Highly Sensitive Differential Pressure Sensor With Bristled Cantilever Configuration Using a Silicon Piezoresistor on Polyimide Technique
Xin Ke, Zihao Dong, Peng Zhao, Zheng Gong, Tie Li, Deyuan Zhang, Huawei Chen, Yonggang Jiang
Abstract
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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.27\times 10^{-{5}}$ </tex-math></inline-formula> Pa <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula> 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.