Graphene Porous Foams for Capacitive Pressure Sensing

• Published in: ACS applied nano materials Vol. 5; no. 2; pp. 2973 - 2983
• Main Authors: Kurup, Lekshmi A, Cole, Cameron M, Arthur, Joshua N, Yambem, Soniya D
• Format: Journal Article
• Language: English
• Published: American Chemical Society 25.02.2022
• Subjects: conductive foam; sugar templating; flexible pressure sensor; capacitive pressure sensor; graphene porous foam
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.2c00247

Flexible pressure sensors are an attractive area of research due to their potential applications in biomedical sensing and wearable devices. Among flexible and wearable pressure sensors, capacitive pressure sensors show significant advantages, owing to their potential low cost, ultralow power consumption, tolerance to temperature variations, high sensitivity, and low hysteresis. In this work, we develop capacitive flexible pressure sensors using graphene based conductive foams. In these soft and porous conductive foams, graphene is present either as a coating of the pores in the foam, inside the structure of the foam, or as a combination of both. We demonstrate that they are durable and sensitive at low pressure ranges (<10 kPa). Systematic analysis of the different pressure sensors revealed that the porous foams with graphene coated pores are the most sensitive (∼0.137 kPa–1) in the pressure range 0–6 kPa, with a limit of detection of 50 Pa. Further, we demonstrated the potential applications of our pressure sensors by showing detection of weak physiological signals of the body. Our work is highly relevant for research in flexible pressure sensors based on conductive foams as it shows the impact of different ways of incorporating conductive material on performance of pressure sensors.