Publications by Peter Ryser | EPFL Graph Search

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

A series of nanoporous membranes prepared from polyethylene-block-polystyrene were applied for size-selective diffusion of glucose and albumin molecules. Millimeter-sized test cells for characterization of such molecular diffusions were designed assuming a ...

We investigate in this work the fabrication of polymer micro-fluidic and micro-mechanical devices based on sublimable compounds as sacrificial layers, using a thick-film screen-printing deposition process. Fabrication of printed polymer microstructures featuring properties such as low cost, transparency and biocompatibility is particularly attractive and suitable for disposable biomedical devices. Channel, cavities and spacings for micro-devices are first defined by sacrificial material layers. This is foll

We present an in-depth analysis of the geometrical percolation behavior in the continuum of random assemblies of hard oblate ellipsoids of revolution. Simulations were carried out by considering a broad range of aspect-ratios, from spheres up to aspect-rat ...

Current low temperature electronics (175°C) for prolonged periods of time require packaging technologies that have to tackle many new problems. At high temperatures traditionally used materials such as organic circuit boards, adhesives and standard solders degrade rapidly or undergo changes in structure and pro

Micro solid-oxide fuel cells (μ-SOFCs) based on microfabrication processes are a promising alternative to batteries for supplying portable electronics, as very high energy densities may be achieved. However, a complete μ-SOFC module is a quite intricate structure, comprising 1) a gas-processing unit (GPU) to process a convenient energy source such as lighter gas into a more usable form, 2) the energy-generating cells proper, and 3) a post-combustor. The mechanical integration of these elements and their flu

A common problem when using piezoceramic actuators for precise positioning is their hysteresis. Either external sensors such as capacitive or inductive probes, optical sensors or strain gauges are commonly used. The latter are the most favorable solution in many cases, as they occupy the smallest volume and disturbances can mostly be avoided. Drawbacks are the assembly of these strain gauges on the target, their small gauge factor and their size. We propose a sensor based on thick-film technology which perm

To monitor high-frequency fluctuations of the equilibrium magnetic field in tokamaks, a 3D magnetic sensor has been developed. The sensor, which is positioned inside the vacuum vessel behind the protective tiles of the tokamak and is exposed to potential temperatures up to 400°C, is based on thick-film and LTCC (low-temperature co-fired ceramic) technology. To connect the sensor to the cabling that runs inside the vacuum vessel, mineral-insulated cables have to be brazed to the sensor to ensure electrical c

This paper presents the design and thermal characterization of a 15 × 22 mm2 LTCC module dedicated to the packaging of the elements of a miniature atomic clock. This module acts as a carrier for the components of the clock as well as temperature controller; this is particularly attractive since each component of the atomic clock requires precise and well defined working temperatures. For the thermal characterization of the designed module, various thermal simulations have been performed, by finite-element m

We investigate in the present work the fabrication of polymer-based micro-fluidic and micro-mechanical devices using sacrificial, resistive/conductive pastes, through a screen-printing process. An organic sacrificial paste is first screen-printed onto a su ...

Biogas is a fuel made from the anaerobic digestion of organic material to form methane. It can be used to power a stationary engine to generate electricity making it a viable method of decentralised power generation from renewables. However, biogas is a mixture of methane and carbon dioxide, and other trace gases such as hydrogen, hydrogen sulphide and oxygen. As such the quality can vary and setting the air-fuel ratio for efficient combustion can be problematic under these conditions. The Wobbe Index, or W

The continuing trend in the automotive and aviation industries to reduce complexity of electronic systems by removing cooling results in a need for high temperature electronics and associated packaging technologies. To ensure reliability over long periods of time the degradation of the packaging materials should be characterised. Epoxies show great promise as a reliable die attach solution for high temperature electronics due to their high bond strength, resistance to fatigue and chemical stability at tempe

The tunneling-percolation mechanism of conduction in disordered conductor-insulator composites is studied for a realistic continuum model where conducting and impenetrable spherical particles are dispersed in a three-dimensional continuum insulating materi ...

The resistivity dependence on temperature of composite resistors made of carbon fillers dispersed in an organic matrix are known to be strongly affected by the matrix thermal expansion. High positive temperature coefficient (PTC) effects, i.e. essentially switching from resistive to quasi-insulating behaviour, can be caused by phase changes in the matrix and the assorted volume expansion, a behaviour that has been previously shown with both simple organic waxes (low temperatures) and semicrystalline polymer

A new system combining a microreactor and a microcalorimetric chip was investigated. The small size of the microreactor channel permits maintaining isothermal conditions necessary for the kinetic characterization of highly exothermic reactions. These conditions are not easily obtained in classical calorimetric systems. The degree of mixing in the microchannel, which plays an important role for the characterization of fast reactions, was determined experimentally using an iodate–iodide system and confirmed b

We present a viscometric affinity biosensor for continuous monitoring of glucose in biological fluids such as blood and plasma. The sensing principle of this chemico-mechanical sensor is based upon the viscosity variation of a sensitive fluid with glucose ...

Ceramic technologies such as LTCC (Low Temperature Co-fired Ceramic) and thick-film are used widely in electronic circuits exposed to harsh environments, for applications in fields such as aerospace, automotive and energy exploration, where, owing to their ...

LTCC technology is based on sintering of multi-layered thick-film sheets (50-250 µm) or so-called green tapes, which are screen-printed with thick-film pastes such as conductors, resistors, etc. The terms low temperature and co-fired originate from the rel ...

The paper presents the European ACTS project “M2VTS” which stands for Multi Modal Verification for Teleservices and Security Applications. The primary goal of this project is to address the issue of secured access to local and centralised services in a multimedia environment. The main objective is to extend the scope of application of network based services by adding novel and intelligent functionalities, enabled by automatic verification systems combining multimodal strategies (secured access based on spee

The motivation of this study is the need for fundamental understanding of the effects of processing conditions on the electrical properties of low- temperature co-fired ceramic (LTCC) tapes, those screen printed with commercial thick-film pastes of electro ...

We noted that the tunneling-percolation framework is quite well understood at the extreme cases of percolation-like and hopping-like behaviors but that the intermediate regime has not been previously discussed, in spite of its relevance to the intensively ...

Peter Ryser

Chat with Graph Search

Size-Selective Diffusion in Nanoporous but Flexible Membranes for Glucose Sensors

Fabrication of polymer micro-devices based on organic sacrificial pastes

Percolative properties of hard oblate ellipsoids of revolution with a soft shell

Packaging technologies for high temperature control electronics

Ceramic modules for micro solid-oxide fuel cells

Integrated sensors for PZT actuators based on thick-film resistors

Solutions for thermally mismatched brazing operations for ceramic tokamak magnetic sensor

Thermal characterization of an LTCC module for miniature atomic clock packaging

Fabrication of Polymer-Based Micro Devices: Formulation and Study of the Paste

Validation of Novel Wobbe Index Sensor for Biogas Cogeneration

Characterisation of test vehicle for in-situ measurement of die attach thermal conductivity

Transport exponent in a three-dimensional continuum tunneling-percolation model

Tuneable PTC effect in polymer-wax-carbon composite resistors

A microreactor-based system for the study of fast exothermic reactions in liquid phase: characterization of the system

A viscosity-dependent affinity sensor for continuous monitoring of glucose in biological fluids

3D structuration of LTCC and related technologies for thermal management and microfluidic structures

Low temperature co-fired ceramic (LTCC) technology: general processing aspects and fabrication of 3-D structures for micro-fluidic devices

Multi Modal Verification for Teleservices and Security Applications

Influence of processing and conduction materials on properties of co-fired resistors in LTCC structures

Solution of the tunneling-percolation problem in the nanocomposite regime