Analytical modelling of the transient response of thermopile-based MEMS sensors

This work presents an analytical model dedicated to study of the transient response of multipurpose MEMS devices based on thermopile sensors. In general, thermopile sensors response depends on ambient temperature, thermal conductivity of the gas inside the housing and the pressure of the gas. The presented model takes into account all these parameters. This model was sucessfully implemented for the study of transient behaviour of our multifunctional sensors with p+Si/Al thermocouples and a bulk micromachined bilayered membrane. Simulations were performed for different gases of interest and conclusions were deduced regarding the influence of relevant parameters on the thermal time constant. This analytical approach is general and flexible enough to be implemented for analysis of the transient behaviour of thermopile-based sensors when used for different applications.