In this article the results of a numerical simulation of the thermal and mechanical properties of micromechanical sensors are described. Finite element analysis is used to model the response of the composite cantilever to temperature variations. The simulations consider triangular shaped cantilevers in air and water environments and under different configurations of thermal loading. The models utilize conditions from actual experiments which are conducted in parallel. Good agreement between numerical and experimental results studied so far allows us to use our numerical simulation to confidently predict the performance of the sensor under novel operating conditions and to optimize the sensor design for specific applications.