Reduced Graphene Oxide-Based Flexible Pressure Sensors With Multiple Structural Designs

Flexible pressure sensors based on the piezoresistive mechanism hold great promise for emerging wearable applications. Structural engineering plays an integral role in the preparation of high-performance sensors. In this article, we design multiple structures in flexible piezoresistive sensors with a scalable and cost-effective method, in which reduced graphene oxide (rGO) serving as the conductive material is assembled onto two-layer interlocking frameworks made of pearl-patterned cotton towels (PPCTs), and porous laser-induced graphene (LIG) is selected as electrodes, and polystyrene microspheres (PSMSs) are filled into sensitive layers to act as the dielectric material. Benefited from the co-action of multiple structures, the sensor offers segmental sensitivities of 12.70, 1.10, and 0.18 kPa−1 over the range of 0-90 kPa, and there is a high linear sensitivity of 21.73 kPa−1 in the slight pressure range of 0-1 kPa. Through the detecting demonstration of a small object, the response and recovery time are estimated to be 120 and 60 ms. In addition, stability, durability, and reproducibility are proven to be qualified. At last, we preliminarily demonstrate the feasibility of potential wearable applications on detecting human body signals, ranging from pulses to muscle and joint activities.