Abstract
This PhD thesis deals with both study and fabrication of micro-accelerometers based on thermal convection. Under acceleration, convective heat transfer in a locally heated fluid is modified and induces a change in temperature profile. Using a fluid as seismic mass enhances better performances than traditional accelerometers in term of high shock reliability. One goal is to develop and characterize high-g accelerometers (> 10 000g). Besides, analytical studies carried out in parallel have allowed us to improve our understanding of fluid thermal behaviour. Effects of thermo-physical parameters, experimental set-up and sensor size on both sensitivity and bandwidth were deduced. On the other hand, a new concept of thermal detection based on the use of pyroelectric material was undertaken to improve sensor sensitivity as well as bandwidth. First the thin-film sputtering process is developed. Then the pyroelectric thermal accelerometer principle is confirmed.