Here is the abstract you requested from the CICMT_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Modelling and Characterization of Screen-Printed Metallic Electrothermal Microactuators|
|Keywords: Screen printed electrothermal microactuator, Free-standing thick film, Analytical and numerical thermomechanical simulati|
|MicroElectroMechanicalSystems (MEMS) such as thermal microactuators find applications in telecommunications, medical instrumentation, etc. It is well known that actuators based on the thermal expansion effect provide larger planar displacements and output forces than those using the electrostatic actuation mode. As polysilicon, metals have been investigated as potential materials for electrothermal, electromagnetic or piezoelectric actuators. In comparison to silicon microactuators, the larger thermal expansion coefficient of metallic devices gives rise to greater deformations for a same temperature difference. Therefore, a metal actuator can operate at lower temperature with lower power consumption. Recently, direct integration of RF MEMS structures on printed circuit board (PCB) has been achieved. An original extension of the standard screen-printing technology based on a sacrificial layer has been used for the fabrication of a metallic electrothermal microactuator. The actuator, screen-printed on a standard 96% alumina, consists of two linked copper beams of different widths partially suspended above the substrate to which they are anchored. Energy-dispersive X-ray analyses demonstrate the harmlessness of the process with regard to the metallic layer. Whilst increasing dc voltage between both anchors of the electrothermal microactuator, the deflection is optically measured using a calibrated CCD camera. The temperature distribution in the actuator is measured with an IR camera. In-plane deflections measurements are in relatively good agreement with analytical and numerical simulations. Moreover, theoretical and experimental results show that the buckling effect may lead to other possible applications for such thick-film metallic actuators. In addition, the thermal microactuator has been operated with an ac voltage, up to a frequency of 10Hz. The good physico-chemical characteristics of the microactuator and the agreement between functional properties and simulations, confirm the efficiency of this new sacrificial layer method for the fabrication of such microsystems. Compared to silicon, the metallic actuator offers the possibility of producing small deflections with large driving forces.|
|Patrick Ginet, Student
Université de Bordeaux