Design, fabrication and testing of reduced graphene oxide strain gauge based pressure sensor with increased sensitivity

Pressure sensors with high sensitivity, repeatable output, wide sensing range, suitable for mass production and which can be manufactured cost effectively are highly desirable for pressure sensing applications. Over the years Graphene and rGO (reduced graphene oxide) based strain gauges have typically been prepared on substrates such as silicon, polydimethylsiloxane, polyethylene terephthalate, kapton, and rubber. They have mainly been utilized in the wearable and temperate condition applications. In the proposed work we would like to present a stainless steel based pressure sensor using rigid centre diaphragm and a fixed guided beam along with rGO-filter paper based strain gauges (reduced graphene oxide on a cellulose filter paper). The resulting strain on the fixed guided beam due to the applied pressure is sensed by the rGO-filter paper based strain gauges and the output is measured as change in resistance. The analytical, numerical simulation and experimental studies of this sensor are discussed and the results obtained are in good agreement to each other. The performance of the sensor is evaluated experimentally and is compared against a standard strain gauge for a pressure range of 0 to 20 bar. The developed sensor exhibits a pressure sensitivity of 2.29 Ω/bar, with an enhanced gauge factor of 112 and the effect of temperature is nullified. The high sensitivity and a wide sensing range enable it for a broad variety of applications.