Polymer matrix composite engineering for PDMS based capacitive sensors to achieve high-performance and broad-range pressure sensing

Abstract

Internet of Things (IoT) is increasingly set to be used and implemented in every sphere of technology where low-cost sensors, whose sensing needs are not so rigorous, are required for massive cost reduction. This article reports the fabrication of low-cost ZnO Nanoparticles incorporated Polydimethylsiloxane (PDMS)/Porous PDMS stack capacitive pressure sensor, which can be used for low, as well as high-stress monitoring applications. High-performance electrical and mechanical properties have been discerned with the proposed device structure. For a comparative study with conventional geometry, a porous PDMS sensor is also fabricated and characterized. The proposed sensor exhibits non-saturation behaviour even beyond 250 mmHg of the applied load. It also demonstrated the highest failure stress at 2.34 kgf/mm2, which could serve as an improvised replacement for other polymer layers under high-stress conditions. The sensitivity of the sensor is found to be 0.38 pF/cm2 mmHg at 12 mmHg applied pressure. The performance of the sensor, connecting to an embedded setup prototype involving microcontroller and other electrical components, was also demonstrated by placing objects in incremental order. These values give the proposed sensor high potential as fulfilling one of the vital requirement criteria in the IoT industry.