Wide range pressure sensing influenced by porous polymer using the sinking method

Abstract

Flexible pressure sensors have received attention because of their high sensitivity, durability, and flexibility, which can be used in many emerging applications in contrast to conventional pressure sensors based on rigid semiconductors and metallic foils. However, flexible pressure sensors are limited by complex, multistep, and expensive methods. In addition, these sensors exhibit a trade-off between sensitivity and the measured range of pressure. Hence, a simple method to produce a flexible pressure sensor with a wide range of detection is essential. In this study, nanocomposites were fabricated as flexible pressure sensors using a novel sinking process. Carbon nanotubes (CNTs) as fillers were sunk into a polydimethylsiloxane (PDMS) elastomer at various viscosities to form a homogenous CNTs/PDMS composite. Our results indicate that the decrease in viscosity of the PDMS elastomer increases not only the air bubbles inside the CNTs/PDMS composite but also the filler content. Our champion sensors have a sensitivity of 8.15 × 10–4 kPa−1, a recovery time of 0.15 s, and stability over 3000 cycles. Moreover, the sensor shows an ultra-wide sensing range, from the gripping of fingers to the weight of a sedan car, so it can meet the requirements for various practical applications.