
    SELECTIVE ELECTROCHEMICAL RELEASE ETCHING OF EUTECTICALLY BONDED MICROSTRUCTURES2009In: 15th IEEE International Conference on Solid-State Sensors, Actuators and Microsystems (IEEE TRANSDUCERS 2009): 15th International Conference on Solid-State Sensors, IEEE conference proceedings, 2009, p. 743-746Conference paper (Refereed)
    Abstract [en]

    TThis paper reports on the successful demonstration of a novel microfabrication method in which eutectic gold bonded microstructures are selectively electrochemically release etched. This method offers several advantages: both a strong permanent bond and a temporary bond is achieved on the same die, the footprint of the temporary bonded structures is allowed to be larger than the footprint of the permanently bonded structures and the used etchants provide a larger process compatibility than the etchants of other release etch methods. Eutectically bonded 350 mum wide silicon structures were fully released after 1 hour of electrochemical etching followed by 1.5 hours wet etching of the TiW adhesion layer.

  • 122.
    Gradin, Henrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Clausi, Donato
    Braun, Stefan
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Peirs, Jan
    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).
    Reynaerts, Dominiek
    A low-power high-flow shape memory alloy wire gas microvalve2012In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 22, no 7, p. 1-10Article in journal (Refereed)
    Abstract [en]

    In this paper the use of shape memory alloy (SMA) wire actuators for high gas flow control is investigated. A theoretical model for effective gas flow control is presented and gate microvalve prototypes are fabricated. The SMA wire actuator demonstrates the robust flow control of more than 1600 sccm at a pressure drop of 200 kPa. The valve can be successfully switched at over 10 Hz and at an actuation power of 90 mW. Compared to the current state-of-the-art high-flow microvalves, the proposed solution benefits from a low-voltage actuator with low overall power consumption. This paper demonstrate that SMA wire actuators are well suited for high-pressurehigh-flow applications.

  • 123.
    Gudmundsson, J. T.
    et al.
    KTH, Superseded Departments, Solid Mechanics.
    Alami, J.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Bohlmark, J.
    Helmersson, U.
    Plasma Dynamics in an Unipolar Pulsed Magnetron Sputtering Discharge2004Conference paper (Refereed)
  • 124.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Nanophotonic biosensors for point of care diagnostics2011Conference paper (Refereed)
  • 125.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Agustsson, J. S.
    Olafsson, S.
    Meyvantsson, I.
    Johnsen, K.
    Gudmundsson, J. T.
    Ultra-thin Lattice Matched Cr_xMo_1-x/MgO Multilayers2004Conference paper (Refereed)
    Abstract
  • 126.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Antelius, Mikael
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    An apodized surface grating coupler enabling the fabrication of silicon photonic nanowire sensor circuits in one lithography step2011In: Proceedings IEEE International Conference on Solid-State Sensors, Actuators,and Microsystems (Transducers), Beijing, China: IEEE , 2011, p. 1539-1541Conference paper (Other academic)
    Abstract [en]

    We present the design, fabrication, and experimental characterization of a silicon surface grating coupler that enables the creation of complete photonic nanowire sensor circuits in a single lithography step on a standard SOI wafer. This advance is achieved without sacrifices in the coupling efficiency through the use of an apodization algorithm that tunes the width of each gap and bar in the grating. This design optimization provides a high light coupling efficiency and a low back reflection with a grating etched fully through the SOI device layer. We experimentally demonstrate a coupling efficiency of 35% on a standard SOI substrate at a wavelength of 1536 nm, and show that with an optimized buried oxide (BOX) thickness, a coupling efficiency of 72% could be achieved.

  • 127.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Kazmierczak, Andrzej
    Dortu, Fabian
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Vivien, Laurent
    Barrios, Carlos A.
    Wijngaart, Wouter van der
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Athermal Optical Slot-Waveguides for Temperature Insensitive Biosensing2010Conference paper (Other academic)
  • 128.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Kazmierczak, Andrzej
    Dortu, Fabian
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Vivien, Laurent
    Ronan, Gerry
    Barrios, Carlos A.
    Wijngaart, Wouter van der
    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 packaged optical slot-waveguide ring resonator sensor array for multiplex assays in Labs-on-Chip2010Conference paper (Refereed)
  • 129.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Kazmierczak, Andrzej
    Dortu, Fabian
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Vivien, Laurent
    Ronan, Gerry
    Barrios, Carlos A.
    Wijngaart, Wouter van der
    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 packaged optical slot-waveguide ring resonator sensor array for multiplex assays in Labs-on-Chip2010In: 8th Micronano System Workshop, 2010Conference paper (Other academic)
  • 130.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Kazmierczak, Andzej
    Dortu, Fabian
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Vivien, Laurent
    Ronan, Gerry
    Barrios, Carlos A.
    Wijngaart, Wouter van der
    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 packaged optical slot-waveguide ring resonator sensor array for multiplex assays in labs-on-chip2009In: Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, Chemical and Biological Microsystems Society , 2009, p. 2004-2006Conference paper (Refereed)
    Abstract [en]

    We present the design, fabrication, and characterization of a packaged array of individually addressable slot-waveguide ring resonator sensors in a compact cartridge for sensitive, label-free, multiplex assays. The novel use of a dual surfaceenergy adhesive film enables simple generic packaging method for multiple sensors in a single cartridge. The use of optical slot-waveguides, and drift compensation by on-chip light splitting to reference sensors, gives the best refractive-index limit of detection reported for planar ring resonator sensors.

  • 131.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Fischer, Andreas C.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Gunnar Malm, B. Gunnar
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Radamson, Henry H.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Belova, Lyubov M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Niklaus, Frank
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Process considerations for layer-by-layer 3D patterning of silicon, using ion implantation, silicon deposition, and selective silicon etching2012In: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. 30, no 6, p. 06FF05-Article in journal (Refereed)
    Abstract [en]

    The authors study suitable process parameters, and the resulting pattern formation, in additive layer-by-layer fabrication of arbitrarily shaped three-dimensional (3D) silicon (Si) micro- and nanostructures. The layer-by-layer fabrication process investigated is based on alternating steps of chemical vapor deposition of Si and local implantation of gallium ions by focused ion beam writing. In a final step, the defined 3D structures are formed by etching the Si in potassium hydroxide, where the ion implantation provides the etching selectivity.

  • 132.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Mola Romero, Albert
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Reducing the temperature sensitivity of SOI waveguide-based biosensors2012In: Silicon Photonics and Photonic Integrated Circuits III / [ed] Vivien, L; Honkanen, SK; Pavesi, L; Pelli, S, SPIE - International Society for Optical Engineering, 2012, Vol. 8431, p. 84310-84310Conference paper (Refereed)
    Abstract [en]

    Label-free photonic biosensors fabricated on silicon-on-insulator (SOI) can provide compact size, high evanescent field strength at the silicon waveguide surface, and volume fabrication potential. However, due to the large thermo optic coefficient of water-based biosamples, the sensors are temperature-sensitive. Consequently, active temperature control is usually used. However, for low cost applications, active temperature control is often not feasible. Here, we use the opposite polarity of the thermo-optic coefficients of silicon and water to demonstrate a photonic slot waveguide with a distribution of power between sample and silicon that aims to give athermal operation in water. Based on simulations, we made three waveguide designs close to the athermal point, and asymmetric integrated Mach- Zehnder interferometers for their characterization. The devices were fabricated on SOI with a 220 nm device layer and 2 ï¿œm buried oxide, by electron beam lithography of hydrogen silsesquioxane (HSQ) resist, and etching in a Cl2/HBr/O2/He plasma. With Cargile 50350 fused silica matching oil as top cladding, the group index of the three guides varies from 1.9 to 2.8 at 1550 nm. The temperature sensitivity of the devices varied from -70 to -160 pm/K under the same conditions. A temperature sensitivity of -2 pm/K is projected with water as top cladding.

  • 133.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Sanchez, Benito
    Griol, Amadeu
    Barrios, Carlos A.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Banuls, Maria José
    Gonzalez-Pedro, Victoria
    Maquieira, Angel
    Holgado, Miguel
    Casquel, Rafael
    Hill, Daniel
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Optical slot-waveguide micro-ring resonators for biosensing2008Conference paper (Other academic)
  • 134.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Sanchez, Benito
    Griol, Amadeu
    Barrios, Carlos A.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Banuls, Maria José
    Gonzalez-Pedro, Victoria
    Maquieira, Angel
    Holgado, Miguel
    Casquel, Rafael
    Hill, Daniel
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Robust hybridization of nanostructured buried integrated optical waveguide systems with on-chip fluid handling for chemical analysis2008In: Micro Total Analysis Systems (muTAS), 2008, p. 399-401Conference paper (Refereed)
  • 135.
    Gylfason, Kristinn Björgvin
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Integrated Optical Slot-Waveguide Ring Resonator Sensor Arrays for Lab-on-Chip Applications2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis treats the development of an integrated optical sensor array. The sensors are slot-waveguide ring resonators, integrated with on-chip surface grating couplers and light splitters, for alignment tolerant, real-time, refractive index sensing, and label-free biosensing. The work includes: the design of components and system layouts, the development of fabrication methods, the fabrication of sensor chips, the characterization of the chips, and the development of physical system models for accurate extraction of resonance wavelengths in measured spectra.

    The main scientific achievements include: The evaluation of a novel type of nano-structured optical waveguide for biochemical sensing. The realization of an array of such slot-waveguide sensors, integrated with microfluidic sample handling, for multiplex assays. The first study of the thermal behavior of slot-waveguide sensors and the discovery of unique temperature compensation capabilities.

    From an application perspective, the use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, the fabrication sequence avoids polishing of individual chips, and thus ensures that the cost benefits of silicon batch micro-fabrication can be leveraged in mass production.

    The high sensitivity of the slot waveguide resonators, combined with on-chip referencing and physical modeling, yields low limits of detection. The obtained volume refractive index detection limit of 5 × 10−6 refractive index units (RIU), and the surface mass density detection limit of 0.9 pg/mm2, shows that performance comparable to that of commercial non-integrated surface plasmon resonance sensors, made from bulk optical components, canbe achieved in a compact cartridge.

  • 136.
    Gylfason, Kristinn
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Kazmierczak, Andrzej
    Dortu, Fabian
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Vivien, Laurent
    Barrios, Carlos Angulo
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    On-chip temperature compensation in an integrated slot-waveguide ring resonator refractive index sensor array2010In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 18, no 4, p. 3226-3237Article in journal (Refereed)
    Abstract [en]

    We present an experimental study of an integrated slot-waveguide refractive index sensor array fabricated in silicon nitride on silica. We study the temperature dependence of the slot-waveguide ring resonator sensors and find that they show a low temperature dependence of -16.6 pm/K, while at the same time a large refractive index sensitivity of 240 nm per refractive index unit. Furthermore, by using on-chip temperature referencing, a differential temperature sensitivity of only 0.3 pm/K is obtained, without individual sensor calibration. This low value indicates good sensor-to-sensor repeatability, thus enabling use in highly parallel chemical assays. We demonstrate refractive index measurements during temperature drift and show a detection limit of 8.8 x 10(-6) refractive index units in a 7 K temperature operating window, without external temperature control. Finally, we suggest the possibility of athermal slot-waveguide sensor design.

  • 137.
    Haasl, Sjoerd
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Assembly of microsystems for optical and fluidic applications2005Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    This thesis addresses assembly issues encountered in optical and fluidic microsystem applications.

    In optics, the first subject concerns the active alignment of components in optical fibersystems. A solution for reducing the cost of optical component assembly while retaining submicron accuracy is to integrate the alignment mechanism onto the optical substrate. A polymer V-shaped actuator is presented that can carry the weight of the large components - on a micromechanical scale - and that can generate movement with six degrees of freedom.

    The second subject in optics is the CMOS-compatible fabrication of monocrystalline silicon micromirror arrays that are intended to serve as CMOS-controlled high-quality spatial light modulators in maskless microlithography systems. A wafer-level assembly method is presented that is based on adhesive wafer bonding whereby a monocrystalline layer is transferred onto a substrate wafer in a CMOS-compatible process without needing bond alignment.

    In fluidics, a hybrid assembly method is introduced that combines two separately micromachined structures to create hotwire anemometers that protrude from a surface with minimum interference with the air flow. The assembled sensor enables one to make accurate time-resolved measurements of the wall shear stress, a quantity that has previously been hard to measure with high time resolution. Also in the field of hotwire anemometers, a method using a hotwire anemometer array is presented for measuring the mass flow, temperature and composition of a gas in a duct.

    In biochemistry, a bio-analysis chip is presented. Single nucleotide polymorphism scoring is performed using dynamic allele-specific hybridization (DASH). Using monolayers of beads, multiplexing based on single-bead analysis is achieved at heating rates more than 20 times faster than conventional DASH provides.

    Space and material e±ciency in packaging are the focus of the other two projects in fluidics. The first introduces an assembly based on layering conductive adhesives for the fabrication of miniature polymer electrolyte membrane fuel cells. The fuel cells made with this low-cost approach perform among the best of their type to date. The second project concerns a new cross-flow microvalve concept. Intended as a step towards the mass production of large-flow I/P converters, the silicon footprint area is minimized by an out-of-plane moving gate and in-plane, half-open pneumatic channels.

  • 138.
    Haasl, Sjoerd
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Braun, Stefan
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Ridgeway, Anthony S.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Sadoon, Samir
    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).
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Out-of-Plane Knife-Gate Microvalves for Controlling Large Gas Flows2006In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 15, no 5, p. 1281-1288Article in journal (Refereed)
    Abstract [en]

    This paper considers design issues for microvalves for large gas flow control. It introduces out-of-plane knife-gate microvalves as a novel design concept and a proportional microvalve concept for pressure control applications. The design of three different actuator-gate configurations and first prototypes are presented. The first valve prototypes feature thermal silicon-aluminum bimorph actuators and the pressure-flow performance per chip area of the demonstrator valve presented is greatly increased using out-of-plane actuation and an out-of-plane orifice. The characterization of the actuators and of the pressure-flow performance is presented. The prototype valve allows for a flow change of Delta Q = 3.4 standard liters per minute (SLPM) at a pressure change of Delta P = 95 kPa (P-in = 196.3 kPa, P-out = 101.3 kPa) on an active chip area of only 2.3 x 3.7 mm(2).

  • 139.
    Haasl, Sjoerd
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Griss, Patrick
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Kälvesten, Edvard
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Robust, large-deflection, in-plane thermal polymer V-shaped actuatorsManuscript (preprint) (Other academic)
  • 140.
    Haasl, Sjoerd
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Mucha, Dirk
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Chernoray, Valery
    Thermo and Fluid Dynamics Department, Chalmers University of Technology.
    Ebefors, Thorbjörn
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Enoksson, Peter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Löfdahl, Lennart
    Thermo and Fluid Dynamics Department, Chalmers University of Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Hybrid-mounted micromachined aluminum hotwires for wall shear-stress measurements2005In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 14, no 2, p. 254-260Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a micromachined metal hotwire anemometer sensor for use in wall shear-stress measurements. We describe its design and fabrication. A novel hybrid assembly method has been developed to make it possible to measure close to the surface without contacting leads interfering with the flow. Experimental results illustrate the behavior and characteristics of this sensor.

  • 141. Haasl, Sjoerd
    et al.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Physical Sensors: Flow sensors2008In: Comprehensive Microsystems / [ed] Gianchandani, Yogesh; Tabata, Osamu; Zappe, Hans, Oxford: Elsevier Science , 2008Chapter in book (Other academic)
  • 142. Haj Hosseini, Neda
    et al.
    Rusu, Cristina
    Haasl, Sjoerd
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Krozer, Anatol
    Enoksson, Peter
    Study of molecularly imprinted polymers as synthetic receptors for biochemical sensors2006In: Proceedings Eurosensors XX, Göteborg, Sweden, 2006, Vol. I, p. 428-9Conference paper (Refereed)
  • 143.
    Hansson, Jonas
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Karlsson, J. Mikael
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Wijngaart, Wouter van der
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Russom, Aman
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Inertial Particle Focusing In Parallel Microfluidic Channels For High-Throughput Filtration2011In: 16th International  Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS), 2011, IEEE conference proceedings, 2011, p. 1777-1780Conference paper (Refereed)
    Abstract [en]

    In this study, we introduce inertial microfluidics in straight, parallel channels for high-throughput particle filtration. We show that particles flowing through low aspect ratio rectangular microchannels can be focused into four particle streams, distributed at the centers of each wall face, or into two particle streams, at the centers of the longest channel walls, depending on the particles' size. For high-throughput filtration, we fabricated scalable, single inlet and two outlet, parallel channel microdevices, using a high-density 3D microfluidic PDMS channel manufacturing technology, in a design that allows for easy integration with other downstream on-chip functions we recently described. We demonstrate filtration of 24 μm particles from a suspension mixture in a microdevice with four parallel channels. The filtration efficiency at a non-optimized flow rate of 0.8 ml/min was 82%.

  • 144.
    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.

  • 145. Hill, Daniel
    et al.
    Sanchez, Benito
    Griol, Amadeu
    Maire, Guillaume
    Dortu, Fabian
    Vivien, Laurent
    Stragier, Anne-Sophie
    Marris-Morini, Delphine
    Cassan, Eric
    Kaźmierczak, Andrzej
    Giannone, Domenico
    Gylfason, Kristinn
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Bañuls, María José
    González-Pedro, Victoria
    Maquieira, A.
    Barrios, Carlos A.
    Holgado, M.
    Casquel, R.
    Ultrahigh Sensitivity Slot-Waveguide Biosensor on a Highly Integrated Chip for Simultaneous Diagnosis of Multiple Diseases2008In: 2008 IEEE/LEOS INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS, 2008, p. 52-53Conference paper (Refereed)
    Abstract [en]

    We review some recent photonic related developments from the FP6-IST-SABIO project (026554) such as a demonstration of label-free optical biosensing with slot-waveguides and tolerance analysis of high efficiency silicon nitride surface grating couplers.

  • 146.
    Hill, Daniel
    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).
    Gylfason, Kristinn
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Carlborg, Fredrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Karlsson, J. Mikael
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Sohlström, Hans B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Russom, Aman
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Claes, T.
    Bienstman, P.
    Kazmierczak, A.
    Dortu, F.
    Banuls Polo, M. J.
    Maquieira, A.
    Kresbach, G. M.
    Vivien, L.
    Popplewell, J.
    Ronan, G.
    Barrios, C. A.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Microfluidic and Transducer Technologies for Lab on a Chip Applications2010In: 2010 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), IEEE conference proceedings, 2010, p. 305-307Conference paper (Refereed)
    Abstract [en]

    Point-of-care diagnostic devices typically require six distinct qualities: they must deliver at least the same sensitivity and selectivity, and for a cost per assay no greater than that of today's central lab technologies, deliver results in a short period of time (<15 min at GP; <2h in hospital), be portable or at least small in scale, and require no or extremely little sample preparation. State-of-the-art devices deliver information of several markers in the same measurement.

  • 147.
    Hill, Daniel
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Toccafondo, Veronica
    Garcia-Rupérez, Jaime
    Griol, Amadeu
    Garcia-Castelló, Javier
    Krüger, Asger C.
    Kristensen, Martin
    Claes, Tom
    Gironès-Molera, Jordi
    Vos, Katrien De
    Schacht, Ed
    Baets, Roel
    Bienstman, Peter
    A highly integrated optical sensor for point of care label free identification of pathogenic bacteria strains and their antibiotic resistance2010Conference paper (Other academic)
  • 148.
    Jacksén, Johan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Analytical Chemistry.
    Frisk, Thomas
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Redeby, Theres
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Analytical Chemistry.
    Parmar, Varun
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Emmer, Åsa
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Analytical Chemistry.
    Off-line integration of CE and MALDI-MS using a closed-open-closed microchannel system2007In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 28, no 14, p. 2458-2465Article in journal (Refereed)
    Abstract [en]

    In this work, a new technique for off-line hyphenation between CE and MALDI-MS is presented. Two closed fused-silica capillaries were connected via a silicon chip comprising an open microcanal. The EOF in the system was evaluated using mesityloxide or leucine-enkephalin as a sample and with a running buffer that rendered the analyte neutrally charged. Comparison was made between the EOF in a closed system (first capillary solely included in the electrical circuit) and in a closed-open system (first capillary and microcanal included in the electrical circuit). It was concluded that the experimental values of the EOF agreed with the theory. The influence of the capillary outer diameter on the peak dispersion was investigated using a closed-open-closed system (first capillary, microcanal and second capillary included in the electrical circuit). It was clearly seen that a capillary with 375 mu m od induced considerably higher peak dispersion than a 150 mu m od capillary, due to a larger liquid dead volume in the connection between the first capillary outlet and the microcanal. Mass spectrometric analysis has also been performed following CE separation runs in a closed-open-closed system with cytochrome c and lysozyme as model proteins. It was demonstrated that a signal distribution profile of the separated analytes could be recorded over a 30 mm long microcanal.

  • 149.
    Jaouen, Frédéric
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Haasl, Sjoerd
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Lundblad, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Adhesive copper films for an air-breathing polymer electrolyte fuel cell2005In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 144, no 1, p. 113-121Article in journal (Refereed)
    Abstract [en]

    A design for an air-breathing and passive polymer electrolyte fuel cell is presented. Such a type of fuel cell is in general promising for portable electronics. In the present design, the anode current collector is made of a thin copper foil. The foil is provided with an adhesive and conductive coating, which firstly tightens the hydrogen compartment without mask or clamping pressure, and secondly secures a good electronic contact between the anode backing and the current collector. The cathode comprises a backing, a gold-plated stainless steel mesh and a current collector cut out from a printed circuit board. Three geometries for the cathode current collector were evaluated. Single cells with an active area of 2 cm(2) yielded a peak power of 250-300 MW cm(-2) with air and pure H-2 in a complete passive mode except for the controlled flow of H-2. The cells' response was investigated in steady state and transient modes.

  • 150.
    Kaelvesten, Edvard
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Melvas, Patrik
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Miniaturized pressure sensor2001Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    An entirely surface micromachined free hanging strain-gauge pressure sensor is disclosed. The sensing element consists of a 80 mum long H-shaped double ended supported force transducing beam ( 16 ). The beam is located beneath and at one end attached to a square polysilicon diaphragm ( 14 ) and at the other end to the cavity edge. The sensor according to the invention enables a combination of high pressure sensitivity and miniature chip size as well as good environmental isolation. The pressure sensitivity for the sensor with a H-shaped force transducing beam, 0.4 mum thick was found to be 5 muV/V/mmHg.

1234567 101 - 150 of 375
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