Abstract: This communication reports on the localized growth of carbon nanotubes (CNTs) on the surface of classical micro-hotplates with integrated heater and transducing electrodes. A catalytic thermal CVD process has been developed and adapted to grow CNTs by only using the heat provided by the integrated heater. Spatial control of the CNTs' growth was achieved thanks to this method; CNTs are localized only on the heating area of the micro-hotplate, and electrical contact with the integrated electrodes can be obtained. The influence of the catalyst, gas flow, and temperature cycles on the growth of CNT was investigated in order to optimize growth and avoid micro-hotplate degradation. Different strategies were investigated to get the electrical connection between the CNTs and the platinum electrodes. The electrically connected grown CNTs could be used directly as gas-sensitive resistors with superior performance in terms of sensitivity than metal–oxide gas sensors integrated on such platforms.
Abstract: he book "Doped Nanomaterials and Nanodevices" summarizes research activities into the fundamental properties and applications of doped nanomaterials. Much attention has been focused on nanomaterials in order to take advantage of their unique properties resulting from quantum size confinement and surface effects. Quantum size confinement affects the energy structure and physical properties of doped nanomaterials and nanodevices. Luminescence phenomena are being investigated extensively in doped nanoparticles, with the hope of finding applications in optical storage, radiation detection, infrared detection, and dosimetry. Near-infrared and upconversion luminescence nanoparticles are particularly promising for biological imaging because auto-fluorescence can be overcome and higher imaging resolutions can be obtained. Doped insulator nanomaterials including carbon nanotubes represent a new type of high-efficiency luminescent material. As a new kind of biological labeling agent, insulator nanoparticles are less toxic than semiconductor nanoparticles and are promising for cancer detection, diagnosis, and treatment. Doped nanomaterials are expected to make significant contributions to nanotechnology for practical applications in the fields of electronics, photonics, optics, homeland security, and medical sciences. The book contains state-of-the-art review chapters focused on different aspects of doped nanomaterials and their based nanodevices. The book has been divided into three volumes.
Abstract: This paper reports on a new component which allows a mechanical position to be accurately detected. This component is a magnetically actuated microswitch fabricated in MEMS technology. Unlike the well-known Reed or Hall switches components this magnetic microswitch offers all of the following advantages: (1) a powerless sensor, (2) a highly integrated sensor (less than 3 mm3), (3) an electrical isolation (dry contact) (4) a high position accuracy (no component dispersion), (5) an easy implementation in real applications, thanks to a well verified analytical model. Position detection accuracy of the sensor as well as electrical and reliability tests results are reported.
Abstract: This paper reports on the reliability issues encountered during the development of a dry ohmic switch fabricated in MEMS technology. Particularly, focus is made on electrical contact reliability. Contact degradation during hot switching tests has been noticed, and leads to switch lifetime limitation. In order to understand this phenomenon, characterizations have been performed on damaged switches and degradation modes have been cleary identified. Solutions have been implemented and finally the Schneider Electric MEMS switch is able to switch 5 V/1 mA loads for several millions of cycles and 14 V/10 mA loads for several 104 of cycles.
Abstract: This communication reports on the localized growth of carbon nanotubes (CNTs) on the surface of micro-hotplates with integrated transducing electrodes. A catalytic thermal CVD process has been adapted to grow CNTs by only using the heat provided by the integrated heater. Few groups have already reported such a CNT growth on a micro-heater but our work differs on the point that we use a classical micro-hotplate to locally grow CNTs on integrated electrodes to electrically contact the CNTs. These platforms are fabricated using conventional IC and specific microsystem processes and are used in resistive metal oxide gas sensors. They can reach within milliseconds and at low power a temperature up to 900degC. The influence of the catalyst, methane flow, and temperature cycles on the growth of CNT was investigated. Different strategies were investigated to get the electrical connection between the CNTs and the platinum electrodes. The concept proposed is to replace the metal-oxide layer by a network of gas-sensitive CNT integrated onto the micro gas sensing platform.
