Jean-Claude Jeannot

Miniaturized pH biosensors based on electrochemically modified electrodes with biocompatible polymers.

Potentiometric pH sensors based on linear polyethylenimine (L-PEI) and linear polypropylenimine(L-PPI), two synthetic enzymes and biocompatible polymers, films were prepared by electropolymerization of three different monomers: ethylenediamine (EDA), 1,3-diaminopropane (1,3-DAP) and diethylenetriamine (DETA) in order to be used in clinical, dermatological and biological applications, such as in vivo analysis. In a first step a biosensor was tested which consisted in a platinum wire protruded from glass sheath. The polymer film coated on these platinum electrodes showed good linear potentiometric responses to pH changes from pH 3 to 10. Resulting electrodes present both good reversibility and good stability versus time. The effect of the different polymer film thicknesses to potentiometric responses was also studied. This study allowed us to develop a miniaturized pH biosensor in the second step. This sensor was fabricated using photo-lithography, followed by sputtering and lift-off processes, and it included an electronic detection system. We have also successfully studied the potentiometric responses to pH changes of this device over a period of 1 month, and so we propose this new pH micro-biosensor as an alternative to classical pH sensors currently used in dermatology.

A micromachined connector for the coupling of optical waveguides and ribbon optical fibers

This paper describes in details the fabrication and tests of a micromechanical connector, which is used for the precise optical self-alignment of multi-waveguide optical integrated circuits (OIC) to ribbon optical fibers, without injecting light in the fiber. Nickel alignment pins are electrodeposited on the OIC using a photolithographic process, and these pins are inserted into suitable openings made on a silicon micromachined platform, on which optical fibers are accurately positioned using V-grooves. A simultaneous fabrication of several microstructures which are used as an assistance for the assembly of the fibers and the waveguides is presented for the first time. Design and fabrication issues are reported, as well as preliminary experimental results which show that excess optical losses on the order of 3 dB per coupling facet can be obtained.

Microconnectors for the passive alignment of optical waveguides and ribbon optical fibers

This paper describes the fabrication of a new mechanical microconnector, which is used for the precise optical self-alignment of multi-waveguide Optical Integrated Circuits (OIC) to ribbon optical fibers, without injecting light in the fiber. Nickel alignment pins are electrodeposited on the OIC using a photolithographic process, and the pins are inserted into suitable openings made on a silicon micromachined platform, on which optical fibers are accurately positioned using V-grooves. Design and fabrication issues are reported, as well as preliminary experimental results which show that excess optical losses on the order of 3 dB can be obtained.

A micromechanical focusing device for artificial vision

The design, fabrication and measured characteristics of a bulk-micromachined focusing device are presented. A micro-bench is formed by 2 V-grooves which support an optical fiber and a micro-lens. A thermal actuator is integrated in the optical bench, and allows a micro-lens to be moved along the optical axis in order to adjust longitudinally its focusing spot. This device can be used for vision systems such as robotic vision or confocal microscopy. The focusing range can be adjusted between 50 mm and infinity with a 15 mA supply current.