Surface-micromachined flexible polysilicon sensor array

Abstract

A flexible polysilicon strain gauge array has been realized using surface micromachining with SiO2 sacrificial layer. The realized sensor array is mechanically flexible, which can be attached on nonplanar surfaces. To realize the flexible strain gauge, a new packaging scheme using polysilicon/oxide based surface-micromachining was developed. The proposed packaging scheme completes the strain sensors and the circuit board on a single process, which eliminates additional assembly and alignment problems. The measured gauge factor shows that it is more sensitive than metal strain gauge. Unlike a single-crystal silicon strain gauge, the proposed polysilicon gauge does not have any limitations in the direction of strain.