Martinus Adela Maria Gijs

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We have measured the giant magnetoimpedance (GMI) of microstructured Co-based Metglas (R) 2714a amorphous magnetic ribbons. Before micropatterning, the amorphous ribbons were chemically thinned or polished, to study the influence of sample thickness and surface state on the GMI effect. The magnetic domain structure of polished foils near saturation is observed using the bitter fluid technique. The well-defined geometry of the samples allows a quantitative comparison of the GMI effect with a simple skin dept

Fast spreading of antimicrobial resistance is now considered a major global health threat. New technologies are required, enabling rapid diagnostics of bacterial infection combined with fast antimicrobial susceptibility testing (AST) for evaluating the eff ...

We have designed and realised a new type of microsystem for the electrical characterisation of arrays of living cells for biomedical diagnostic purposes. We have used deep plasma etching for the fabrication of microholes and micro-fluidic channels in silicon substrates. After oxidation and electrical contact fabrication, these structured silicon wafers have been anodically bonded with Pyrex wafers. The fabrication is completed by the gluing of micro-patterned polyimide foils on top of the silicon. We have t

A new method to realize arrays of micro-lenses using a sol gel glass replication technology is presented. Polydimethyl-siloxane (PDMS) master structures are used for the replication of thin glass membranes, which, by an appropriate annealing procedure, result in converging lenses with positive meniscus. Hereby, we exploit PDMS - sol gel surface interactions and thickness dependent changes in composition of the sol gel solution. The lenses are realized on a circular and square like basis. We characterize the

We propose a new approach for magnetic microbead transport in microfluidic channels over long-range distances by the actuation of a simple array of planar coils. The latter are placed in a uniform static magnetic field, generated by permanent magnets. This static field imposes a magnetic moment with a fixed sense to the microbeads. As a consequence, the magnetic energy and the magnetic forces acting on the beads are strongly enhanced, when the beads are placed in a spatially varying field. Only the very sma

We study the droplet-based synthesis of fluorescent silica nanoparticles (50–350 nm size) in a microfluidic chip. Fluorescein-isothiocyanate (FITC) dye is first chemically linked to aminopropyl triethoxysilane (APTES) in ethanol and this reaction product i ...

We investigate the analytical performance of an interdigitated electrode sensor for the label-free detection of DNA, by monitoring the complex impedance of 5 µm wide interdigitated Pt microelectrodes on a glass substrate. We detect the hybridization of unl ...

We present a novel technological approach for the in situ realization of a micron-thin poly-acrylamide membrane in the center of a microfluidic channel. The membrane is formed by interfacial polymerization of an inner stream of monomer solution in between ...

We demonstrate a method to determine the Brownian motion and the diffusion coefficient of a nanoparticle in water in a plane that is parallel to a solid boundary and as function of the distance normal to that boundary by using an optical tweezers instrumen ...

We propose a novel versatile method for the rapid and low-cost fabrication of microsphere arrays to be used as lenses of desired geometry and optical properties. Our method is based on the electrostatic self-assembly of dielectric microspheres in Parylene-C/glass well templates, with the array geometry patterned in the Parylene-C layer via standard clean room techniques. While different particle sizes and materials can be used to tune the light focusing properties of the microlenses, we demonstrate here a p

We present the rapid fabrication of custom protein micro-arrays, in less than 35 minutes, on the surface of immobilized beads using microchannel-guided flows driven by a single syringe pump. The commercially available beads provide robust micro-array surfa ...

We form water-in-oil droplets in a microfluidic channel-nozzle geometry for studying the influence of viscosity of oil and of different oil classes on the droplet size. We find that the chemical structure of oil dominates over its viscosity. Our studies ar ...

This paper presents a simple and low-cost prototyping technology for the realization of integrated micropumps in polymethylmethacrylate (PMMA). The three-dimensional (3D) micropumps consist of stacks of structured PMMA layers, which are either realised with precision milling tools for the more complex parts, or fabricated using the powder blasting technique for channel-type structures. We integrate silicone membranes into the chip to realize check-valves or use dynamic diffuser valves. We use two different

We have developed a novel batch-type technology for making three-dimensional (3-D) millimeter-sized transformers for ultrasmall low-power (0.1 to 1 Watt) applications. The technology uses the 3-D micropatterning of ferrite wafers by powder blasting to form the magnetic cores of the inductive devices, and combines these cores with electrical windings made by flex-foil printed circuit board technology. Microfabrication and assembly of the parts can be done in a batch process on a wafer/foil level, opening the

In this paper, we demonstrate a bead-based microfluidic immunoassay using self-assembled streptavidin-coated bead micropatterns. The beads are assembled on the microfluidic channel surface using electrostatic forces between the negatively-charged streptavi ...

We introduce a microfluidic platform for automated on-chip worm culture, creation of synchronized embryo microarrays, and long-term parallel live imaging of Caenorhabditis elegans embryos. Our device allows studying well-defined embryo populations at unprecedented spatio-temporal resolution, via fully automated multi-dimensional imaging, covering six independent dimensions: the 3 spatial coordinates, development time, exposure duration/type (brightfield, fluorescent), and embryo number in the microarray. We

We have fabricated two-dimensional inductive devices by integrating micropatterned magnetic foils of high permeability (µr=100000) with winding patterns realised in printed circuit boards (PCBs) and flex-foil technology. We realise relatively high inductances of 1-10 µH for transformer type devices and a sensitivity of 60 V/T at 30 kHz for fluxgate magnetic induction sensing devices. The same type of device is also used as a current sensor; here we typically find sensitivities of 10 mV/A for excitation curr

Progress in understanding lower hybrid current drive (LHCD) at high density has been made through experiments and modeling, which is encouraging given the need for an efficient off-axis current profile control technique in burning plasma. By reducing the w ...

In this paper we describe the two-dimensional (2D) magnetic manipulation of aqueous droplets suspended in silicone oil over the chip surface. The magnetic actuation is based on the force imposed on superparamagnetic microparticles inside the droplets. Thes ...

We present a hybrid CMOS based microsystem where magnetic actuation of microparticles is combined with integrated optical detection via Single Photon Avalanche Diodes (SPADs). The system’s configuration permits the manipulation and detection of single magn ...

Martinus Adela Maria Gijs

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Giant magnetoimpedance of chemically thinned and polished magnetic amorphous ribbons

Fast antimicrobial susceptibility testing onEscherichia coliby metabolic heat nanocalorimetry

Fabrication of a novel microsystem for the electrical characterisation of cell array

Micro-replication of Optical Lenses in Glass using Sol Gel Technology

Planar coil-based microsystem for the long-range transport of magnetic beads

Controlled synthesis of fluorescent silica nanoparticles inside microfluidic droplets

Label-free detection of DNA with interdigitated micro-electrodes in a fluidic cell

In situ fabrication of a polyacrylamide membrane in a microfluidic channel

Study of constrained Brownian motion of nanoparticles near an interface using optical tweezers

Electrostatic self-assembly of microsphere lens arrays

Microchannel-guided capture antibody patterning on beads for multiple protein detection arrays

Influence of Oil Type and Viscosity on Droplet Size in a Flow Focusing Microfluidic Device

Plastic micropumps using ferrofluid and magnetic membrane actuation

Batch-Type Millimeter-Size Transformers for Miniaturized Power Applications

Sandwich immunoassay on a microfluidic chip using patterns of electrostatically self-assembled streptavidin-coated beads

Multi-dimensional imaging and phenotyping of C. elegans embryos via an automated microfluidic device

A hybrid technology for miniaturised inductive device applications

Review of recent experimental and modeling advances in the understanding of lower hybrid current drive in ITER-relevant regimes

Two dimensional magnetic manipulation of microdroplets on a chip

Particle Shadow Tracking - Combining Magnetic Particle Manipulation with In-Situ Optical Detection in a CMOS Microsystem