Publications by Philippe Renaud

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Structures of very high aspect ratio which are mechanically stiff in the substrate direction and flexible in the direction parallel to the substrate are studied. Such structures can be exploited to produce thermal flexure actuators which are capable of large motion produced by thermal expansion. The magnitude of the deflection depends strongly on geometry and material properties. Structures fabricated by laser micro-machining are characterized and compared to numerical simulations.

Microstereolithography is a technology at the interface of the microengineering and rapid prototyping domains. It has evolved from the stereolithography technique, and is also based on a light-induced layer- stacking manufacturing, As the resolution of the microstereolithography technique is far better than the one of rapid prototyping technologies, this technique is of particular interest in the microengineering domain where its 3D capability allows the production of components no other microfabrication te

In this paper we analyse a new type of silicon strain sensor based on the piezo- tunneling effect in a silicon lateral backward diode. The implantation profiles of the junction have been optimised to obtain a prevailing tunneling current at the reverse biased operating point. The optimisation was performed using a two- dimensional simulation of the fabrication process. The simulated profiles have been used for the numerical determination of the current flow in the structure. The experimental results clearly

Novel cooling systems with very low material budget are being fabricated and studied. They consist of silicon wafers in which microchannels are etched and closed by bonding another wafer. This cooling option is being considered for future HEP detectors of ...

A novel Silicon Sacrificial Layer Dry Etching (SSLDE) technique using sputtered amorphous or LPCVD polycrystalline silicon as sacrificial layers and a dry fluorine-based (SF₆) plasma chemistry as releasing process is reported with a detailed experimental study of the release etching step. The process is capable of various applications in surface micromachining process, and can be applied in fabricating RF MEMS switches, tunable capacitors, high-Q suspended inductors and suspended-gate MOSFETs. The developed

The use of low-stress SU8 nanocomposites as a functional material for micro- parts and coating applications is described in this paper. It was found that the nanoparticles lower the internal stress and decrease the wear rate and frictional coefficient of t ...

Detailed investigations of the limits of a new negative-tone near-UV resist (IBM SU-8) have been performed. SU-8 is an epoxy-based resist designed specifically for ultrathick, high-aspect-ratio MEMS-type applications. We have demonstrated that with single-layer coatings, thicknesses of more than 500 km can be achieved reproducibly. Thicker resist layers can be made by applying multiple coatings, and we have achieved exposures in 1200 IJ-m thick, double-coated SU-8 resist layers. We have found that the aspec

In this paper, a new microstereolithography apparatus is described. It is an integral process in which a complete layer can be made in one exposure only, in contrast to vector-by-vector processes which are based on the vectorial tracing of each layer. As for most microstereolithography processes, complex objects can be realized by superimposing layers, each layer being obtained by a light-induced polymerization of a liquid resin. The vertical and transverse resolution of the process we are developping have

Microfluidic channels obtained by SU-8 photolithography and filled with liquid scintillators were recently demonstrated to be an interesting technology for the implementation of novel particle detectors. The main advantages of this approach are the intrins ...

Vascularization arguably poses the most significant hurdle for the success of most biomaterials-based tissue engineering therapies. In this work, we report two printing strategies that permit the 3D Inkjet printing of fluorescent alginate hydro gels into o ...

This paper presents a remotely powered implantable heart monitoring system for freely moving animals. The system measures the blood pressure in the left ventricle of the heart and transmits the data to a database unit. The implanted unit is remotely powere ...

In this work, we present theoretical and experimental studies of nanofluidic channels as a potential biosensor for measuring rapid protein complex formation. Using the specific properties offered by nanofluidics, such as the decrease of effective diffusion ...

The invention describes a method for producing hybrid microelectronic/microfluidic sensors at industrial scale. The method is characterized in that it comprises the following steps for obtaining said microfluidic channel: a) a first lamination step of a dr ...

We report on recent advances in micro fabrication technology using micromolding and high aspect ratio structuring of photopolymer. The direct application is the realization of components for millimeter-size, ultrasonic piezoelectric motors. A new fabrication process using a thick epoxy-based material (SU-8) and the electroplating of nickel is demonstrated. Photopolymer structures have also been realized and released using a positive tone resist as sacrificial layer. The main advantages over past fabrication

This paper describes the development of a polyimide/SU-8 catheter-tip MEMS gauge pressure sensor. Finite element analysis was used to investigate critical parameters, impacting on the device design and sensing characteristics. The sensing element of the device was fabricated by polyimide-based micromachining on a flexible membrane, using embedded thin-film metallic wires as piezoresistive elements. A chamber containing this flexible membrane was sealed using an adapted SU-8 bonding technique. The device was

We report on recent advances in micro fabrication technology using micromoulding and high-aspect ratio structuring of photopolymer. The direct application is the realization of components for millimeter-size, ultrasonic piezoelectric motors. A new fabrication process using a thick epoxy-based material (SU-8) and the electroplating of nickel is demonstrated. Photopolymer structures have also been realized and released using a positive tone resist as sacrificial layer. The main advantages over past fabricatio

For the development of micro gas sensors, studies of field ionization and break-down in small gaps were performed. A finite element simulation was done for an estimate of the achievable field strength near a nanotube tip in small gaps. The simulation also ...

This paper reports on a new microfluidic device for temperature stimulation of cell in in-vitro culture. Micro- electrodes in a meander shape are embedded into the microfluidic channels to generate either a temperature gradient through the culture chamber ...

In this paper an innovative micromachined passive flow regulator for implantable drug delivery systems is presented. The aim is to passively achieve a constant flow rate over a certain pressure range through linear variation of a flow resistance. This flow regulator is based on bending membrane contact with a micromachined substrate. A first serie of samples has been realized using standard Silicon micromachining. For better biochemical performances, a second version of the device has been manufactured in T

A connector for providing both a fluidic and electrical connection is disclosed, said connector having a proximal end, a distal end and an elongated body in between, characterized in that the elongated body has an inner cavity spanning throughout its lengt ...

Philippe Renaud

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Modelization and characterization of asymmetrical thermal micro-actuators

Microstereolithography: a review

Optimisation of a new strain sensor based on the piezo-tunneling effect

Low material budget microfabricated cooling devices for particle detectors and front-end electronics

Silicon sacrificial layer dry etching (SSLDE) for free-standing RF MEMS architectures

Effect of filler behavior on nanocomposite SU8 photoresist for moving micro- parts

High-aspect-ratio, ultrathick, negative-tone near-UV photoresist and its applications for MEMS

Microstereolithography: a new process to build complex 3D objects

Scintillation detectors based on silicon microfluidic channels

High-Fidelity Printing Strategies for Printing 3D Vascular Hydrogel Structures

Remotely powered implantable heart monitoring system for freely moving animals

Detecting proteins complex formation using steady-state diffusion in a nanochannel

Microfluidic sensor and method for obtaining such a sensor

Fabrication process of high aspect ratio elastic and SU-8 structures for piezoelectric motor applications

Polyimide/SU-8 catheter-tip MEMS gauge pressure sensor

Two steps micromoulding and photopolymer high-aspect ratio structuring for applications in piezoelectric motor components

Study of gas ionization schemes for micro devices

Temperature gradient stimulation for cell division in C. Elegans Embryos on chip

Passive micro-flow regulator for drug delivery system

Tip connector for fluidic and electrical connection