Porous silicon as new micro material for actuated 3D flip-up structures and its applications in microoptics

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The interactions between large collections of settling snowflakes and various turbulence intensity levels within the air column make snow precipitation difficult to forecast. Characterizing the multi-scale spatial distribution and transport of snowflakes is crucial for understanding the spatial modulations in the snow deposition process and for interpreting remote sensing signals. In this work, we perform large-scale three-dimensional tracking of snowflakes falling through the atmospheric surface layer in t

Time reversal is an established wave imaging and focusing method that has proved to be robust and compatible with super-resolution imaging and focusing, i.e., to provide images and foci with subwavelength features beyond the diffraction limit. The method has been applied to numerous wave systems. We propose a systematic review of super-resolution time reversal applied to electromagnetic waves in the radio-frequency regime. We examine the theoretical foundation, the methods and the applications of radio-freq

In this project, we study the problem of reconstructing parametrized fonts from scanned images. In the first part, we investigate high-resolution noise-free images. In the second part, we study the noisy images, where artefacts such as low-resolution and blurry edges come into play. We present the quad-tree spline fitting method to robustly reconstruct parametrized fonts in the presence of print-scan artefacts.

To preserve the speed advantage of Fourier Domain detection in Optical Coherence Microscopy (OCM), extended depth of field is needed. With a narrow probing volume that extends over a long axial range, tissue could be measured in vivo and at cellular resolution. To assess and improve the DOF and the lateral resolution, we analyzed the coherent transfer function (CTF) of OCM. Both the illumination and detection optics contribute equally to the overall imaging performance. In the Fourier domain detection, each

We have developed a hybrid scanning probe microscopy sensor consisting of a SU-8 body and full platinum cantilever and tip. The fabrication process is based on surface-micromachining of a silicon wafer, where oxidation sharpened moulds define the tip shape, giving tips with a radius sharper than 20 nm. With optimized sputter deposition parameters we obtained fully straight platinum cantilevers after release. The release is based on a dry isotropic silicon under-etching. Platinum shows biocompatibility, maki

In many applications, the sampling frequency is limited by the physical characteristics of the components: the pixel pitch, the rate of the A/D converter, etc. A low-pass filter is then often applied before the sampling operation to avoid aliasing. However, when multiple copies are available, it is possible to use the information that is inherently present in the aliasing to reconstruct a higher resolution signal. If the different copies have unknown relative offsets, this is a non-linear problem in the off

Wafer scale nanostencil lithography is used to define 200 nm scale mechanically resonating silicon cantilevers monolithically integrated into CMOS circuits. We demonstrate the simultaneous patterning of ~2000 nanodevices by post-processing standard CMOS wafers using one single metal evaporation, pattern transfer to silicon and subsequent etch of the sacrificial layer. Resonance frequencies around 1.5 MHz were measured in air and vacuum and tuned by applying dc voltages of 10V and 1V respectively.

We aim to fabricate stencils with apertures in the sub-micron range

Two methods to fabricate artificial nanoscale mechanical devices are presented. One is based on the combination of local Ga+ doping of silicon by a focused ion beam and KOH etching. The second is based on the use of nanostencil as miniature shadow mask to define metal nanowires that are subsequently underetched. Both method allow for rapid prototyping of novel NEMS elements having resonance frequencies up to several 100s MHz, and have distinct characteristics in terms of material properties. Method 1: Selec

Ease of fabrication and design flexibility are two attractive features of low temperature co-fired ceramics (LTCC) technology for fabrication of complex micro-fluidic devices. Such structures are designed and processed using different shaping methods, the extent and complexity of which depends on the final device specifications (dimensions, mechanical and functional properties). In this work, we propose a sacrificial layer method based on carbon-black paste, which burns out during the LTCC firing stage. The

In current tokamaks and, in particular, in future larger devices such as ITER, the control of neo-classical tearing modes (NTM) is essential for achieving high performance in terms of the beta limit. A commonly used scheme for NTM stabilization consists in driving a helical current at the resonance surface of interest with electron-cyclotron-current-drive. Depending on the ratio between the magnetic island size and the RF beam width, complete stabilization of the NTM will only be achieved with deep RF power

NOVELTY - A micro-electro-mechanical-system (MEMS) is manufactured by the use of a sacrificial layer that is made of silicon. USE - The invention is used in surface micromachining for the manufacture of a MEMS containing a suspended metal layer or MEMS device architecture. MEMS device is a suspended gate metal oxide semiconductor field effect transistor (SG-MOSFET). It is used as radio-frequency capacitive switch, current switch, radio-frequency tuneable capacitor, magnetic field sensor, accelerometer, and

All-fiber optical phase modulators were fabricated by coating standard telecommunication optical fibers with thin films of piezoelectric ZnO. Piezoelectric optical fiber coatings of PbZrxTi1-xO3(PZT) were also produced, and the actuation capability necessary for making optical fiber modulators is demonstrated. Both the ZnO and the PZT fiber coatings were deposited by reactive direct current magnetron sputtering of metal targets. The geometry of the sputtering system, fiber rotation, and reactive sputtering

Porous silicon as new micro material for actuated 3D flip-up structures and its applications in microoptics

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Large-scale Clustering of Natural Snowfall: Collective Precipitation Dynamics in Three Dimensions

Radio-frequency Subwavelength Time-reversal Imaging and Focusing: A Review of Theory, Methods, and Applications

Reverse Digital Typography

Coherent transfer functions and extended depth of field

Novel full platinum nanoprobes suitable for biological SPM experiments

Aliasing is Good for You: Joint Registration and Reconstruction for Super-Resolution

Full wafer integration of NEMS on CMOS by nanostencil lithography

FABRICATION OF NANOAPERTURES ON STENCILS USING FOCUSED ION BEAMS FOR SHADOW MASK EVAPORATION

Methods for rapid prototyping of nanomechanical (NEMS) devices

Fabrication of LTCC Micro-fluidic Devices Using Sacrificial Carbon Layers

Power modulation capabilities of the 140 GHz/1 MW gyrotron for the stellarator Wendelstein 7-X

Manufacture of micro-electro-mechanical-system using sacrificial layer made of silicon, useful for micro-electro-mechanical-system device architecture, e.g. radio-frequency capacitive switch and current switch

Sputter deposited piezoelectric fiber coatings for acousto-optic modulators