Highly Sensitive Differential Pressure Sensor With Bristled Cantilever Configuration Using a Silicon Piezoresistor on Polyimide Technique

This article presents a novel silicon piezoresistor on polyimide (SPOP) technique for fabrication of differential pressure sensors (DPSs). Inspired by the bristled wing configuration of tiny wasps, a bristled polyimide (PI) cantilever was designed to detect the differential pressure caused by the aerodynamic loading on the surface of the cantilever. Compared with the conventional silicon-based DPS, the proposed DPS has a wide detection range, due to the large deformation of the flexible bristled cantilever and the enhanced leakage between the bristles. Boron-doped silicon was employed as the sensing material to improve the sensitivity of DPS. Experimental results indicate that the DPS has a high repeatability in the detection range of ±1000 Pa and exhibits sensitivity compression in high-pressure ranges. In addition, the sensitivity and resolution of the DPS are as high as $7.27\times 10^{-{5}}$ Pa $^{-{1}}$ and 0.32 Pa, respectively. Compared to other DPS, the cantilever-based SPOP-DPS exhibits a higher sensitivity in a wide detection range, resulting in promising applications.