A squared bossed diaphragm piezoresistive pressure sensor based on CNTs for low pressure range with enhanced sensitivity

Abstract

This paper presents Micro-Electro-Mechanical System (MEMS) diaphragm based piezoresistive pressure sensor for biomedical applications. A piezoresistive pressure sensor with a squared bossed diaphragm structure was developed for a low-pressure range. A trade-off between the deformation of the diaphragm and the stress induced in the piezo resistors on the diaphragm edge is analysis by using Carbon nanotubes (CNTs). CNTs are introduced in the sensor being a sensitivity material, responsible for wide range of pressure and sensitivity. The simulated results showed that the proposed structure was able to measure low pressure within range of 0–5 kPa with improved sensitivity and linearity. An 800-µm-wide 10-µm-thick square-diaphragm pressure sensor has also been designed and investigated for the different mender shape. It has been observed from the results that maximum sensitivity of 27.82 mV/kPa is achieved for 2-turn piezo resistor and the best non-linearity error − 0.27% FSS is achieved for 1-turn piezo resistor.