Piezoresistive force sensor developed for use in handling of microparts

Micromechanical structures must be assembled where monolithic integration is not feasible because of incompatible processes, complex geometries or different materials involved. In the assembling process, the problem of measurement of small forces arises. This paper presents the development of a very sensitive piezoresistive force sensor with high linearity of the output signal. Sensor design considerations, optimisation of the geometry and the measurement results are presented. The inherent sensitivity of the piezoresistive sensors to temperature is strongly reduced by using the double bridge temperature compensation technique on the same chip.