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• 1.
MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA..
MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.;MIT, Inst Med Engn & Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.. MIT, Inst Med Engn & Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.;Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.;MIT, Div Comparat Med, Cambridge, MA 02139 USA.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Novo Nordisk AS, Global Res Technol, Global Drug Discovery & Device R&D, Copenhagen, Denmark.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.;MIT, Inst Med Engn & Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Media Lab, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA.;MIT, Dept Mech Engn, Cambridge, MA 02139 USA.;Harvard Med Sch, Brigham & Womens Hosp, Div Gastroenterol, Boston, MA 02115 USA..
An ingestible self-orienting system for oral delivery of macromolecules2019In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 363, no 6427, p. 611-+Article in journal (Refereed)

Biomacromolecules have transformed our capacity to effectively treat diseases; however, their rapid degradation and poor absorption in the gastrointestinal (GI) tract generally limit their administration to parenteral routes. An oral biologic delivery system must aid in both localization and permeation to achieve systemic drug uptake. Inspired by the leopard tortoise's ability to passively reorient, we developed an ingestible self-orienting millimeter-scale applicator (SOMA) that autonomously positions itself to engage with GI tissue. It then deploys milliposts fabricated from active pharmaceutical ingredients directly through the gastric mucosa while avoiding perforation. We conducted in vivo studies in rats and swine that support the applicator's safety and, using insulin as a model drug, demonstrated that the SOMA delivers active pharmaceutical ingredient plasma levels comparable to those achieved with subcutaneous millipost administration.

• 2.
MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA..
MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Inst Med Engn & Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Inst Med Engn & Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Div Comparat Med, Cambridge, MA 02139 USA.. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA.;MIT, Elect Res Lab, Cambridge, MA 02139 USA.. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA.;MIT, Elect Res Lab, Cambridge, MA 02139 USA.. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA.;MIT, Elect Res Lab, Cambridge, MA 02139 USA.. Global Drug Discovery, Global Res Technol, Malov, Denmark.;Novo Nordisk, Device R&D, Malov, Denmark.. Global Drug Discovery, Global Res Technol, Malov, Denmark.;Novo Nordisk, Device R&D, Malov, Denmark.. Global Drug Discovery, Global Res Technol, Malov, Denmark.;Novo Nordisk, Device R&D, Malov, Denmark.. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Inst Med Engn & Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Dept Mech Engn, Cambridge, MA 02139 USA.;MIT, Media Lab, Cambridge, MA 02139 USA.. MIT, Dept Chem Engn, Cambridge, MA 02139 USA.;MIT, David H Koch Inst Integrat Canc Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Dept Mech Engn, Cambridge, MA 02139 USA.;Harvard Med Sch, Brigham & Womens Hosp, Div Gastroenterol, Boston, MA 02115 USA..
A luminal unfolding microneedle injector for oral delivery of macromolecules2019In: Nature Medicine, ISSN 1078-8956, E-ISSN 1546-170X, Vol. 25, no 10, p. 1512-+Article in journal (Refereed)

Insulin and other injectable biologic drugs have transformed the treatment of patients suffering from diabetes(1,2), yet patients and healthcare providers often prefer to use and prescribe less effective orally dosed medications(3-5). Compared with subcutaneously administered drugs, oral formulations create less patient discomfort(4), show greater chemical stability at high temperatures(6), and do not generate biohazardous needle waste(7). An oral dosage form for biologic medications is ideal; however, macromolecule drugs are not readily absorbed into the bloodstream through the gastrointestinal tract(8). We developed an ingestible capsule, termed the luminal unfolding microneedle injector, which allows for the oral delivery of biologic drugs by rapidly propelling dissolvable drug-loaded microneedles into intestinal tissue using a set of unfolding arms. During ex vivo human and in vivo swine studies, the device consistently delivered the microneedles to the tissue without causing complete thickness perforations. Using insulin as a model drug, we showed that, when actuated, the luminal unfolding microneedle injector provided a faster pharmacokinetic uptake profile and a systemic uptake > 10% of that of a subcutaneous injection over a 4-h sampling period. With the ability to load a multitude of microneedle formulations, the device can serve as a platform to orally deliver therapeutic doses of macromolecule drugs.

• 3.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Freeze-Dried Carbon Nanotube Aerogels for High-Frequency Absorber Applications2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, ISSN 1944-8244, Vol. 10, no 23, p. 19806-19811Article in journal (Refereed)

A novel technique for millimeter wave absorber material embedded in a metal waveguide is proposed. The absorber material is a highly porous carbon nanotube (CNT) aerogel prepared by a freeze-drying technique. CNT aerogel structures are shown to be good absorbers with a low reflection coefficient, less than -12 dB at 95 GHz. The reflection coefficient of the novel absorber is 3-4 times lower than that of commercial absorbers with identical geometry. Samples prepared by freeze-drying at -25 degrees C demonstrate resonance behavior, while those prepared at liquid nitrogen temperature (-196 degrees C) exhibit a significant decrease in reflection coefficient, with no resonant behavior. CNT absorbers of identical volume based on wet-phase drying preparation show significantly worse performance than the CNT aerogel absorbers prepared by freeze-drying. Treatment of the freeze-dried CNT aerogel with n- and p-dopants (monoethanolamine and iodine vapors, respectively) shows remarkable improvement in the performance of the waveguide embedded absorbers, reducing the reflection coefficient by 2 dB across the band.

• 4.
Karolinska Inst, Dept Lab Med, Stockholm, Sweden..
Karolinska Inst, Dept Lab Med, Stockholm, Sweden.. Karolinska Inst, Dept Lab Med, Stockholm, Sweden.. Karolinska Univ Hosp, Stockholm, Sweden.. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Pharmacokinetics of methylphenidate in plasma, exhaled breath, oral fluid and dried blood spots after a single oral dose of ritalin 20 mg2019In: European Journal of Clinical Pharmacology, ISSN 0031-6970, E-ISSN 1432-1041, Vol. 75, p. S89-S90Article in journal (Other academic)
• 5.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH.
A Study of Surface Treatments and Voids Formation in Low Temperature Wafer BondingManuscript (preprint) (Other academic)
• 6.
KTH, School of Engineering Sciences (SCI), Applied Physics.
KTH, School of Engineering Sciences (SCI), Applied Physics. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Engineering Sciences (SCI), Applied Physics.
Waveguide Gratings in Thin-Film Lithium Niobate on Insulator2017In: 2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC), IEEE , 2017Conference paper (Refereed)
• 7.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Real-Time Monitoring of Neurovascular Cells2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Organs-on-a-chip devices are perfused cell culture systems aimed at creating the minimal functional unit of an organ - suchas the neurovascular unit (NVU) of the brain. NVU-on-a-chip platforms can provide an effective framework for studyingcentral nervous system physiology, disease etiology and provide a mean for drug development.In this work, we investigated the possibility of developing NVU-on-a-chip devices, with real-time sensing capabilitiesof glucose - intended for monitoring the metabolic activity of neurovascular cells. This was done by evaluating theperformance and applicability of in-house ultra-miniaturized glucose sensor technology and commercial DropSence (DS)electrodes, as well as studying astrocytoma characteristics.Firstly the performance of the amperometric microsensors was assessed - demonstrating a sufficient linear detectionrange (6, 2±0, 7 mM) for monitoring normal glucose levels of the brain (0, 5−1, 5 mM) and a high sensitivity (0, 09±0, 02mA/mM/mm2) . Limit of detection (LOD) ranged between 0, 04 mM for the 3_2 model microsensor to up to to 0, 14±0, 05mM for the DS electrodes. Limit of detectable change (LO4S), obtained from deviations between repeated measurements,was found to be approximately 0, 6 mM for all the sensors - close to the normal glucose concentrations of the brain. Limitof detectable change (LO4N), obtained from signal-noise within single measurements, was smallest for the biggest DSelectrodes (0, 04 mM).Secondly the compatibility of sensor materials (substrate and functional membranes) with astrocytoma cells was tested.Cell viability and growth, in conjunction with test materials, were assessed and compared to that of glass and/or cellculturetreated polystyrene (plastic). The materials tested were: Nafion; polyurethane (PU); Glucose Oxidase/bovineserum albumin/glutaraldehyde (GOx/GA); and silicon substrate with SiO2 surface. Cell viability and growth provedalmost as good on nafion membrane as on plastic and glass, while the enzyme containing layer proved to be toxic - mostlikely due to the protein-reactive crosslinker glutaraldehyde. PU-membrane showed significantly lower performance thanglass but demonstrated the best ability to encapsulate the toxic effect of the innermost enzyme layer. In contrast, nafioncoverage resulted in a lack of cells adjacent to the membrane - suggesting partial permeability to the harmful compoundsof the innermost layer. The SiO2surface of the silicon substrate, demonstrated significantly lower performance than plasticin terms of cell viability and growth.Thirdly glucose uptake rates of astrocytoma cell were determined. Depending on glucose availability in the the test wellsthe cells demonstrated a wide range of uptake rates: between 6, 5 · 10

• 8. Beck, O.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Study of measurement of the alcohol biomarker phosphatidylethanol (PEth) in dried blood spot (DBS) samples and application of a volumetric DBS device2018In: Clinica Chimica Acta, ISSN 0009-8981, E-ISSN 1873-3492, Vol. 479, p. 38-42Article in journal (Refereed)

Phosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption. PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and medico-legal applications. This study further evaluated the usefulness of dried blood spot (DBS) samples collected on filter paper for PEth measurement. Specimens used were surplus volumes of venous whole blood sent for routine LC–MS/MS quantification of PEth 16:0/18:1, the major PEth homolog. DBS samples were prepared by pipetting blood on Whatman 903 Protein Saver Cards and onto a volumetric DBS device (Capitainer). The imprecision (CV) of the DBS sample amount based on area and weight measurements of spot punches were 23–28%. Investigation of the relationship between blood hematocrit and PEth concentration yielded a linear, positive correlation, and at around 1.0–1.5 μmol/L PEth 16:0/18:1, the PEth concentration increased by ~ 0.1 μmol/L for every 5% increase in hematocrit. There was a close agreement between the PEth concentrations obtained with whole blood samples and the corresponding results using Whatman 903 (PEthDBS = 1.026 PEthWB + 0.013) and volumetric device (PEthDBS = 1.045 PEthWB + 0.016) DBS samples. The CV of PEth quantification in DBS samples at concentrations ≥ 0.05 μmol/L were ≤ 15%. The present results further confirmed the usefulness of DBS samples for PEth measurement.

• 9.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Low-Loss Silicon Micromachined Waveguides Above 100 GHz Utilising Multiple H-plane Splits2018In: Proceedings of the 48th European Microwave Conference, Madrid, October 1-3, 2018, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1041-1044, article id 8541605Conference paper (Refereed)

For sub-millimeter and millimeter wave applications rectangular waveguides are an ideal transmission medium. Compared to conventional, metal-milled rectangular waveguides, silicon micromachined waveguides offer a number of advantages. In this paper we present a low-loss silicon micromachined waveguide technology based on a double H-plane split for the frequency bands of 110 – 170 GHz and 220 – 330 GHz. For the upper band a reduced height waveguide is presented, which achieves a loss per unit length of 0.02 – 0.10 dB/mm. This technology has been further adapted to implement a full height waveguide for the lower frequency band of 110 – 170 GHz. The full height waveguide takes advantage of the benefits of the double H-plane split technique to overcome the challenges of fabricating micromachined waveguides at lower frequencies. With measured insertion loss of 0.007 – 0.013 dB/mm, averaging 0.009 dB/mm over the whole band, this technology offers the lowest insertion loss of any D-band waveguide to date. The unloaded Q factor of the D-band waveguide technology is estimated to be in excess of 1600, while a value of 750 has been measured for the reduced height upper band waveguide.

• 10.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
Micromachined Waveguides with Integrated Silicon Absorbers and Attenuators at 220–325 GHz2018In: IEEE MTT-S International Microwave Symposium, IEEE conference proceedings, 2018 / [ed] IEEE, IEEE, 2018Conference paper (Refereed)

This paper reports for the first time on micromachined waveguides with integrated micromachined silicon absorbers. In contrast to epoxy-based microwave absorbers, micromachined lossy silicon absorbers are fully compatible with high temperature fabrication and assembly processes for micromachined waveguides. Furthermore, micromachining enables the fabrication of exact, near ideal taper tips for the silicon absorbers, whereas the tip of epoxy-based absorbers cannot be shaped accurately and reproducibly for small waveguides. Silicon of different conductivity is a very well understood and characterized dielectric material, in contrast to conventional absorber materials which are not specified above 60 GHz. Micromachined silicon waveguides with integrated absorbers and attenuators were designed, fabricated and characterized in the frequency band of 220 – 325 GHz. The return and insertion loss for various taper-geometry variations of double-tip tapered absorbers and attenuators was studied. The average return loss for the best investigated device is 19 dB over the whole band. The insertion loss of the two-port attenuators is 16 – 33 dB for different designs and shows an excellent agreement to the simulated results. The best measured devices of the one-port absorbers exhibit an average and worst-case return loss of 22 dB and 14 dB, respectively, over the whole band. The return loss is not characterized by a good simulation-measurement match, which is most likely attributed to placement tolerances of the absorbers in the waveguide cavities affecting the return but not the insertion loss.

• 11.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Adhesive Wafer Bonding for Heterogeneous System Integration2018In: ECS Meeting Abstracts / [ed] The Electrochemical Society, 2018Conference paper (Refereed)
• 12.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering (EES), Micro and Nanosystems. KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
Low-Loss Hollow and Silicon-Core Micromachined Waveguide Technologies Above 100 GHz2018Conference paper (Other academic)
• 13.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Ericsson Research. Ericsson Research. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
An Ultra Low-Loss Silicon-Micromachined Waveguide Filter for D-Band Telecommunication Applications2018In: 2018 IEEE/MTT-S International Microwave Symposium, IEEE, 2018, p. 583-586Conference paper (Refereed)

A very low-loss micromachined waveguide bandpassfilter for use in D-band (110–170GHz) telecommunication applicationsis presented. The 134–146GHz filter is implemented in a silicon micromachined technology which utilises a double H-plane split, resulting in significantly lower insertion loss than conventional micromachined waveguide devices. Custom split-blocks are designed and implemented to interface with the micromachined component. Compact micromachined E-plane bends connect the split-blocks and DUT. The measured insertion loss per unit length of the waveguide technology (0.008–0.016 dB/mm) is the lowest reported to date for any micromachined waveguide at D-band. The fabricated 6-pole filter, with a bandwidth of 11.8 GHz (8.4%), has a minimum insertion loss of 0.41 dB, averaging 0.5 dB across its 1 dB bandwidth, making it the lowest-loss D-band filter reported to date in any technology. Its return loss is better than 20 dB across 85% of the same bandwidth. The unloaded quality factor of a single cavity resonator implemented in this technology is estimated to be 1600.

• 14.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
Toward Industrial Exploitation of THz Frequencies: Integration of SiGe MMICs in Silicon-Micromachined Waveguide Systems2019In: IEEE transactions on rehabilitation engineering, ISSN 1063-6528, E-ISSN 1558-0024, Vol. 9, no 6, p. 624-636Article in journal (Refereed)

A new integration concept for terahertz (THz) systems is presented in this article, wherein patterned silicon-on-insulator wafers form all DC, IF, and RF networks in a homogeneous medium, in contrast to existing solutions. Using this concept, silicon-micromachined waveguides are combined with silicon germanium (SiGe) monolithic microwave integrated circuits (MMICs) for the first time. All features of the integration platform lie in the waveguide’s H-plane. Heterogeneous integration of SiGe chips is achieved using a novel in-line H-plane transition. As an initial step toward complete systems, we outline the design, fabrication, and assembly of back-to-back transition structures, for use at D-band frequencies (110ï¿œ170 GHz). Special focus is given to the industrial compatibility of all components, fabrication, and assembly processes, with an eye on the future commercialization of THz systems. Prototype devices are assembled via two distinct processes, one of which utilizes semiautomated die-bonding tools. Positional and orientation tolerances for each process are quantified. An accuracy of $\pm \text3.5\; μ \textm$, $\pm \text1.5 °$ is achieved. Measured $S$-parameters for each device are presented. The insertion loss of a single-ended transition, largely due to MMIC substrate losses, is 4.2ï¿œ5.5 dB, with a bandwidth of 25 GHz (135ï¿œ160 GHz). Return loss is in excess of 5 dB. Measurements confirm the excellent repeatability of the fabrication and assembly processes and, thus, their suitability for use in high-volume applications. The proposed integration concept is highly scalable, permitting its usage far into the THz frequency spectrum. This article represents the first stage in the shift to highly compact, low-cost, volume-manufacturable THz waveguide systems.

• 15.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Silicon-Micromachined Waveguide Calibration Shims for Terahertz Frequencies2019Conference paper (Refereed)

A new method of realising precision waveguide shims for use in THz Through-Reflect-Line (TRL) calibrations, based on silicon-micromachining, is introduced. The proposed calibration shims combine a thin λ/4 silicon layer, co-fabricated with a thicker layer which provides mechanical support. This design overcomes the limitations of CNC milling for the creation of calibration shims, facilitating use of standard TRL calibration at currently challenging frequencies. The novel shim fits inside the inner recess of a standard waveguide flange and is compatible with conventional flange alignment pins. Five micromachined shims were fabricated in a silicon-on-insulator process for operation in the WM-570 waveguide band (325–500GHz). The fabricated shims show excellent performance across the entire band, with return loss in excess of 25dB, insertion loss below 0.2 dB and high uniformity between samples. Verification reveals that the micromachined shims have an electrical length within 2% of the expected value. Comparative measurements of a DUT calibrated with the proposed shim and a previously un-used conventional metallic shim show that the novel concept offers equivalent, if not better, performance. The mechanical design of the micromachined shim and the rigid nature of silicon ensure that it will not suffer from performance degradation with repeated use, as is problematic with thin metallic shims. This work enables the creation of low-cost, highly-repeatable, traceable calibration shims with micrometer feature-sizes and high product uniformity, surpassing the limits of current techniques.

• 16.
Centre for Biological Engineering, Loughborough University, UK.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Centre for Biological Engineering, Loughborough University, UK. Department of Chemistry, University of Cambridge, UK. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Department of Chemistry, University of Cambridge, UK. Centre for Biological Engineering, Loughborough University, UK.
Characterisation of particle-surface interactions via anharmonic acoustic transduction2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 272, p. 175-184Article in journal (Refereed)
• 17.
Uppsala University.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Uppsala University. FOI. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Uppsala University.
Leaky Wave Antenna at 300 GHz in KTH’s Micromachined Waveguide Technology2018Conference paper (Other academic)
• 18.
Uppsala University.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH, School of Electrical Engineering (EES), Micro and Nanosystems. KTH, School of Electrical Engineering (EES), Micro and Nanosystems. Uppsala University.
Leaky Wave Antenna at 300 GHz in Silicon Micromachined Waveguide Technology2019In: 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), IEEE, 2019Conference paper (Refereed)

A leaky wave antenna composed of eight slots in a gold metallised silicon micromachined waveguide was designed, fabricated and measured at 300 GHz. The measured results are in good agreement with the simulations.

• 19. Delsing, Louise
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Barrier properties and transcriptome expression in human iPSC‐derived models of the blood–brain barrier2018In: Stem Cells, ISSN 1066-5099, E-ISSN 1549-4918, Vol. 36, no 12, p. 1816-1827Article in journal (Refereed)

Cell-based models of the blood-brain barrier (BBB) are important for increasing the knowledge of BBB formation, degradation and brain exposure of drug substances. Human models are preferred over animal models because of interspecies differences in BBB structure and function. However, access to human primary BBB tissue is limited and has shown degeneration of BBB functions in vitro. Human induced pluripotent stem cells (iPSCs) can be used to generate relevant cell types to model the BBB with human tissue. We generated a human iPSC-derived model of the BBB that includes endothelial cells in coculture with pericytes, astrocytes and neurons. Evaluation of barrier properties showed that the endothelial cells in our coculture model have high transendothelial electrical resistance, functional efflux and ability to discriminate between CNS permeable and non-permeable substances. Whole genome expression profiling revealed transcriptional changes that occur in coculture, including upregulation of tight junction proteins, such as claudins and neurotransmitter transporters. Pathway analysis implicated changes in the WNT, TNF, and PI3K-Akt pathways upon coculture. Our data suggest that coculture of iPSC-derived endothelial cells promotes barrier formation on a functional and transcriptional level. The information about gene expression changes in coculture can be used to further improve iPSC-derived BBB models through selective pathway manipulation.

• 20.
ITMO Univ, St Petersburg 197101, Russia..
ITMO Univ, St Petersburg 197101, Russia.. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. ITMO Univ, St Petersburg 197101, Russia.. ITMO Univ, St Petersburg 197101, Russia..
Influence of optical pumping on properties of carbon nanotubes with different geometric parameters in THz frequency range2018In: 2018 43RD INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ), IEEE , 2018Conference paper (Refereed)

Impact of infrared radiation illumination (980 nm) on the properties of cabon nanotubes (CNT), such as complex conductivity and permittivity, with different geometric parameters (lengths, diameters and with presence/absence graphene oxide layer) in the frequency range of 0.2-1.0 THz was studied.

• 21. Demchenko, P.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Study of optical pumping influence on carbon nanotubes permittivity in THz frequency range2018In: Journal of Physics: Conference Series, Institute of Physics Publishing , 2018, no 5Conference paper (Refereed)

Equivalent complex permittivity of carbon nanotubes (CNT) was measured with/without light illumination at the frequency range of 0.2-1 THz. It was shown that we can tune the dispersion of the CNT complex conductivity during varying of optical pumping (wavelength of 980 nm). These results mean that CNT is perspective candidate for development of THz tunable attenuators and phase shifters.

• 22. Demchenko, P.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Study of influence of densification on control of conductivity and spectral characteristics of thin films of carbon nanotubes in terahertz frequency range2018In: EPJ Web of Conferences, EDP Sciences, 2018, article id 06022Conference paper (Refereed)
• 23. Divagar, M
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. VIT Vellore, Sch Biosci & Technol, Vellore 632014, Tamil Nadu, India.
Self-assembled polyamidoamine dendrimer on poly (methyl methacrylate) for plasmonic fiber optic sensors2019In: ChemNanoMat, ISSN 2199-692XArticle in journal (Refereed)

We report a novel one-step polyamidoamine (PAMAM) dendrimer based polymethyl methacrylate (PMMA) surface functionalization strategy for the development of polymeric optical fiber (POF) based plasmonic sensors utilizing gold nanoparticles (AuNP). Simple contact angle measurements over PMMA sheets reveal the ability of the dendrimers to strongly bind to PMMA surface without additional acid/alkali pretreatment, unlike the conventional hexamethylene diamine (HMDA) based surface modification. Subsequently, U-bent POF probes with high evanescent wave absorbance sensitivity were exploited for relative quantification of the surface amine groups using fluorescein isothiocyanate (FITC) binding and efficient chemisorption of gold nanoparticles (AuNP) in order to identify the optimum conditions viz. dendrimer concentration, incubation time and dendrimer generation. While FITC binding showed a proportional increase in amine functional density with PAMAM concentration and time, interestingly the AuNP (40 nm) binding studies revealed the formation of loose PAMAM multilayers and their desorption. PAMAM (G4) concentration as low as 5 mM and incubation time of 24 h provide faster binding rate with densely packed AuNP and the RI sensitivity of ~15 (A546 nm/RIU). This simpler and inexpensive strategy could also be exploited for the development of functional PMMA substrates for various applications including nanotechnology, bio-imaging, drug delivery and analytical separations.

• 24.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Crack-junctions: Bridging the gap between nano electronics and giga manufacturing2018Doctoral thesis, comprehensive summary (Other academic)

Obtaining both nanometer precision of patterning and parallel fabrication on wafer-scale is currently not possible in conventional fabrication schemes. Just as we are looking beyond semiconductor technologies for next-generation electronics and photonics, our efforts turn to new ways of producing electronic and photonic interfaces with the nanoscale. Nanogap electrodes, with their accessible free-space and connection to electronic circuits, have attracted a lot of attention recently as scaffolds to study, sense, or harness the smallest stable structures found in nature: molecules. The main achievement of this thesis is the development of a novel type of nanogap electrodes, the so called crack-junction (CJ). Crack-junctions are unparalleled at realizing nanogap widths smaller than 10 nm and can be fabricated based exclusively on conventional wafer-scale microfabrication equipment and processes. These characteristics of crack-junctions stem from the sequence of two entirely self-induced steps participating in the formation of the nanogaps: 1./ a splitting step, during which a pre-strained electrode-bridge structure fractures to generate two new electrode surfaces facing one another, followed by 2./ a dividing step during which mechanical relaxation of the elastic strain induces displacement of these surfaces away from one another in a precisely controlled way. The positions of the resulting nanogaps are precisely controlled by designing the electrode-bridges with notched constrictions that localize crack formation. Based on the crack-junction methodology, two continuation concepts are developed and demonstrated. In the first concept, the crack-junction methodology is extended to electrode materials that are ductile, rather than brittle. This led to the development of a new type of break junction, the so called crack-defined break junction (CDBJ). In the second concept, the crack-defined nanogap structures realized by the crack-junction methodology are utilized as a shadow mask for the fabrication of single nanowire devices. The optical-lithography-compatible processes developed here to produce high-density arrays of individually-adjusted crack-junctions, crack-defined break junctions, and single-nanowire devices, provide viable solutions to bridge 10−9 nanoelectronics and 109 giga manufacturing.

• 25.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Scalable Manufacturing of Nanogaps2018In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 30, no 46, article id 1801124Article, review/survey (Refereed)

The ability to manufacture a nanogap in between two electrodes has proven a powerful catalyst for scientific discoveries in nanoscience and molecular electronics. A wide range of bottom-up and top-down methodologies are now available to fabricate nanogaps that are less than 10 nm wide. However, most available techniques involve time-consuming serial processes that are not compatible with large-scale manufacturing of nanogap devices. The scalable manufacturing of sub-10 nm gaps remains a great technological challenge that currently hinders both experimental nanoscience and the prospects for commercial exploitation of nanogap devices. Here, available nanogap fabrication methodologies are reviewed and a detailed comparison of their merits is provided, with special focus on large-scale and reproducible manufacturing of nanogaps. The most promising approaches that could achieve a breakthrough in research and commercial applications are identified. Emerging scalable nanogap manufacturing methodologies will ultimately enable applications with high scientific and societal impact, including high-speed whole genome sequencing, electromechanical computing, and molecular electronics using nanogap electrodes.

• 26.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Delft Univ Technol, Kavli Inst Nanosci, Lorentzweg 1, NL-2628 CJ Delft, Netherlands.. Delft Univ Technol, Kavli Inst Nanosci, Lorentzweg 1, NL-2628 CJ Delft, Netherlands.. Delft Univ Technol, Kavli Inst Nanosci, Lorentzweg 1, NL-2628 CJ Delft, Netherlands.. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Massively parallel fabrication of crack-defined gold break junctions featuring sub-3 nm gaps for molecular devices2018In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, article id 3433Article in journal (Refereed)

Break junctions provide tip-shaped contact electrodes that are fundamental components of nano and molecular electronics. However, the fabrication of break junctions remains notoriously time-consuming and difficult to parallelize. Here we demonstrate true parallel fabrication of gold break junctions featuring sub-3 nm gaps on the wafer-scale, by relying on a novel self-breaking mechanism based on controlled crack formation in notched bridge structures. We achieve fabrication densities as high as 7 million junctions per cm(2), with fabrication yields of around 7% for obtaining crack-defined break junctions with sub-3 nm gaps of fixed gap width that exhibit electron tunneling. We also form molecular junctions using dithiol-terminated oligo(phenylene ethynylene) (OPE3) to demonstrate the feasibility of our approach for electrical probing of molecules down to liquid helium temperatures. Our technology opens a whole new range of experimental opportunities for nano and molecular electronics applications, by enabling very large-scale fabrication of solid-state break junctions.

• 27.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Massively parallel fabrication of crack-defined gold break junctions featuring sub-3 nm electrode nanogapsIn: Article in journal (Refereed)
• 28.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Low-loss MEMS phase shifter for large scale reconfigurable silicon photonics2019Conference paper (Refereed)

We experimentally demonstrate a silicon MEMS phase shifter achieving more than π phase shift with sub-dB insertion loss (IL).  The phase is tuned by reducing the gap between a static suspended waveguide and a free silicon beam, via comb-drive actuation.  Our device reaches 1.2π phase shift at only 20 V, with only 0.3 dB insertion loss – an order of magnitude improvement over previously reported MEMS devices.  The device has a small footprint of 50×70 µm2 and its power consumption is 5 orders of magnitude lower than that of traditional thermal phase shifters.  Our new phase shifter is a fundamental building block of the next-generation large scale reconfigurable photonic circuits which will find applications in datacenter interconnects, artificial intelligence (AI), and quantum computing.

• 29.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Reducing Actuation Nonlinearity of MEMS Phase Shifters for Reconfigurable Photonic Circuits2019In: 2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), IEEE , 2019Conference paper (Refereed)

The low power consumption of MEMS actuators enables large-scale reconfigurable photonic circuits. However, insertion loss and actuation linearity need improvement. By simulations and experiments, we analyze the dominating design parameters affecting linearity and suggest improvements.

• 30.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Scalable Manufacturing of Single Nanowire Devices Using Crack-Defined Shadow Mask Lithography2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 8, p. 8217-8226Article in journal (Refereed)

Single nanowires (NWs) have a broad range of applications in nanoelectronics, nanomechanics, and nano photonics, but, to date, no technique can produce single sub 20 nm wide NWs with electrical connections in a scalable fashion. In this work, we combine conventional optical and crack lithographies to generate single NW devices with controllable and predictable dimensions and placement and with individual electrical contacts to the NWs. We demonstrate NWs made of gold, platinum, palladium, tungsten, tin, and metal oxides. We have used conventional i-line stepper lithography with a nominal resolution of 365 nm to define crack lithography structures in a shadow mask for large-scale manufacturing of sub-20 nm wide NWs, which is a 20-fold improvement over the resolution that is possible with the utilized stepper lithography. Overall, the proposed method represents an effective approach to generate single NW devices with useful applications in electrochemistry, photonics, and gas- and biosensing.

• 31.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Scalable fabrication of single nanowire devices using crack-defined shadow mask lithographyIn: Article in journal (Refereed)
• 32.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH. KTH. KTH. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
New dynamic silicon photonic components enabled by MEMS technology2018In: Proceedings Volume 10537, Silicon Photonics XIII, SPIE - International Society for Optical Engineering, 2018, Vol. 10537, article id 1053711Conference paper (Refereed)

Silicon photonics is the study and application of integrated optical systems which use silicon as an optical medium, usually by confining light in optical waveguides etched into the surface of silicon-on-insulator (SOI) wafers. The term microelectromechanical systems (MEMS) refers to the technology of mechanics on the microscale actuated by electrostatic actuators. Due to the low power requirements of electrostatic actuation, MEMS components are very power efficient, making them well suited for dense integration and mobile operation. MEMS components are conventionally also implemented in silicon, and MEMS sensors such as accelerometers, gyros, and microphones are now standard in every smartphone. By combining these two successful technologies, new active photonic components with extremely low power consumption can be made. We discuss our recent experimental work on tunable filters, tunable fiber-to-chip couplers, and dynamic waveguide dispersion tuning, enabled by the marriage of silicon MEMS and silicon photonics.

• 33.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Univ Ghent, Photon Res Grp, INTEC Dept, Imec, Technol Pk Zwijnaarde 15, B-9052 Ghent, Belgium.;Univ Ghent, Ctr Nano & Biophoton, Technol Pk Zwijnaarde 15, B-9052 Ghent, Belgium.. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Low-power optical beam steering by microelectromechanical waveguide gratings2019In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 44, no 4, p. 855-858Article in journal (Refereed)

Optical beam steering is key for optical communications, laser mapping (lidar), and medical imaging. For these applications, integrated photonics is an enabling technology that can provide miniaturized, lighter, lower-cost, and more power-efficient systems. However, common integrated photonic devices are too power demanding. Here, we experimentally demonstrate, for the first time, to the best of our knowledge, beam steering by microelectromechanical (MEMS) actuation of a suspended silicon photonic waveguide grating. Our device shows up to 5.6 degrees beam steering with 20 V actuation and power consumption below the mu W level, i.e., more than five orders of magnitude lower power consumption than previous thermo-optic tuning methods. The novel combination of MEMS with integrated photonics presented in this work lays ground for the next generation of power-efficient optical beam steering systems.

• 34.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligenta system, Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligenta system, Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligenta system, Micro and Nanosystems.
MEMS for Photonic Integrated Circuits2020In: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 26, no 2, p. 1-16Article in journal (Refereed)

The field of microelectromechanical systems (MEMS) for photonic integrated circuits (PICs) is reviewed. This field leverages mechanics at the nanometer to micrometer scale to improve existing components and introduce novel functionalities in PICs. This review covers the MEMS actuation principles and the mechanical tuning mechanisms for integrated photonics. The state of the art of MEMS tunable components in PICs is quantitatively reviewed and critically assessed with respect to suitability for large-scale integration in existing PIC technology platforms. MEMS provide a powerful approach to overcome current limitations in PIC technologies and to enable a new design dimension with a wide range of applications.

• 35.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligenta system, Micro and Nanosystems.
Scania Technical Centre. KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Integrated devices and circuits. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligenta system, Micro and Nanosystems. AMO GmbH. KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Integrated devices and circuits. KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Integrated devices and circuits. RWTH Aachen University; AMO GmbH. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligenta system, Micro and Nanosystems.
Suspended Graphene Membranes with Attached Silicon Proof Masses as Piezoresistive Nanoelectromechanical Systems Accelerometers2019In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, no 10, p. 6788-6799Article in journal (Refereed)

Graphene is an atomically thin material that features unique electrical and mechanical properties, which makes it an extremely promising material for future nanoelectromechanical systems (NEMS). Recently, basic NEMS accelerometer functionality has been demonstrated by utilizing piezoresistive graphene ribbons with suspended silicon proof masses. However, the proposed graphene ribbons have limitations regarding mechanical robustness, manufacturing yield, and the maximum measurement current that can be applied across the ribbons. Here, we report on suspended graphene membranes that are fully clamped at their circumference and have attached silicon proof masses. We demonstrate their utility as piezoresistive NEMS accelerometers, and they are found to be more robust, have longer life span and higher manufacturing yield, can withstand higher measurement currents, and are able to suspend larger silicon proof masses, as compared to the previous graphene ribbon devices. These findings are an important step toward bringing ultraminiaturized piezoresistive graphene NEMS closer toward deployment in emerging applications such as in wearable electronics, biomedical implants, and internet of things (IoT) devices.

• 36.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Scania Technical Centre. KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Integrated devices and circuits. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Senseair AB. AMO GmbH. Senseair AB. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Silex Microsystems AB, Järfälla, Sweden. KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Integrated devices and circuits. KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Integrated devices and circuits. RWTH Aachen University ; AMO GmbH. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Graphene ribbons with suspended masses as transducers in ultra-small nanoelectromechanical accelerometers2019In: Nature Electronics, ISSN 2520-1131, Vol. 2, no 9, p. 394-404Article in journal (Refereed)

Nanoelectromechanical system (NEMS) sensors and actuators could be of use in the development of next-generation mobile, wearable and implantable devices. However, these NEMS devices require transducers that are ultra-small, sensitive and can be fabricated at low cost. Here, we show that suspended double-layer graphene ribbons with attached silicon proof masses can be used as combined spring–mass and piezoresistive transducers. The transducers, which are created using processes that are compatible with large-scale semiconductor manufacturing technologies, can yield NEMS accelerometers that occupy at least two orders of magnitude smaller die area than conventional state-of-the-art silicon accelerometers. With our devices, we also extract the Young’s modulus values of double-layer graphene and show that the graphene ribbons have significant built-in stresses.

• 37.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Faculty of Electrical Engineering and Information Technology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany. Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, 09126 Chemnitz, Germany. Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, 09126 Chemnitz, Germany. Faculty of Electrical Engineering and Information Technology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, 09126 Chemnitz, Germany. Faculty of Electrical Engineering and Information Technology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany ; Gesellschaft für angewandte Mikro- und Optoelektronik mbH (AMO GmbH), Advanced Microelectronic Center Aachen, Otto-Blumenthal Str. 25, 52074 Aachen, Germany. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Direct observation of grain boundaries in graphene through vapor hydrofluoric acid (VHF) exposure2018In: Science advances, ISSN 2375-2548, Vol. 4, no 5, article id eaar5170Article in journal (Refereed)

The shape and density of grain boundary defects in graphene strongly influence its electrical, mechanical, and chemical properties. However, it is difficult and elaborate to gain information about the large-area distribution of grain boundary defects in graphene. An approach is presented that allows fast visualization of the large-area distribution of grain boundary–based line defects in chemical vapor deposition graphene after transferring graphene from the original copper substrate to a silicon dioxide surface. The approach is based on exposing graphene to vapor hydrofluoric acid (VHF), causing partial etching of the silicon dioxide underneath the graphene as VHF diffuses through graphene defects. The defects can then be identified using optical microscopy, scanning electron microscopy, or Raman spectroscopy. The methodology enables simple evaluation of the grain sizes in polycrystalline graphene and can therefore be a valuable procedure for optimizing graphene synthesis processes.

• 38.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
A Miniaturized Amperometric Hydrogen Sulfide Sensor Applicable for Bad Breath Monitoring2018In: Micromachines, ISSN 2072-666X, E-ISSN 2072-666X, Vol. 9, no 12, article id 612Article in journal (Refereed)

Bad breath or halitosis affects a majority of the population from time to time, causing personal discomfort and social embarrassment. Here, we report on a miniaturized, microelectromechanical systems (MEMS)-based, amperometric hydrogen sulfide (H2S) sensor that potentially allows bad breath quantification through a small handheld device. The sensor is designed to detect H2S gas in the order of parts-per-billion (ppb) and has a measured sensitivity of 0.65 nA/ppb with a response time of 21 s. The sensor was found to be selective to NO and NH3 gases, which are normally present in the oral breath of adults. The ppb-level detection capability of the integrated sensor, combined with its relatively fast response and high sensitivity to H2S, makes the sensor potentially applicable for oral breath monitoring.

• 39.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Investigation of Fabrication Accuracy and Repeatability of High-Q Silicon-Micromachined Narrowband Sub-THz Waveguide Filters2019In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 67, no 9, p. 3696-3706Article in journal (Refereed)

This paper investigates the fabrication accuracy and repeatability of micromachined quadruplet filters designed at a center frequency of 270 GHz with a 5-GHz bandwidth using a versatile multilayer chip platform which allows for axially arranged waveguide ports. A large number of narrowband silicon-micromachined filters arranged on multiple chips are investigated for fabrication imperfections, assembly misalignment, and fabrication yield, employing fabrication-prediction and different chip-to-chip self-alignment feature strategies. A numerical technique for characterization of the entire fabrication process of the filters through extracting the error statistics for coupling coefficients of a large number of different samples from separately assembled chips is proposed. A total of 47 test filters in effectively 15 different design variants have been fabricated in two fabrication runs, evaluated, and analyzed. The most critical sources of errors are determined. The expected accuracy of the entire filters fabrication process is demonstrated through the yield analysis based on the collected error statistics.

• 40.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Micromachined Filters at 450 GHz With 1% Fractional Bandwidth and Unloaded Q Beyond 7002019In: IEEE Transactions on Terahertz Science and Technology, ISSN 2156-342X, E-ISSN 2156-3446, Vol. 9, no 1Article in journal (Refereed)

This letter presents two silicon-micromachined narrowband fourth-order waveguide filter concepts with center frequency of 450 GHz, which are the first narrowband submillimeter-wave filters implemented in any technology with a fractional bandwidth as low as 1%. Both filters designs are highly compact and have axial port arrangements, so that they can be mounted directly between two standard waveguide flanges without needing any split-block interposers. The first filter concept contains two TM 110 dual-mode cavities of circular shape with coupling slots and perturbations arranged in two vertically stacked layers, while the second filter concept is composed of four TE 101 series resonators arranged in a folded, two-level topology without crosscouplings. Prototype devices are fabricated in a multilayer chip platform by high-precision, low-surface roughness deep-silicon etching on silicon-on-insulator wafers. The measured passband insertion loss of two prototype devices of the dual-mode circular-cavity filters is 2.3 dB, and 2.6 dB for three prototypes of the folded filter design. The corresponding extracted unloaded quality factors of the resonators are 786 ± 7 and 703 ± 13, respectively, which are the best so far reported for submillimeter-wave filters in any technology. The presented filters are extremely compact in terms of size; their footprints have areas of only 0.53 and 0.55 mm 2 , respectively, and the thickness between the waveguide flanges is 0.9 mm.

• 41.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Institut National des Sciences Appliquées de Rennes: Rennes, Bretagne, FR. Université de Rennes 1: Rennes, Bretagne, FR. CNRS Délégation Bretagne et Pays de Loire: Rennes, Bretagne, FR. Université de Rennes 1: Rennes, FR. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
A Low-Profile and High-Gain Frequency Beam Steering Subterahertz Antenna Enabled by Silicon MicromachiningIn: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221Article in journal (Refereed)

A very low-profile sub-THz high-gain frequencybeam steering antenna, enabled by silicon micromachining, is reported for the first time in this paper. The operation bandwidth of the antenna spans from 220 GHz to 300 GHz providing a simulated field of view of 56°. The design is based on a dielectric filled parallel-plate waveguide (PPW) leaky-wave antenna fed by a pillbox. The pillbox, a two-level PPW structure, has an integrated parabolic reflector to generate a planar wave front. The device is enabled by two extreme aspect ratio, 16 mm x16 mm large perforated membranes, which are only 30 μm thick, that provide the coupling between the two PPWs and form the LWA. The micromachined low-loss PPW structure results in a measured average radiation efficiency of −1 dB and a maximum gain of 28.5 dBi with an input reflection coefficient below −10 dB. The overall frequency beam steering frontend is extremely compact (24mm x 24mm x 0.9 mm) and can be directly mounted on a standard WM-864 waveguide flange. The design and fabrication challenges of such high performance antenna in the sub-THz frequency range are described and the measurement results of two fabricated prototypes are reported and discussed.

• 42.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Compact silicon-micromachined wideband 220 – 330 GHz turnstile orthomode transducer2018In: IEEE Transactions on Terahertz Science and Technology, ISSN 2156-342X, E-ISSN 2156-3446, Vol. 9, no 1, p. 38-46, article id 8542680Article in journal (Refereed)

This paper reports on a turnstile-junction orthomode transducer (OMT) implemented by silicon micromachiningin the 220 – 330 - GHz band. Turnstile OMTs are very widebandand allow for co-planar ports, but require accurate and complex geometries which makes their fabrication challenging at higher frequencies. The compact 10 mm x 10 mm x 0.9 mm OMT-chip presented in this paper is the first micromachined full-band OMT in any frequency range, and only the second turnstile OMT implemented above 110 GHz. The measured insertion loss(0.3 dB average, 0.6 dB worst-case) and the cross-polarization (60 dB average, 30 dB worst-case) over the whole waveguide band represent the best performance of any wideband OMT, regardless of design or fabrication technology, in the 220 –330 - GHz band. The return loss with 22 dB average (16 dB worst case) is comparable or better than previous work. The paper discusses design considerations and compromises of this complex 9 layer silicon micromachined device, including the influence of sidewall slopes, underetching, and post-bonding misalignment between the chips. It is shown that for a device which is very sensitive to geometrical variations, such as a turnstile OMT, it is necessary to anticipate and compensate for any fabrication imperfections in the design to achieve high RF performance.

• 43.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Wideband 220 – 330 GHz Turnstile OMT Enabled by Silicon Micromachining2018In: 2018 IEEE MTT-S International Microwave Symposium (IMS), Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1511-1514, article id 8439159Conference paper (Refereed)

This paper is the first publication on the first turnstile-junction orthogonal mode transducer (OMT) above110GHz, which is enabled by silicon micromachining. Incontrast to other OMT concepts, turnstile OMTs are wideband and allow for co-planar ports, but require accurate and complex fabrication and have therefore, to the best of our knowledge,not been implemented above 110GHz in any technology. As shown in this paper, the fabrication and assembly accuracy of silicon micromachining enables the realization of such complex OMT designs at 220 – 330GHz with excellent performance. The measured insertion loss is better than 0.7dB for the whole waveguide band, with mean values of 0.34dB and 0.48 dB for the vertical and horizontal polarizations, respectively. The measured return loss for both polarizations, even with an open ended common port, is better than 14dB for the whole waveguide band, and an average level of 18dB. An estimation of the worst-case cross-polarization level, derived from measurements, results in at least 20dB for the whole waveguide band, with an average of 25dB for the upper half of the band.

• 44.
Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Epinal Way, Loughborough, Loughborough University, LE11 3TU, UK.
KTH, School of Engineering Sciences (SCI), Applied Physics, Biophysics. Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW , UK. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW , UK. Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Epinal Way, Loughborough, Loughborough University, LE11 3TU, UK.
Measurement of protein binding with vastly improved time resolution using a quartz crystal microbalance driven at a fixed frequency2017Conference paper (Other academic)

Introduction: Quartz crystal microbalance (QCM) is commonly used to study biomolecular binding by measuring shifts in resonance frequency of a quartz-crystal-oscillator. However, the currently used methods like impedance analysis or QCM-D, which require repeated sweeps or ringing, are limited in time resolution (~1 second) due to the need for averaging. This restricts our ability to study transient biomolecular processes, which occur in sub-millisecond time scale. A novel technique has been reported here that allows quantification of resonance frequency of a quartz-crystal-oscillator with significantly improved time resolution by driving and measuring continuously at a constant frequency within the resonance bandwidth.

Method: The reactive component of the experimentally obtained impedance is utilized for the estimation of resonance frequency from the Butterworth Van-dyke (BVD) model of a quartz-crystal-oscillator, assuming that changes in motional inductance and capacitance around resonance are negligible. Triplicate sets of experiments involving the binding of streptavidin with a biotin functionalized 14.3 MHz quartz oscillator surface were performed. Intermittent frequency sweeps and fixed frequency drives, both of 0.1 second duration and around 14.3 MHz, were taken at intervals of 2 minutes under the flow of phosphate-buffer-saline (PBS buffer) before and after injection of streptavidin.

Results: The average shift in resonance frequency from the baseline (measurements before streptavidin injection) due to streptavidin-biotin binding, calculated from the fixed frequency drive or FFD (148 Hz) was within 1% of that estimated from the frequency sweep method by fitting the experimentally recorded impedance employing the BVD model (149 Hz).

Discussion: The agreement of the FFD with conventional frequency sweep method suggests that protein binding can be quantified with reasonable accuracy from each impedance data point, which with our set-up is recorded at 30 kHz sampling rate. This gives a time resolution of 0.03 millisecond, which is about 4 orders of magnitude improvement over the state-of-the-art.

• 45.
Centre for Biological Engineering, Loughborough University, Loughborough, UK.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Department of Chemistry, University of Cambridge, Cambridge, UK. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Department of Chemistry, University of Cambridge, Cambridge, UK. Centre for Biological Engineering, Loughborough University, Loughborough, UK.
Simple and ultrafast resonance frequency and dissipation shift measurements using a fixed frequency drive2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 281, p. 960-970Article in journal (Refereed)

A new method for determination of resonance frequency and dissipation of a mechanical oscillator is presented. Analytical expressions derived using the Butterworth-Van Dyke equivalent electrical circuit allow the determination of resonance frequency and dissipation directly from each impedance datapoint acquired at a fixed amplitude and frequency of drive, with no need for numerical fitting or measurement dead time unlike the conventional impedance or ring-down analysis methods. This enables an ultrahigh time resolution and superior noise performance with relatively simple instrumentation. Quantitative validations were carried out successfully against the impedance analysis method for inertial and viscous loading experiments on a 14.3 MHz quartz crystal resonator (QCR). Resonance frequency shifts associated with the transient processes of quick needle touches on a thiol self-assembled-monolayer functionalised QCR in liquid were measured with a time resolution of 112 μs, which is nearly two orders of magnitude better than the fastest reported quartz crystal microbalance. This simple and fast fixed frequency drive (FFD) based method for determination of resonance frequency and dissipation is potentially more easily multiplexable and implementable on a single silicon chip delivering economies of scale.

• 46.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Digital Electrical DNA Sensing2019Doctoral thesis, comprehensive summary (Other academic)

Molecule detection is a workhorse in life sciences and medicine, for example in cancer diagnosis and virus and bacterial detection. DNA analysis can provide vital information about the state of a host organism and its medical and health condition. A central challenge in DNA sensing lays in obtaining the following key detection characteristics in a single device: low limit of detection, small sample volume, high specificity, quantification, rapid time-to-result at a low cost.

Here we investigate whether direct electrical DNA sensing in a miniaturized detector can enable such performance. The detector consists of a gold-coated thin porous membrane, functionalized with oligonucleotides receptors, that is sandwiched between two off-stoichiometric thiol-ene-epoxy layers. The device works as follows. First, target DNA in the sample is specifically recognized by padlock probe hybridization and ligation. Second, the target-receptor circular molecules are amplified by rolling circle amplification (RCA), generating long ssDNA concatemers (RCP). Third, the RCPs are stretched through the membrane pores. Fourth, DNA metallization was used to form the gold nanowires bridging both sides of membrane pores after gold enhancement, which results in a conductive path that is measured with a simple resistance measurement. The thesis describes the engineering technology that enables low LoD detection of ssDNA using a digital measurement and details the development and optimization of the detector fabrication and operation, including structural design, materials, and microfluidic operation. We demonstrated a detector with sub-aM LoD, high specificity and simple operation in a miniaturized and uncomplicated format.

Furthermore, the thesis studies the long-term liquid storage in nL scale well arrays fabricated in off-stoichiometric thiol-ene (OSTE). We demonstrated liquid storage with < 10 % loss of stored PBS buffer for 33 days and the on-demand electrically controlled liquid release.

The thesis presents the potential of a combination DNA detector with the method of liquid storage. Combining the on-chip liquid storage and DNA detection methods could provide a powerful alternative to conventional bio-detectors used in molecular diagnostics, and improved performance in multiplexed point-of-care sensing of (ultra-low abundant) biomolecules.

• 47.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Stockholm Univ, Dept Biochem & Biophys, Sci Life Lab, Tomtebodavagen 23 A, SE-17165 Solna, Sweden. Stockholm Univ, Dept Biochem & Biophys, Sci Life Lab, Tomtebodavagen 23 A, SE-17165 Solna, Sweden. Stockholm Univ, Dept Biochem & Biophys, Sci Life Lab, Tomtebodavagen 23 A, SE-17165 Solna, Sweden. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Efficient DNA-assisted synthesis of trans-membrane gold nanowires2018In: Microsystems & Nanoengineering, ISSN 2055-7434, Vol. 4, p. 1-8, article id UNSP 17084Article in journal (Refereed)

Whereas electric circuits and surface-based (bio)chemical sensors are mostly constructed in-plane due to ease of manufacturing, 3D microscale and nanoscale structures allow denser integration of electronic components and improved mass transport of the analyte to (bio)chemical sensor surfaces. This work reports the first out-of-plane metallic nanowire formation based on stretching of DNA through a porous membrane. We use rolling circle amplification (RCA) to generate long single-stranded DNA concatemers with one end anchored to the surface. The DNA strands are stretched through the pores in the membrane during liquid removal by forced convection. Because the liquid–air interface movement across the membrane occurs in every pore, DNA stretching across the membrane is highly efficient. The stretched DNA molecules are transformed into trans-membrane gold nanowires through gold nanoparticle hybridization and gold enhancement chemistry. A 50 fM oligonucleotide concentration, a value two orders of magnitude lower than previously reported for flat surface-based nanowire formation, was sufficient for nanowire formation. We observed nanowires in up to 2.7% of the membrane pores, leading to an across-membrane electrical conductivity reduction from open circuit to o20 Ω. The simple electrical read-out offers a high signal-to-noise ratio and can also be extended for use as a biosensor due to the high specificity and scope for multiplexing offered by RCA.

• 48.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm. Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm. Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Direct Electrical Detection of sub-aM DNA concentrations2019Article in journal (Other academic)
• 49.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Technology. KTH, School of Biotechnology (BIO), Centres, Centre for Bioprocess Technology, CBioPT. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Formation of a thin-walled Spider Silk Tube on a Micromachined Scaffold2018In: Proceeding of 2018 IEEE 31st International Conference on Micro Electro Mechanical Systems (MEMS), Institute of Electrical and Electronics Engineers (IEEE), 2018, Vol. 2018, p. 83-85Conference paper (Refereed)

This paper reports on the first formation of a thin bio-functionalized spider silk tube, supported by an internal micromachined scaffold, in which both the inside and outside of the tube wall are freely accessible. The silk tube could potentially be used as an artificial blood vessel in an in vitro tissue scaffold, where endothelial cells and tissue cells can grow on both sides of the silk tube.

• 50.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
Capillary pumping independent of the liquid surface energy and viscosity2018In: Microsystems & Nanoengineering, ISSN 2055-7434, Vol. 4, no 2Article in journal (Refereed)

Capillary pumping is an attractive means of liquid actuation because it is a passive mechanism, i.e., it does not rely on an external energy supply during operation. The capillary flow rate generally depends on the liquid sample viscosity and surface energy. This poses a problem for capillary-driven systems that rely on a predictable flow rate and for which the sample viscosity or surface energy are not precisely known. Here, we introduce the capillary pumping of sample liquids with a flow rate that is constant in time and independent of the sample viscosity and sample surface energy. These features are enabled by a design in which a well-characterized pump liquid is capillarily imbibed into the downstream section of the pump and thereby pulls the unknown sample liquid into the upstream pump section. The downstream pump geometry is designed to exert a Laplace pressure and fluidic resistance that are substantially larger than those exerted by the upstream pump geometry on the sample liquid. Hence, the influence of the unknown sample liquid on the flow rate is negligible. We experimentally tested pumps of the new design with a variety of sample liquids, including water, different samples of whole blood, different samples of urine, isopropanol, mineral oil, and glycerol. The capillary filling speeds of these liquids vary by more than a factor 1000 when imbibed to a standard constant cross-section glass capillary. In our new pump design, 20 filling tests involving these liquid samples with vastly different properties resulted in a constant volumetric flow rate in the range of 20.96–24.76 μL/min. We expect this novel capillary design to have immediate applications in lab-on-a-chip systems and diagnostic devices.

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