Incorporating Nanoparticles in Porous Foam Templating for Enhanced Sensitivity of Capacitive Pressure Sensors

• Published in: Advanced Sensor Research Vol. 3; no. 5
• Main Authors: Kurup, Lekshmi A., Arthur, Joshua N., Cole, Cameron M., Suresh, Sinduja, Timm, Jana, Marschall, Roland, Yambem, Soniya D.
• Format: Journal Article
• Language: English
• Published: Wiley-VCH 01.05.2024
• Subjects: capacitive pressure sensors; graphene coated foams; porous foam pressure sensors
• ISSN: 2751-1219; 2751-1219
• DOI: 10.1002/adsr.202300149

Capacitive pressure sensors based on porous foams have been demonstrated for various biomedical applications (0–10 kPa). Many different methods for fabricating porous foams have been reported. In this work, for the first time, the incorporation of silica nanoparticles are reported into the templating process of porous foams fabricated through a combination of particle and emulsion templating, in order to enhance the formation of smaller microstructures in polydimethylsiloxane foams. The foams are coated with graphene, and pressure sensors developed using these foams showed increased sensitivity, up to 4.08 kPa−1. The incorporation of nanoparticles also improves the linearity of the sensitivity, giving a linear sensitivity for the pressure sensors over a pressure range of 0–6 kPa. Further, these pressure sensors have a low limit of detection of ≈13 Pa. These results indicate that incorporation of suitable nanoparticles in the templating of foams is a promising strategy for developing foam‐based pressure sensors with high and linear sensitivity. This work introduces the incorporation of silica nanoparticles (SNPs) in the templating process of porous foams for capacitive pressure sensors. The SNPs change the microstructures and porosity of the foams, which results in significant enhancement of sensitivity for pressures below 2 kPa, leading to linearization of sensitivity of the pressure sensor in the pressure range of 0–6 kPa.