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  • 101.
    Gatty, Hithesh Kumar
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A wafer-level liquid cavity integrated amperometric gas sensor with ppb-level nitric oxide gas sensitivity2015In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 10, article id 105013Article in journal (Refereed)
    Abstract [en]

    A miniaturized amperometric nitric oxide (NO) gas sensor based on wafer-level fabrication of electrodes and a liquid electrolyte chamber is reported in this paper. The sensor is able to detect NO gas concentrations of the order of parts per billion (ppb) levels and has a measured sensitivity of 0.04 nA ppb(-1) with a response time of approximately 12 s. A sufficiently high selectivity of the sensor to interfering gases such as carbon monoxide (CO) and to ammonia (NH3) makes it potentially relevant for monitoring of asthma. In addition, the sensor was characterized for electrolyte evaporation which indicated a sensor operation lifetime allowing approximately 200 measurements.

  • 102.
    Ghebru, Alexander
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Metodik för testning av styrsystem2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis, a general test methodology is created for the testing of control system for pumps. The test methodology is described with models that in a structured way help planning the testing preparation and execution. The methodology is then applied through a stepwise template for how to do the testing in practice.

    A method for optimizing the numbers of tests is presented. This method will reduce the number of test using the signals with the highest priority that are sent between the controller and pump. A calculation scheme in Excel has been created that brings out the prioritized test procedure for the tester to follow.

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  • 103.
    Glubokov, Oleksandr
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Xinghai, Zhao
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Beuerle, Bernhard
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Campion, James
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Shah, Umer
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Micromachined Multilayer Bandpass Filter at 270 GHz Using Dual-Mode Circular Cavities2017In: 2017 IEEE MTT-S International Microwave Symposium, IEEE conference proceedings, 2017, p. 1449-1452, article id 8058894Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a microfabricated fourth-order sub-THz WR-3.4 bandpass waveguide filter based on TM110 dual-mode circular-shaped cavity resonators. The filter operates at the center frequency of 270 GHz with fractional bandwidth of 1.85% and two transmission zeros are introduced in the upper and in the lower stopband using a virtual negative coupling. The microchip filter is significantly more compact than any previous dual-mode designs at comparable frequencies, occupying less than 1.5 mm2. Furthermore, in contrast to any previous micromachined filter work, due to its axially arranged interfaces it can be directly inserted between two standard WR-3.4 rectangular-waveguide flanges, which vastly improves system integration as compared to previous micromachined filters; in particular no custom-made split-block design is required. The cavities are etched in the handle layer of a silicon-on-insulator (SOI) wafer, and coupling is realized through rectangular slots fabricated in the SOI device layer. Couplings of the degenerate modes in one cavity are facilitated by means of small perturbations in the circular cavity shapes. The measured average return loss in the passband is –18 dB and worst-case return loss is –15 dB, and an insertion loss of only 1.5 dB was measured. The excellent agreement between measured and simulated data is facilitated by fabrication accuracy, design robustness and micromachined self-alignment geometries.

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  • 104.
    Glubokov, Oleksandr
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Xinghai, Zhao
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Campion, James
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Beuerle, Bernhard
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Shah, Umer
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Multilayer Micromachined Dual-Mode Elliptic Cavities Filter With Axial Feeding at 270 GHz2018Conference paper (Refereed)
    Abstract [en]

    A silicon micromachined multilayer bandpass filters using dual-mode elliptic cavities at 270 GHz is shown.The cross-coupled filter has been designed taking into accountthe side-walls non-verticality. Good agreement with simulations has been obtained for the filter. Excellent performancein terms of losses has been demonstrated.

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    fulltext
  • 105.
    Gomez-Torrent, Adrian
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Shah, Umer
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A Silicon Micromachined 220-330 GHz Turnstile Orthomode Transducer (OMT) in a Low-Loss Micromachining Fabrication Platform2018Conference paper (Refereed)
    Abstract [en]

    The work presented in this paper reports on the first wideband OMT in any frequency band implemented by micromachining. This turnstile-junction design provides full waveguide-band operation (220-330 GHz) and is the first implementation of a turnstile-OMT above 110 GHz, since very accurate fabrication is required for this topology. The measured insertion loss is below 0.5 dB and below 0.6 dB for the two polarizations, respectively, with an average measured return loss of 22 dB. Except for some spikes which still are below 30 dB, the cross-polarization is between 50 and 60 dB.

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    fulltext
  • 106.
    Gradin, Henrik
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Bushra, Sobia
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Braun, Stefan
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Wafer-level integration of NiTi shape memory alloy on silicon using Au-Si eutectic bonding2013In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 23, no 1, p. 1-14Article in journal (Refereed)
    Abstract [en]

    This paper reports on the wafer level integration of NiTi shape memory alloy (SMA) sheets with silicon substrates through Au-Si eutectic bonding. Different bond parameters, such as Au layer thicknesses and substrate surface treatments were evaluated. The amount of gold in the bond interface is the most important parameter to achieve a high bond yield; the amount can be determined by the barrier layers between the Au and Si or by the amount of Au deposition. Deposition of a gold layer of more than 1 mu m thickness before bonding gives the most promising results. Through patterning of the SMA sheet and by limiting bonding to small areas, stresses created by the thermal mismatch between Si and NiTi are reduced. With a gold layer of 1 mu m thickness and bond areas between 200 x 200 and 800 x 800 mu m(2) a high bond strength and a yield above 90% is demonstrated.

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  • 107. Grogg, Daniel
    et al.
    Ayala, Christopher L.
    Drechsler, Ute
    Sebastian, A.
    Koelmans, W. W.
    Bleiker, Simon J.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Fernandez-Bolanos, Montserrat
    Hagleitner, Christoph
    Despont, Michel
    Duerig, Urs T.
    Amorphous carbon active contact layer for reliable nanoelectromechanical switches2014In: 2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS), IEEE conference proceedings, 2014, p. 143-146Conference paper (Refereed)
    Abstract [en]

    This paper reports an amorphous carbon (a-C) contact coating for ultra-low-ower curved nanoelectromechanical (NEM) switches. a-C addresses important problems in miniaturization and low-ower operation of mechanical relays: i) the surface energy is lower than that of metals, ii) active formation of highly localized a-C conducting filaments offers a way to form nanoscale contacts, and iii) high reliability is achieved through the excellent wear properties of a-C, demonstrated in this paper with more than 100 million hot switching cycles. Finally, a full inverter using a-C contacts is fabricated to demonstrate the viability of the concept.

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  • 108. Gronicz, J.
    et al.
    Aaltonen, L.
    Chekurov, Nikolay
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Kosunen, M.
    Halonen, K.
    A 1.8 MHz MEMS-based oscillator with synchronous amplitude limiter2013In: 2013 European Conference on Circuit Theory and Design, ECCTD 2013 - Proceedings, 2013, p. 6662225-Conference paper (Refereed)
    Abstract [en]

    This paper describes the design and simulation of a MEMS-based oscillator using a synchronous amplitude limiter. The proposed solution does not require external control signals to keep the resonator drive amplitude within the desired range. In a MEMS oscillator the oscillation amplitude needs to be limited to avoid over-driving the resonator which could cause unwanted nonlinear behavior [1] or component failure. The interface electronics has been implemented and simulated in 0.35μm HV CMOS process. The resonator was fabricated using a custom rapid-prototyping process involving Focused Ion Beam masking and Cryogenic Deep Reactive Ion Etching.

  • 109. Gronicz, J.
    et al.
    Chekurov, Nikolay
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Aaltonen, L.
    Halonen, K.
    A MEMS-based oscillator with synchronous amplitude control2013In: Conf. Proc. - Conf. Ph. D. Res. Microelectron. Electron., PRIME, 2013, p. 117-120Conference paper (Refereed)
    Abstract [en]

    This paper describes the design and simulation of a MEMS-based oscillator with a silicon tuning fork as frequency selective element. The interface electronics include a synchronous amplitude control circuit that allows for precise control of oscillation amplitude. The nominal oscillation frequency is 1.8 MHz. The structure has been implemented using a 0.35 μm High Voltage CMOS process and operates with a nominal supply of 3.3V.

  • 110. Gronicz, J.
    et al.
    Chekurov, Nikolay
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems. Department of Micro and Nanosciences, Aalto University, Tietotie 3, Espoo FI-00076, Finland .
    Kosunen, M.
    Tittonen, I.
    Design and fabrication of a tuning fork shaped voltage controlled resonator for low-voltage applications with additional tuning electrodes2013In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 23, no 11Article in journal (Refereed)
    Abstract [en]

    In this work a silicon voltage controlled microelectromechanical tuning fork resonator with electrostatic actuation and separate frequency tuning electrodes is presented. The released device is fabricated using a silicon-on-insulator wafer by a two-step process involving only focused ion beam masking and cryogenic deep reactive ion etching. This process is ideal for rapid prototyping, as the time to turn a design into the final device is only a few hours. The design of the resonator is optimized to accommodate the restrictions of the fabrication process, to maximize the frequency tuning range and to minimize the biasing voltage. Separating tuning and driving electrodes enables the resonance frequency adjustment by over 70 000 ppm (f center > 1.5 MHz, quality factor Q ≈ 2000) with a tuning voltage of 29 V in an open loop mode.

  • 111.
    Guo, Maoxiang
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hernández-Neuta, Iván
    Madaboosi, Narayanan
    Nilsson, Mats
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    CROSS-MEMBRANE ELECTRICAL DETECTION OF DNA2017Conference paper (Refereed)
    Abstract [en]

    We introduce out-of-plane metallic nanowire formation on DNA templates, which are stretched through a porous membrane by applying a receding meniscus interface. We demonstrate the direct electrical detection of DNA using these gold nanowire bridges between the membrane’s opposite surfaces. Such a simple electrical readout can be extended for biosensor applications, thanks to the high specificity and multiplexing offered by Rolling Circle Amplification (RCA).

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  • 112.
    Guo, Maoxiang
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Vastesson, Alexander
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Carlborg, Carl Fredrik
    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.
    LONG-TERM STORAGE OF NANOLITRE AND PICOLITRE LIQUID VOLUMES IN POLYMER MICROFLUIDIC DEVICES2015In: the 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences (Micro TAS), The Chemical and Biological Microsystems Society , 2015, p. 1386-1388Conference paper (Refereed)
    Abstract [en]

    We introduce uncomplicated nanolitre (23 nL) and picolitre (3.5 pL) liquid volume encapsulation in Off-Stoichiometry Thiol-Ene-Epoxy polymer (OSTEmerTM322) wells using spontaneous room- temperature bonding of gold films to thiol and thioether groups present on the surface of the polymer for leak free sealing. First, we show liquid encapsulation within nL, and pL polymer wells by utilizing 100 nm thin Au-film transfer-bonding onto intermediately cured, and micropatterned OSTEmerTM322. This approach yielded 3 magnitude orders smaller liquid volume encapsulation than previously reported. Secondly, we show that encapsulated liquid can be stored for >116 h. Finally, we demonstrate encapsulated liquid release by thermopneumatic bursting. We conclude that OSTEmerTM322 is excellent for metal-film sealant integration in polymer microfluidic devices. 

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  • 113.
    Guo, Weijin
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hansson, Jonas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Capillary Pumping Independent Of Liquid Sample Viscosity2016In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827Article in journal (Refereed)
    Abstract [en]

    Capillary flow is a dominating liquid transport phenomenon on the micro- and nanoscale. As described at the beginning of the 20th century, the flow rate during imbibition of a horizontal capillary tube follows the Washburn equation, i.e. decreases over time and depends on the viscosity of the sample. This poses a problem for capillary driven systems that rely on a predictable flow rate and where the liquid viscosity is not precisely known. Here we introduce and successfully experimentally verify the first compact capillary pump design with a flow rate constant in time and independent of the liquid viscosity that can operate over an extended period of time. We also present a detailed theoretical model for gravitation independent capillary filling, which predicts the novel pump performance to within measurement error margins, and in which we, for the first time, explicitly identify gas inertia dominated flow as a fourth distinct flow regime in capillary pumping. These results are of potential interest for a multitude of applications and we expect our results to find most immediate applications within lab-on-a-chip systems and diagnostic devices.

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    viscosity
  • 114.
    Guo, Weijin
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hansson, Jonas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Capillary pumping with a constant flow rate independent of the liquid sample viscosity and surface energy2017In: Proceeding of 2017 IEEE 30th International Conference on Micro Electro Mechanical Systems (MEMS), IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    We introduce and experimentally verify a capillary pump design that, for the first time, enables autonomous pumping of sample liquid with a flow rate constant in time and independent of the sample viscosity and sample surface energy. These results are of interest for applications that rely on a predictable flow rate and where the sample fluid viscosity or surface energy are not precisely known, e.g. in capillary driven diagnostic lateral flow biosensors for urine or blood sample, where large variations exist in both viscosity and surface energy between different patient samples.

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    viscosity and surface energy
  • 115.
    Guo, Weijin
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hansson, Jonas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Viscosity Independent Paper Microfluidic Imbibition2016In: Proceedings of The 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2016, MicroTAS , 2016, p. 13-14Conference paper (Refereed)
    Abstract [en]

    This work introduces capillary flow in paper microfluidics that features a flow rate Q that is constant in time, t, and independent of the viscosity of liquid sample, μ liquid: Q≠f(t, μ liquid). Compared to conventional paper microfluidics, we enclose the paper in solid walls and add a long and narrow air vent as outlet of the capillary pump, such that the flow rate is dominated by the downstream air resistance. Therefore, the flow rate depends on the viscosity of air rather than that of liquid. This significantly decreases the dependency of lateral flow biosensors on variations of sample fluid.

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  • 116.
    Guo, Weijin
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Vilaplana, Lluisa
    IQAC-CSIC.
    Hansson, Jonas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Marco, M.-Pilar
    IQAC-CSIC.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Immunoassays on thiol-ene synthetic paper generate a superior fluorescence signal2020In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235Article in journal (Refereed)
    Abstract [en]

    The fluorescence-based detection of biological complexes on solid substrates is widely used in microarrays and lateral flow tests. Here, we investigate thiol-ene micropillar scaffold sheets (“synthetic paper”) as the solid substrate in such assays. Compared to state-of-the-art glass and nitrocellulose substrates, assays on synthetic paper provide a stronger fluorescence signal, similar or better reproducibility, lower limit of detection (LOD), and the possibility of working with lower immunoreagent concentrations. Using synthetic paper, we detected the antibiotic enrofloxacin in whole milk with a LOD of 1.64 nM, which is on par or better than the values obtained with other common tests, and much lower than the maximum level allowed by European Union regulations. The significance of these results lays in that they indicate that synthetically-derived microstructured substrate materials have the potential to improve the performance of diagnostic assays.

    The full text will be freely available from 2022-05-11 20:14
  • 117.
    Gustafsson, Linnea
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Jansson, Ronnie
    KTH, School of Biotechnology (BIO), Protein Technology.
    Hedhammar, My
    KTH, School of Biotechnology (BIO), Protein Technology.
    vad der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Controlled Formation of Spider Silk Nanowires, Localized Surface Coatings, and Sheets Using Superhydrophobic Surfaces2017Conference paper (Refereed)
    Abstract [en]

    We show how specific microfluidic manipulation of spidroin solution on superhydrophobic surfaces results in the controlled formation of spider silk nanowires, surface coatings, and sheets. Envisaged applications include biosensing, protein microarrays and cell culture.

  • 118.
    Gustafsson, Linnea
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Jansson, Ronnie
    KTH, School of Biotechnology (BIO), Protein Technology.
    Hedhammar, My
    KTH, School of Biotechnology (BIO), Protein Technology.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Structuring of Functional Spider Silk Wires, Coatings, and Sheets by Self-Assembly on Superhydrophobic Pillar Surfaces2018In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 30, no 3, article id 1704325Article in journal (Refereed)
    Abstract [en]

    Spider silk has recently become a material of high interest for a large number of biomedical applications. Previous work on structuring of silk has resulted in particles (0D), fibers (1D), films (2D), and foams, gels, capsules, or microspheres (3D). However, the manufacturing process of these structures is complex and involves posttreatment of chemicals unsuitable for biological applications. In this work, the self-assembly of recombinant spider silk on micropatterned superhydrophobic surfaces is studied. For the first time, structuring of recombinant spider silk is achieved using superhydrophobic surfaces under conditions that retain the bioactivity of the functionalized silk. By tuning the superhydrophobic surface geometry and the silk solution handling parameters, this approach allows controlled generation of silk coatings, nanowires, and sheets. The underlying mechanisms and governing parameters are discussed. It is believed that the results of this work pave the way for fabrication of silk formations for applications including vehicles for drug delivery, optical sensing, antimicrobial coatings, and cell culture scaffolds.

  • 119.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Errando-Herranz, Carlos
    Sandström, Niklas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Shafagh, Reza Zandi
    Wijngaart, Wouter van der
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Integration of polymer based microfluidics with silicon photonics for biosensing applications2015Conference paper (Other academic)
    Abstract [en]

    We present a novel integration method for packaging silicon photonic sensors with polymer microfluidics, designed to be suitable for wafer-level production. The method addresses the previously unmet manufacturing challenges of matching the microfluidic footprint area to that of the photonics, and of robust bonding of microfluidic layers to biofunctionalized surfaces. We demonstrate the fabrication, in a single step, of a microfluidic layer in the recently introduced OSTE polymer, and the subsequent unassisted dry bonding of the microfluidic layer to a grating coupled silicon photonic ring resonator sensor chip. The microfluidic layer features photopatterned through holes (vias) for optical fiber probing and fluid connections, as well as molded microchannels and tube connectors, and is manufactured and subsequently bonded to a silicon sensor chip in less than 10 minutes. Combining this new microfluidic packaging method with photonic waveguide surface gratings for light couplin g allows matching the size scale of microfluidics to that of current silicon photonic biosensors.

  • 120.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Ottonello Briano, Floria
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Quellmalz, Arne
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Method for fabrication of a suspended elongated structure by etching or dissolution through openings in a layer2019Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    A method for fabrication of a device (100) with an elongated structure (5), extending in a length direction (L) in a device layer (2) is described. The method comprises the steps of providing a planar first layer (1) on which the device layer (2) is supported, removing material in the device layer (2) to provide a first set of openings (3) through the device layer (2), and removing material from the planar first layer (1) under the elongated structure (5) through the first set of openings (3), wherein he arrangement of the first set of openings (3) is such that said support structure (4) is formed on which the elongated structure (5) is supported. The method also comprises the step of removing material from the device layer (2) to form the elongated structure (5) delimited by side surfaces (6).

  • 121.
    Gylfason, Kristinn B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Ottonello Briano, Floria
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A Sensor Device and a Method of Detecting a Component in Gas2015Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    A sensor device comprising a planar substrate defining a substrate plane and a waveguide for guiding an electromagnetic wave. The waveguide extends in a length direction in a waveguide plane parallel to the substrate plane and has a width and a height, wherein the width to height ratio is more than 5. The height of the waveguide is less than the wavelength of the electromagnetic wave. The waveguide is supported on the substrate by a support structure extending from the substrate to the waveguide, along the length direction of the waveguide, having a width which is smaller than the width of the waveguide. The invention further relates to a method of detecting a component in gas and a method of fabricating a sensor device.

  • 122.
    Hansson, Jonas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    From Lab to Chip – and back: Polymer microfluidic systems for sample handling in point-of-care diagnostics2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis contributes to the development of Lab-on-a-Chip systems that enables reliable, rapid medical diagnostics at the point-of-care. These contributions are focused on microfluidic Lab-on-a-Chip systems for sepsis diagnosis, autonomous sample-to-answer tests, and dried blood spot sampling.

    Sepsis is a serious condition with high mortality and high costs for society and healthcare. To facilitate rapid and effective antibiotic treatment, improved sepsis diagnostics is needed. Diagnosis of sepsis requires the processing of relatively large blood volumes, creating a need for novel and effective techniques for the handling of large volume flows and pressures on chip. Components, materials, and manufacturing methods for pneumatically driven Lab-on-a-Chip systems have therefore been developed in this thesis. Microvalves, an essential component in many Lab-on-a-Chip systems have been the focus on several of the advances: a novel elastomeric material (Rubbery Off-Stoichiometric-Thiol-Ene-Epoxy) with low gas and liquid permeability; the first leak-tight vertical membrane microvalves, allowing large channel cross-sections for high volumetric flow throughput; and novel PDMS manufacturing methods enabling their realization. Additionally, two of the new components developed in this thesis focus on separation of bacteria from blood cells based on differences in particle size, and cell wall composition: inertial microfluidic removal of large particles in multiple parallel microchannels with low aspect ratio; and selective lysis of blood cells while keeping bacteria intact. How these components, materials and methods could be used together to achieve faster sepsis diagnostics is also discussed.

    Lab-on-a-Chip tests can not only be used for sepsis, but have implications in many point-of-care tests. Disposable and completely autonomous sampleto- answer tests, like pregnancy tests, are capillary driven. Applying such tests in more demanding applications has traditionally been limited by poor material properties of the paper-based products used. A new porous material, called “Synthetic Microfluidic Paper”, has been developed in this thesis. The Synthetic Microfluidic Paper features well-defined geometries consisting of slanted interlocked micropillars. The material is transparent, has a large surface area, large porous fraction, and results in low variability in capillary flowrates. The fact that Synthetic Microfluidic Paper can be produced with multiple pore sizes in the same sheet enables novel concepts for self-aligned spotting of liquids and well-controlled positioning of functional microbeads.

    Diagnostic testing can also be achieved by collecting the sample at the point-of-care while performing the analysis elsewhere. Easy collection of finger-prick blood in paper can be performed by a method called dried blood spots. This thesis investigates how the process of drying affects the homogeneity of dried blood spots, which can explain part of the variability that has been measured in the subsequent analysis. To reduce this variability, a microfluidic sampling chip has been developed in this thesis. The chip, which is capillary driven, autonomously collects a specific volume of plasma from a drop of blood, and dry-stores it in paper. After sampling, the chip can be mailed back to a central lab for analysis.

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    Thesis
  • 123.
    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 microvalves in PDMSManuscript (preprint) (Other academic)
  • 124.
    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.

  • 125.
    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.
    Vertical membrane microvalves in PDMS2015In: 2015 28th IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE , 2015, Vol. 2015, no February, p. 563-565Conference paper (Refereed)
    Abstract [en]

    We present the design, realization and evaluation of the first leak-tight vertical membrane pneumatic microvalve. The design freedom in the vertical valve configuration allows for a flow throughput per footprint area that is increased two orders of magnitude compared to horizontal membrane microvalves.

  • 126.
    Hansson, Jonas
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Karlsson, J. Mikael
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Low gas permeable and non-absorbent rubbery OSTE+ for pneumatic microvalves2014In: Proceedings of the 27th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2014), IEEE conference proceedings, 2014, p. 987-990Conference paper (Refereed)
    Abstract [en]

    In this paper we introduce a new polymer for use in microfluidic applications, based on the off-stoichiometric thiol–ene-epoxy (OSTE+) polymer system, but with rubbery properties. We characterize and benchmark the new polymer against PDMS. We demonstrate that Rubbery OSTE+: has more than 90% lower permeability to gases compared to PDMS, has little to no absorption of dissolved molecules, can be layer bonded in room temperature without the need for adhesives or plasma treatment, can be structured by standard micro-molding manufacturing, and shows similar performance as PDMS for pneumatic microvalves, albeit allowing handling of larger pressure. 

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    fulltext
  • 127.
    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%.

    Download full text (pdf)
    Inertial Particle Focusing In Parallel Microfluidic Channels For High-Throughput Filtration
  • 128.
    Hansson, Jonas
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Quelennec, Aurore
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Yasuga, Hiroki
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    Van Der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Synthetic microfluidic paper allows controlled receptor positioning and improved readout signal intensity in lateral flow assays2015In: MicroTAS 2015 - 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences, Chemical and Biological Microsystems Society , 2015, p. 284-286Conference paper (Refereed)
    Abstract [en]

    Synthetic Microfluidic Paper consists of slanted and interlocked polymer micropillars and can be used as a porous substrate in microfluidics and lateral flow assays. We here demonstrate single step manufacturing of multiple Synthetic Microfluidic Paper densities in the same device, and passive alignment of liquid spots in denser substrate regions, regardless of spotting position, allowing increased control of receptor positioning for lateral flow assays. We further demonstrate that the transparency of Synthetic Microfluidic Paper allows increasing readout signal intensity with increasing substrate thickness, to a value 3 times larger compared to nitrocellulose substrates.

  • 129.
    Hansson, Jonas
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Quelennec, Aurore
    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 allows controlled receptor positioning and improvedreadout signal intensity in lateral flow assaysManuscript (preprint) (Other academic)
  • 130.
    Hansson, Jonas
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Yasuga, Hiroki
    Basak, Sarthak
    Mercene Labs, Stockholm, SWEDEN.
    Carlborg, C. Fredrik
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Direct Lithography of Rubbery OSTE+ Polymer2014In: Proceedings 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS2014), 14CBMS , 2014, p. 123-125Conference paper (Refereed)
    Abstract [en]

    We present a Rubbery, Off-Stoichiometric Thiol-Ene-epoxy (OSTE+) polymer for direct lithography manufacturing, demonstrate its use in pneumatic pinch microvalves for lab-on-chip applications, test the lithography process achieving pillars of aspect-ratios (a.r.) 1:8, and characterize it’s surface as hydrophilic.

    Download full text (pdf)
    Hansson_2014_Direct Lithography of Rubbery OSTE+ Polymer.PDF
  • 131.
    Hansson, Jonas
    et al.
    KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Yasuga, Hiroki
    Haraldsson, Klas Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Synthetic paper2017Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    A synthetic paper is manufactured with a method comprising the steps of: a) providing at least two types of pho to-polymerizable monomers, b) exposing the volume to a three-dimensional light pattern to induce a polymerization reaction, and c) removing uncured monomer to create an open microstructure. The volume comprises at least one monomer comprising at least two thiol groups and at least one monomer comprising at least two carbon-carbon double bonds, where the ratio (r1) between the number of thiol groups and the number of carbon-carbon double bonds fulfils one of: 0.5≦r1≦0.9 and 1.1≦r1≦2. One advantage is that off stoichiometry creates an edge effect giving better defined boundaries between exposed and unexposed parts in the volume and giving a possibility to create thinner micro pillars. Another advantage is that it is easy to bind molecules to the surface to obtain desired surface properties.

  • 132.
    Hansson, Jonas
    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 paper2015In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE conference proceedings, 2015, no February, p. 10-13Conference paper (Refereed)
    Abstract [en]

    We introduce a polymer synthetic microfluidic paper for lateral flow devices. The aim is to combine the high surface area of paper, or nitrocellulose, with the repeatability, controlled structure, and transparency of polymer micropillars. Our synthetic paper consists of a dense, high aspect ratio array of transparent pillars that are slanted and mechanically interlocked. We describe the manufacturing using multidirectional UV lithography and demonstrate successful capillary pumping of whole blood.

  • 133.
    Haraldsson, Tommy
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    OSTE - a novel polymer system developed for Lab-on-Chip2014In: Proceedings of SPIE Volume 8976: Microfluidics, BioMEMS, and Medical Microsystems XII, SPIE - International Society for Optical Engineering, 2014, p. 897608-Conference paper (Refereed)
    Abstract [en]

    OSTE polymer has the aim to address today's dissemination gap between successful lab-on-chip research and the healthcare setting. We have formulated and demonstrated a novel, superior, polymer system, OSTE, and its manufacturing platform, which is based on the mixture of three monomers: thiols, -enes and epoxies. The uniqueness of the OSTE approach stems from the curing in two distinct steps: after the first cure, an intermediate polymer is formed which is ideally suited for surface modifications and bonding; after the second cure we obtain an inert and robust polymer. Our vision is that OSTE has the potential to form a de-facto standard for research and development of high performance labs-on-chip in academia and industry.

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    fulltext
  • 134. Hassona, A.
    et al.
    He, Z. S.
    Mariotti, C.
    Dielacher, F.
    Vassilev, V.
    Li, Y.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Zirath, H.
    A non-galvanic D-band MMIC-to-waveguide transition using eWLB packaging technology2017In: 2017 IEEE MTT-S International Microwave Symposium (IMS), Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 510-512, article id 8058612Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel D-band interconnect implemented in a low-cost embedded Wafer Level Ball Grid Array (eWLB) commercial process. The non-galvanic transition is realized through a slot antenna directly radiating to a standard air filled waveguide. The interconnect achieves low insertion loss and relatively wide bandwidth. The measured average insertion loss is 3 dB across a bandwidth of 22% covering the frequency range 110138 GHz. The measured average return loss is -10 dB across the same frequency range. Adopting the low-cost eWLB process and standard waveguides makes the transition an attractive solution for interconnects beyond 100 GHz. This solution enables mm-wave system on chip (SoC) to be manufactured and assembled in high volumes cost effectively. To the authors' knowledge, this is first attempt to fabricate a packaging solution beyond 100 GHz using eWLB technology.

  • 135.
    Hillmering, Mikael
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Polymer microfluidic systems for samplepreparation for bacterial detection2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sepsis, caused by blood stream infection, is a very serious health condition thatrequires immediate treatment using antibiotics to increase the chances for patientsurvival. A high prevalence of antibiotic resistance among infected patients requiresstrong and toxic antibiotics to ensure effective treatment. A rapid diagnostic devicefor detection of antibiotic resistance genes in pathogens in patient blood would enablean early change to accurate and less toxic antibiotics. Although there is a pressingneed for such devices, rapid diagnostic tests for sepsis do not yet exist.In this thesis, novel advances in microfabrication and lab-on-a-chip devices arepresented. The overall goal is to develop microfluidics and lab-on-a-chip systems forrapid sepsis diagnostics. To approach this goal, novel manufacturing techniques formicrofluidics systems and novel lab-on-a-chip devices for sample preparation havebeen developed.Two key problems for analysis of blood stream infection samples are that lowconcentrations of bacteria are typically present in the blood, and that separation ofbacteria from blood cells is difficult. To ensure that a sufficient amount of bacteria isextracted, large sample volumes need to be processed, and bacteria need to be isolatedwith high efficiency. In this thesis, a particle filter based on inertial microfluidicsenabling high processing flow rates and integration with up- and downstream processesis presented.Another important function for diagnostic lab-on-a-chip devices is DNA amplificationusing polymerase chain reaction (PCR). A common source of failure for PCRon-chip is the formation of bubbles during the analysis. In this thesis, a PCR-on-chipsystem with active degassing enabling fast bubble removal through a semipermeablemembrane is presented.Several novel microfabrication methods were developed. Novel fabrication techniquesusing the polymer PDMS that enable manufacturing of complex lab-on-a-chipdevices containing 3D fluidic networks and fragile structures are presented. Also,a mechanism leading to increased accuracy in photopatterning in thiol-enes, whichenables rapid prototyping of microfluidic devices, is described. Finally, a novel flexibleand gas-tight polymer formulation for microfabrication is presented: rubbery OSTE+.Together, the described achievements lead to improved manufacturing methodsand performances of lab-on-a-chip devices, and may facilitate future development ofdiagnostic devices.

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    Thesis
  • 136. Hultström, M.
    et al.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Nordquist, L.
    Intradermal insulin delivery: A promising future for diabetes management2014In: Journal of Diabetes Science and Technology, E-ISSN 1932-2968, Vol. 8, no 3, p. 453-457Article in journal (Refereed)
    Abstract [en]

    The incidence of insulinopenic diabetes mellitus is constantly increasing, and in addition, approximately a third of all hyperinsulinemic diabetic patients develop insulinopenia. Optimal glycemic control is essential to minimize the risk for diabetes-induced complications, but the majority of diabetic patients fail to achieve proper long-term glucose levels even in clinical trials, and even more so in clinical practice. Compliance with a treatment regimen is likely to be higher if the procedure is simple, painless, and discreet. Thus, insulin has been suggested for nasal, gastrointestinal, and inhalation therapy, but so far with considerable downsides in effect, side effects, or patient acceptance. The stratum corneum is the main barrier preventing convenient drug administration without the drawbacks of subcutaneous injections. Recently, devices with miniaturized needles have been developed that combine the simplicity and discretion of patch-based treatments, but with the potential of peptide and protein administration. As this review describes, initial comparisons with subcutaneous administration now suggest microneedle patches for active insulin delivery are efficient in maintaining glycemic control. Hollow microneedle technology could also prove to be efficient in systemic as well as local delivery of other macromolecular drugs, such as vaccines.

  • 137.
    Imani Jajarmi, Ramin
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Ladhani, Laila
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Pardon, Gaspard
    Metsola van Der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Robert, Etienne
    The Influence of Air Flow Velocity and Particle Size on the Collection Efficiency of Electrostatic Aerosol SamplersManuscript (preprint) (Other academic)
  • 138.
    Iovan, Adrian
    et al.
    KTH.
    Fischer, Marco
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Lo Conte, Roberto
    KTH.
    Korenivski, Vladislav
    KTH, School of Engineering Sciences (SCI), Applied Physics, Nanostructure Physics.
    Sub-10 nm colloidal lithography for circuit-integrated spin-photo-electronic devices2012In: Beilstein Journal of Nanotechnology, ISSN 2190-4286, Vol. 3, p. 884-892Article in journal (Refereed)
    Abstract [en]

    Patterning of materials at sub-10 nm dimensions is at the forefront of nanotechnology and employs techniques of various complexity, efficiency, areal scale, and cost. Colloid-based patterning is known to be capable of producing individual sub-10 nm objects. However, ordered, large-area nano-arrays, fully integrated into photonic or electronic devices have remained a challenging task. In this work, we extend the practice of colloidal lithography to producing large-area sub-10 nm point-contact arrays and demonstrate their circuit integration into spin-photo-electronic devices. The reported nanofabrication method should have broad application areas in nanotechnology as it allows ballistic-injection devices, even for metallic materials with relatively short characteristic relaxation lengths.

  • 139.
    Johansson, Staffan B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Eklund, Anders
    Malm, Jan
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A MEMS-based passive hydrocephalus shunt for body position controlled intracranial pressure regulation2014In: Biomedical microdevices (Print), ISSN 1387-2176, E-ISSN 1572-8781, Vol. 16, no 4, p. 529-536Article in journal (Refereed)
    Abstract [en]

    This paper reports a novel micro electro mechanical system (MEMS) valve with posture controlled flow characteristics for improved treatment of hydrocephalus, a disease that is characterized by elevated pressure in the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. In contrast to conventional differential pressure CSF valves, the CSF valve presented here features a third port which utilizes hydrostatic pressure from a pressure compensating catheter to adapt CSF drainage to optimized levels irrespective of body position. Prototypes have been fabricated using standard MEMS manufacturing processes and the experimental evaluation successfully showed that the flow rate was adjustable with a varying hydrostatic pressure on the third port. Measured data showed that flow rate was at near ideal values at laying body position and that the flow rate can be adjusted to optimal values at standing body position by selecting an appropriate length of the pressure compensating catheter. This is the first pressure balanced CSF valve intended for body position controlled CSF pressure regulation.

  • 140.
    Johansson, Staffan B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A compact passive air flow regulator for portable breath diagnostics2013In: Micro Electro Mechanical Systems (MEMS), 2013 IEEE 26th International Conference on, New York: IEEE , 2013, p. 157-160Conference paper (Refereed)
    Abstract [en]

    This work reports on a compact flow regulator designed to maintain a steady flow during breath diagnostics. The fabricated device consists of six in-plane moving pistons that restrict the flow through six flow orifices, controlling comparatively large air flows up to 50 ml/s at a pressure range of 1-2 kPa on a chip of only 2x2x4 mm3. The device is fabricated from three wafers, including an SOI wafer, using standard silicon micromachining and only three masks. The in-plane design also allows for scaling of the flow and pressure range by changing the thickness of the handle wafer and device layer. Experimental evaluation of the prototype shows that flow rate is regulated close to the dictated requirements for FENO asthma monitoring.

  • 141.
    Johansson, Staffan B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A novel constant flow regulation principle for compact breath diagnostics2014In: 2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS), IEEE , 2014, p. 935-938Conference paper (Refereed)
    Abstract [en]

    This work reports on a passive compact flow regulator designed to maintain a steady flow during breath diagnostics using a flow regulation principle where a cantilever is directed towards the direction of the flow. A theoretical model has been developed describing the flow behavior and a prototype has been fabricated for proof of concept. The prototype uses a single integrated 300 μm thick 3D-printed plastic cantilever to control comparatively large air flows in the 50 ml/s regime suitable for asthma diagnostics.

  • 142.
    Johansson, Staffan
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Eklund, Anders
    Umeå University.
    Malm, Jan
    Umeå University.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A MEMS-based passive hydrocephalus shunt with adaptive flow characteristics2013Conference paper (Refereed)
    Abstract [en]

    This paper reports a novel MEMS valve with adaptive flow characteristics for improved treatment of hydrocephalus, a disease that is characterized by elevated pressure in the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. In contrast to conventional valves with two ports, the valve presented here features a third port, called compensation port, which utilizes hydrostatic pressure to adapt CSF drainage based on body position. A prototype has been fabricated using standard MEMS manufacturing processes and the experimental evaluation successfully showed that the flow rate was adjustable with a varying hydrostatic pressure on the compensation port. Extracted data shows that flow rate was at near ideal values at both standing and laying body position showing an effective adaptation to body position. This is the first passive hydrocephalus valve intended for body position dependent CSF pressure regulation.

  • 143.
    Johansson, Staffan
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    A MEMS-based passive air flow regulator for handheld breath diagnostics2014In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 215, p. 65-70Article in journal (Refereed)
    Abstract [en]

    This paper reports on a passive MEMS-based flow regulator designed to maintain a steady flow during asthma diagnostics. A prototype consisting of six in-plane moving pistons that restrict the flow through six flow orifices has been fabricated from three wafers using standard silicon micromachining. The in-plane design enables relatively large flows and tuning of the flow and pressure range to specific application requirements by changing a wafer thickness. In particular, for FENO asthma monitoring, regulatory guidelines specifies that measurements should be made at steady flow of approximately 50 ml/s and within a pressure range of 1–2 kPa. Experimental evaluation of the prototype shows that the flow rate is controlled within a dynamic pressure range of 770 Pa compared to only 430 Pa for a dummy structure and that it can be achieved on a chip measuring only 2 mm × 2 mm × 4 mm. The evaluation also showed that condensation of exhaled air that expectedly occurs in the flow regulator at room temperature can be eliminated by local heating of the device to 40◦C.

  • 144.
    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.

    Download full text (pdf)
    Hansson_2016_Synthetic-microfluidic-paper.pdf
  • 145.
    Karlsson, J. Mikael
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Gazin, Muriel
    Universiteit Antwerpen.
    Laakso, Sanna
    Mobidiag Ltd.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Malhotra-Kumar, Surbhi
    Universiteit Antwerpen.
    Mäki, Minna
    Orion Diagnostica Oy.
    Goossens, Herman
    Universiteit Antwerpen.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Active liquid degassing in microfluidic systems2013In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 13, no 22, p. 4366-4373Article in journal (Refereed)
    Abstract [en]

    We present a method for efficient air bubble removal in microfluidic applications. Air bubbles are extracted from a liquid chamber into a vacuum chamber through a semipermeable membrane, consisting of PDMS coated with amorphous Teflon (R) AF 1600. Whereas air is efficiently extracted through the membrane, water loss is greatly reduced by the Teflon even at elevated temperatures. We present the water loss and permeability change with the amount of added Teflon AF to the membrane. Also, we demonstrate bubble-free, multiplex DNA amplification using PCR in a PDMS microfluidic device.

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  • 146.
    Karlsson, J. Mikael
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hansson, Jonas
    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 microvalves in PDMS enabled by a novel 3D manufacturing processManuscript (preprint) (Other academic)
  • 147.
    Karlsson, J. Mikael
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Pardon, Gaspard
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Vastesson, Alexander
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Supekar, Omkar
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Brandner, Brigit
    SP Technical Research Institute of Sweden.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Off-Stoichiometry Improves Photostructuring of Thiol-Enes Through Diffusion-Induced Monomer Depletion2016In: Microsystems and Nanoengineering, ISSN 2055-7434, Vol. 2, article id 15043Article in journal (Refereed)
    Abstract [en]

    Thiol-enes are a group of alternating copolymers with highly ordered networks used in a wide range of applications. Here, “click” chemistry photostructuring in off-stoichiometric thiol-enes is shown to induce microscale polymeric compositional gradients due to species diffusion between non-illuminated and illuminated regions, creating two narrow zones with distinct composition on either side of the photomask feature boundary: a densely cross-linked zone in the illuminated region and a zone with an unpolymerized highly off-stoichiometric monomer composition in the non-illuminated region. By the use of confocal Raman microscopy, it is here explained how species diffusion causes such intricate compositional gradients in the polymer, and how off-stoichiometry results in improved image transfer accuracy in thiol-ene photostructuring. Furthermore, increasing the functional group off-stoichiometry and decreasing photomask feature size is shown to amplify the induced gradients, which potentially leads to a new methodology for microstructuring.

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  • 148. Khan, U.
    et al.
    Bogaerts, W.
    Quack, N.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Verheyen, P.
    O'Brien, P.
    Arce, C.L.
    Garcia, M.
    The MORPHIC Project: Enabling large scale programmable photonic circuits using MEMS2018Conference paper (Other academic)
    Abstract [en]

    In MORPHIC, we are enhancing the capabilities of already established silicon photonics platform with low-power and non-volatile MEMS actuators to achieve programmability and re-configurability of the photonic circuits. The combining of high speed silicon photonics, non-volatile MEMS actuation, electronics controlled reconfigurable connectivity and high level design methodologies and programming interface in a package will lead to a complete Field-Programmable Photonic Integrated Circuits (FP-PIC) platform. Ultimately, technology platforms for both generic FP-PIC and Application-Specific Photonic Integrated Circuits (AS-PIC) with possibility of volume manufacturing will be demonstrated.

  • 149. Khorramdel, Behnam
    et al.
    Liljeholm, Jessica
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems. Silex Microsystems AB.
    Laurila, Mika-Matti
    Lammi, Toni
    Mårtensson, Gustaf
    Ebefors, Thorbjörn
    Niklaus, Frank
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Mäntysalo, Matti
    Inkjet printing technology for increasing the I/O density of 3D TSV interposers2017In: Microsystems & Nanoengineering, E-ISSN 2055-7434, Vol. 3, p. 17002-Article in journal (Refereed)
    Abstract [en]

    Interposers with through-silicon vias (TSVs) play a key role in the three-dimensional integration and packaging of integrated circuits and microelectromechanical systems. In the current practice of fabricating interposers, solder balls are placed next to the vias; however, this approach requires a large foot print for the input/output (I/O) connections. Therefore, in this study, we investigate the possibility of placing the solder balls directly on top of the vias, thereby enabling a smaller pitch between the solder balls and an increased density of the I/O connections. To reach this goal, inkjet printing (that is, piezo and super inkjet) was used to successfully fill and planarize hollow metal TSVs with a dielectric polymer. The under bump metallization (UBM) pads were also successfully printed with inkjet technology on top of the polymer-filled vias, using either Ag or Au inks. The reliability of the TSV interposers was investigated by a temperature cycling stress test (-40 °C to +125 °C). The stress test showed no impact on DC resistance of the TSVs; however, shrinkage and delamination of the polymer was observed, along with some micro-cracks in the UBM pads. For proof of concept, SnAgCu-based solder balls were jetted on the UBM pads.

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  • 150. Knechtel, Roy
    et al.
    Niklaus, Frank
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Michel, Bernd
    Special issue WaferBond'13 "International Conference on Wafer Bonding for MEMS Technologies and Wafer Level Integration"2015In: Microsystem Technologies: Micro- and Nanosystems Information Storage and Processing Systems, ISSN 0946-7076, E-ISSN 1432-1858, Vol. 21, no 5, p. 951-951Article in journal (Other academic)
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