Falco Cornelius Marinus Jacobus Maria van Delft

Molecular Sense Ltd

A challenge of any biosensing technology is the detection of very low concentrations of analytes. The fluorescence interference contrast (FLIC) technique improves the fluorescence-based sensitivity by selectively amplifying, or suppressing, the emission of a fluorophore-labeled biomolecule immobilized on a transparent layer placed on top of a mirro...

Network-based biocomputation (NBC) relies on accurate guiding of biological agents through nanofabricated channels produced by lithographic patterning techniques. Here, we report on the large-scale, wafer-level fabrication of optimized microfluidic channel networks (NBC networks) using electron-beam lithography as the central method. To confirm the...

Network-based biocomputation (NBC) is an alternative, parallel computation approach that potentially can solve technologically important, combinatorial problems with much lower energy consumption than electronic processors. In NBC, a combinatorial problem is encoded into a physical, nanofabricated network. The problem is solved by biological agents...

All known algorithms to solve Nondeterministic Polynomial (NP) Complete problems, relevant to many real-life applications, require the exploration of a space of potential solutions, which grows exponentially with the size of the problem. Since electronic computers can implement only limited parallelism, their use for solving NP-complete problems is...

The high energy consumption of electronic data processors, together with physical challenges limiting their further improvement, has triggered intensive interest in alternative computation paradigms. Here we focus on network-based biocomputation (NBC), a massively parallel approach where computational problems are encoded in planar networks impleme...

Non-deterministic polynomial (NP-) complete problems, whose number of possible solutions grows exponentially with the number of variables, require by necessity massively parallel computation. Because sequential computers, such as solid state-based ones, can solve only small instances of these problems within a reasonable time frame, parallel comput...

The high energy consumption of electronic data processors, together with physical challenges limiting their further improvement, has triggered intensive interest in alternative computation paradigms. Here we focus on network-based biocomputation (NBC), a massively parallel approach that benefits from the energy efficiency of biological agents, such...

[This corrects the article DOI: 10.1098/rsfs.2018.0034.].

The invention relates to an apparatus and a method for the processing of single molecules, particularly for the sensing or sequencing of single-stranded DNA molecules, in particularly by using graphene nanopores.

One contribution of 10 to a theme issue 'Computation by natural systems'. On-chip network-based computation, using biological agents, is a new hardware embedded approach which attempts to find solutions to combinatorial problems, in principle, in a shorter time than the fast, but sequential electronic computers. This analytical review starts by des...

Significance Electronic computers are extremely powerful at performing a high number of operations at very high speeds, sequentially. However, they struggle with combinatorial tasks that can be solved faster if many operations are performed in parallel. Here, we present proof-of-concept of a parallel computer by solving the specific instance {2, 5,...

In recent years there has been increasing interest in the use of molecular motors and cytoskeletal filaments in nanotechnological applications, particularly in the production of biomedical microdevices. In order for this to be possible it is important to exert a high level of control over the movement of the filaments. Chemical patterning technique...

Human acetylcholinesterase (AChE) is a widely studied target enzyme in drug discovery for Alzheimer’s disease (AD). In this paper we report evaluation of the optimum structure and chemistry of the supporting material for a new AChE-based fluorescence sensing surface. To achieve this objective, multilayered silicon wafers with spatially controlled g...

The fabrication of electrode pairs with a small electrode gap separation using a focussed-ion-beam is reported. Using a previously developed technique, the gap between the electrodes was bridged using several benzenedimethanethiol molecules and a single gold nanoparticle. The electrical properties of this whole ensemble were measured and the result...

The natural environment of a living cell is not only organized on a micrometer, but also on a nanometer scale. Mimicking such a nanoscale topography in implantable biomaterials is critical to guide cellular behavior. Also, a correct positioning of cells on biomaterials is supposed to be very important for promoting wound healing and tissue regenera...

Recently, the first generation programmable Aperture Plate System with integrated CMOS electronics (CMOS-APS) featuring 43 thousand switchable beams has been inserted into a Charged Particle Nanopatterning (CHARPAN) tool. Using this configuration, the first (2D) exposure results in Hydrogen Silsesquioxane (HSQ) resist, employing 10 keV Hydrogen ion...

The fabrication of biomedical microdevices requires patterning techniques that can print structures ranging from hundreds of microns to sub-micron sizes, on large areas, with a low cost of ownership, and using essentially any material, but with relatively relaxed requirements for pattern precision. Addressing these specific needs and opportunities,...

To fight bone diseases characterized by poor bone quality like osteoporosis and osteoarthritis, as well as in reconstructive surgery, there is a need for a new generation of implantable biomaterials. It is envisioned that implant surfaces can be improved by mimicking the natural extracellular matrix of bone tissue, which is highly a organized nano-...

Substrate Conformal Imprint Lithography (SCIL™), developed within Philips Research, is a large area replication technology, which allows flexible nano-imprinting, even around defects. It uses templates (stamps) with a high modulus poly(dimethyl)siloxane (PDMS) pattern layer bonded onto a glass sheet with a low modulus PDMS intermediary layer. This...

Sputter deposited carbon has been tested as Reactive Ion Etching (RIE) intermediate, i.e. as second layer in a bi-layer resist system. E-beam written Hydrogen Silsesquioxane (HSQ) patterns or their reversed complementary (silicon) patterns (obtained by Chemical Mechanical Polishing (CMP)) were used as top layer. Using oxygen RIE, features smaller t...

A projection mask-less patterning (PMLP) proof-of-concept tool, realised as part of the European FP6-NMP integrated project CHARPAN (Charged Particle Nanotech), has been applied for three-dimensional patterning of a GaAs surface, using a stencil mask with a pre-defined opening distribution. A 10 × 10 matrix of micro-lenses was used as test structur...

Image reversal methods can be useful in those cases, where a resist of a specific tone is lacking particular desirable properties, e.g. etch resistance. Reversal of the image, e-beam written in Hydrogen SilsesQuioxane (HSQ), by a proper ‘work around’ method may result in a positive tone high resolution process with a high etch resistance, which is...

Nano-scale pattern templates have been manufactured in order to study the differences in cell behaviour between fibroblasts cultured on smooth and on grooved substrata. The pattern templates were made on silicon wafers using electron beam lithography in hydrogen silsesquioxane (HSQ) and subsequent reactive ion etching (RIE). These masters were repl...

The realization of complex three-dimensional structures at micro- and nanometre scale in various materials is of great importance for a number of micromechanical, microoptical, and microelectronic applications. Focused ion beam (FIB) patterning is one of the promising technologies for producing such three-dimensional structures utilizing layer-by-l...

The realization of complex three-dimensional structures at micro-and nanometre scale in various materials is of great importance for a number of micromechanical, microoptical, and microelectronic applications. Focused ion beam (FIB) patterning is one of the promising technologies for producing such three-dimensional structures utilizing layer-by-la...

The realization of complex three-dimensional structures at micro-and nano-meter scale in various materials is of great importance for a number of micromechanical, microoptical and microelectronic applications. Focused Ion Beam (FIB) patterning is one of the promising technologies for producing such 3D structures utilizing layer-by-layer fabrication...

The differences in morphological behaviour between fibroblasts cultured on smooth and nanogrooved substrata (groove depth: 5-350 nm, width: 20-1000 nm) have been evaluated in vitro. The aim of the study was to clarify to what extent cell guidance occurs on increasingly smaller topographies. Pattern templates were made using electron beam lithograph...

Patterns, e-beam written in hydrogen silsesquioxane (HSQ), have been reversed in tone by chemical mechanical polishing of silicon nitride deposited on top of these HSQ patterns. First, high-resolution patterns have been written in an 80 nm thick HSQ layer on a 6 in. silicon wafer. After development, 200 nm thick plasma enhanced chemical vapor depos...

Copolymers of methylmethacrylate (MMA) and trimethylsilyl-methylmethacrylate (SiMMA) in various molar ratios have been synthesised and characterised for use as a resist in electron beam lithography. The development procedure has been optimised in terms of contrast and surface roughness. Both the etch resistance during oxygen plasma etching and the...

In order to make model catalysts for fundamental research in heterogeneous catalysis, carrier oxide surfaces with well-defined properties are needed. Micro-contact printing has been used to make specific parts of a (hydroxylated) silicon oxide surface hydrophobic. The method comprises the e-beam writing of a master in hydrogen silsesquioxane (HSQ)...

Hydrogen silsesquioxane (HSQ) has been shown to behave as a negative tone inorganic e-beam resist with a resolution better than 20 nm established. In this article, delay-time and aging effects on contrast and sensitivity have been investigated. The effect of a 1 week delay in air between softbake and exposure is much larger than either the aging ef...

In most transition metals, steeply profiled nanoscale structures can not easily be obtained by dry etching, due to the redeposition of the etch products. An alternative method is presented here, which comprises the deposition of a plating base, electron-beam writing of nanoscale structures in negative tone hydrogen silsesquioxane resist, and electr...

Hydrogen SilsesQuioxane (HSQ) has previously been shown to behave as a high-resolution negative tone inorganic e-beam resist, giving single lines less than 10 nm wide. In this work, HSQ has been investigated for its applicability in photon-based lithographies. No measurable sensitivity has been observed for wavelengths of 800–400, 365, 248 and 193...

In this paper we present a new method for manufacturing steeply profiled grating structures composed of narrow lines and spaces embedded in transition metal layers. We focus on making EUV transmittive grating structures typically consisting of rectangular lines that are down to 40 nm wide, around 100 nm tall, up to 100 nm long, spaced at a 1-2 micr...

A bilayer resist system, consisting of hydrogen silsesquioxane (HSQ) as negative tone electron (e)-beam resist top coat and hard baked novolak resist as bottom coat, has been investigated for its ability to yield high aspect ratio nanoscale structures. For comparison, single layer HSQ (hard mask) has been investigated for its resolution, contrast,...

The negative tone resists NEB22 and UVN30 have been studied for their contrast and resolution in e-beam lithography, as well as in 248 nm DUV lithography. Also, their etch resistances have been determined in O2, SF6/He and CHF3/O2 plasmas in comparison with novolac resists. NEB22 shows a slightly higher resolution and higher contrasts and UVN30 sho...

A bilayer reist system developed by Olin Microelectronic Materials, consisting of a UV curable polystyrene bottom coat and a silicon loaded UV sensitive positive tone top coat (‘bamboo resist’), has been investigated for its sensitivity and resolution in electron beam lithography, and its etch selectivity during subsequent use in Reactive Ion Etchi...

Shipley's chemically amplified DUV resists UVN-2 (negative tone) and UV-5 (positive tone) have been studied for their high resolution capabilities in electron beam lithography. UV-5 is also capable of negative tone behaviour in case of e-beam overexposure. This effect is shown to be due to direct electron beam cross linking superimposed on the norm...

Previously, a mechanistic framework has been constructed for impact-assisted etch reactions in e.g. Reactive Ion Etching. The consecutive reaction steps (adsorption, surface reaction and product desorption) are assumed to be activated thermally and in parallel mechanically by fast particle impacts. The rate determining step in the etch mechanism de...

A 100 nm gate length power HEMT has been fabricated, which can be applied in power amplifiers throughout the millimeter-wave spectrum, as well as in very low noise amplifiers. This process permits amplification up to the W-band. The transistors are made using a double recess and an optimized epitaxial structure in order to maximize the breakdown vo...

In our previously developed mechanistic framework for dry etching, the three consecutive reaction steps (reactant chemisorption, surface reaction and product desorption) are assumed to be activated thermally and in parallel mechanically by fast particle impacts. According to this model, profiles with perpendicular side walls should be obtained if (...

A mechanistic framework is presented for impact assisted etch reactions. The consecutive reaction steps are assumed to be activated thermally and in parallel mechanically by fast particle impacts. The model explains the complicated temperature dependencies observed in dry etching and beam assisted etching, and it correlates the side wall profiles t...

Plasma etching of magnetic thin films is much more difficult than etching of silicon. A mechanistic framework has been constructed, which can explain why plasma etching of magnetic materials is, in many cases, restricted to low etch rates and oblique profiles.

The etch rates of CoNbZr and Fe/FeCrB soft-magnetic materials have been determined in an RF HCl plasma as a function of pressure. The bombardment energy flux towards the powered electrode and the surface temperature of the material being etched, are both dependent on applied power and pressure. At lower surface temperatures the etch mechanism is sh...

The surface compositions of Pt-Rh(100) and Pt-Rh(111) single-crystal surfaces were studied as a function of annealing temperature. It was found that both surfaces were enriched in platinum compared with the bulk platinum concentration. Relatively long annealing periods are required to reach the equilibrium concentration at low temperatures (< 950 K...

Using a deep submicron structuring process for oxide superconducting films, we have fabricated planar YBaâCuâOââ{sub δ}-Ag-YBaâCuâOâââ{sub δ} proximity junctions operating in the liquid nitrogen temperature region. Under microwave radiation Shapiro steps are generated in the current-voltage characteristic, in accordance with the resistively shunt...

A simple model is presented which relates bulk Debye temperatures to cohesive energy, atomic mass and atomic radius by means of a Lennard-Jones type of potential. Good agreement is obtained for the various groups of the periodic table. The model can be extended to describe surface Debye temperatures as well. It explains why the perpendicular surfac...

Previously a simple thermodynamical model has been derived which enabled to predict the growth mechanism (monolayer or crystallite growth) on the basis of the binding energy difference ΔE between an adsorbate in a monolayer and an adsorbate in the bulk of a crystallite. One of the consequences of this model is that the surface energy of the substra...

Previously a simple thermodynamical model has been derived which enabled to predict the growth mechanism (monolayer or crystallite growth) on the basis of the binding energy difference ΔE between an adsorbate in a monolayer and an adsorbate in the bulk of a crystallite. One of the consequences of this model is that the surface energy of the substra...

Glauconite, a natural three layer sheet silicate with Fe(II) and Fe(III) ions in octahedral positions, has been investigated by X-ray diffraction and Mössbauer spectroscopy after both hydrogen and oxygen treatments at ambient temperatures. The results show that in hydrogen up to 673 K Fe(III) ions are reduced to Fe(II) ions without any change in th...

The CO oxidation over silica supported Pt-Rh alloys was investigated and compared with the reaction over silica supported Pt and Rh catalysts. The CO-O2 ratio was varied from CO-rich to CO-lean conditions. The activity expressed as turnover frequency changes gradually with increasing Pt bulk concentration: from Rh-like to Pt-like. The results can b...

The influence of the initial surface composition of Pt-Rh alloy (410) single crystal surfaces on their reactivity towards O2, NO and CO has been investigated using AES, XPS and thermal reaction mass spectroscopy (TRMS). The initial surface composition was varied by a proper choice of the equilibration temperature in vacuum. The results show that th...

The reduction of NO by CO was investigated over various silica-supported Pt-Rh alloy catalysts. Steady state catalytic activity as a function of temperature was measured over a range of gas phase compositions. The results were compared with those obtained earlier for the CO + O2 reaction over the same catalysts. The results can be interpreted on th...

The use of Pt-Rh based three-way catalysts for automotive exhaust gas control stimulated us to study the surface composition and surface properties of various Pt-Rh alloy samples. In this paper we shall review our results concerning the relation of the surface structure and surface composition with the physical and chemical properties. The surface...

The use of Pt–Rh-based three-way catalysts for automotive exhaust-gas control stimulated us to study various Pt–Rh alloy surfaces: well defined single-crystal surfaces and SiO2-supported catalysts. For the sake of comparison data were also obtained for pure Pt and Rh single-crystal surfaces and catalysts. The surface composition and chemical proper...

Monte Carlo simulations of various binary alloy surfaces were performed in order to determine surface composition, composition depth profile and, in particular, the surface site distribution as a function of bulk composition, surface orientation and equilibration temperature. The influence of ordering was computed by varying the enthalpy of mixing...

AES has been used to investigate the variation of the surface composition of a polycrystalline Pt0.62-Rh0.38 foil with the equilibration temperature. The results show that an ultraclean surface exhibits a Pt enrichment that increases with increasing equilibration temperature from 80 to 89 at% Pt in the 800-1000 K range. In the range 1000-1500 K an...

The chemisorption and reactivity of oxygen, NO, CO and hydrogen on polycrystalline Pt, Rh, Pt0.55-Rh0.45 and Pt0.12-Rh0.88 alloy surfaces and on a Pt0.25-Rh0.75 (100) single crystal surface have been studied by AES. For Rh the results point to the presence of subsurface oxygen, following an exposure to 100 L O2 or NO at 290 K, under which condition...

It is shown that the surface composition of a binary alloy with known bulk composition can be determined by Auger Electron Spectroscopy, without calibrated reference spectra if an adsorbate is selectively chemisorbed on one of the constituent components. The correctness of the procedure is verified for Pt-Cu alloys using AES data obtained upon expo...

A simple thermodynamical model has been derived earlier, that enables to predict the growth mode (monolayer - or crystallite growth) for solid adsorbates on solid substrates. The influence of pseudomorphism on the model is discussed. It will be shown that the model can also be used for predicting the behaviour of liquids and gases on solid substrat...

A model based on that of Gallon is presented which describes the variations in the Auger electron spectroscopy intensities of the relevant elements for adsorbates growing on a substrate according to various growth mechanisms. The results are compared with experimental data from the literature.Our calculations predict that platinum deposited onto a...

The chemical characteristics and the reactivity of carbon on polycrystalline Rh and Pt surfaces towards hydrogen have been studied by Auger Electron Spectroscopy. Auger spectra of carbon on both metals have been subjected to spectrum subtraction techniques in order to reveal the chemical characteristics of it, as reflected by the fine structure of...

Selective chemisorption of ethene and the chemisorption induced surface segregation of Pt upon the chemisorption of ethene (and its subsequent decomposition) on Pt-Cu alloys have been studied by Auger electron spectroscopy. The experimental results have also been evaluated by computer simulations of the various possible processes upon the chemisorp...