Development and characterization of a novel nanocomposite-polymer based piezoresistive pressure sensor for low-pressure application

This work presents the design, fabrication and characterization of a nanocomposite-polymer (piezoresistive) based pressure sensor for low-pressure measurement. The developed piezoresistive pressure sensor consists of a PDMS diaphragm and piezoresistor sensing element. The sensing element is made of PDMS/Graphite composite, which works as a piezoresistor active element. The ultrasonic mixing followed by degasification, spin coating and curing is used to fabricate the PDMS diaphragm and PDPM/Graphite piezoresistive composite. The characterization of the pure PDMS and PDMS/Graphite composite with different graphite filler concentrations is done before assembling them to fabricate the pressure-sensing device. The PDPM/Graphite composite shows a higher elastic modulus compared to the pure PDMS and the electrical conductivity of the composite also increases with the increment of the graphite filler in it. After the characterization of the constituents of the pressure sensing device, the device is characterized for low-pressure sensing.