Adjusting Sensitivity And Linearity Of The Wearable Pressure Sensors By An Arbitrary Micro-Protuberance Structure Of Polyvinylidene Fluoride/Reduced Graphene Oxide Dielectric Films

Flexible pressure sensors with high sensitivity over a broad linear range and fast response have extension applications in wearable electronics. Herein, we prepared a tunable capacitive pressure sensors based on arbitrary micro-protuberances geometry films via low-cost soft lithography, employing the polyvinylidene fluoride/reduced graphene oxide (PVDF/rGO) composite with a high dielectric constant of 172 and low loss tangent of 0.48. The hierarchical microstructures' different sizes endow the sensors adjustable pressure response, achieving the regulation of sensitivity and linear detection range. The superior microstructured film-based sensor exhibits a high sensitivity (1.19 kPa(-1)) over 20 times that of the bulk film, wide linearity (1.3 kPa), a rapid response (43 ms), a low limit of detection (10.6 Pa), and remarkable durability over 5000 compression/release cycles. In addition, based on the excellent sensing performance above-mentioned, the device is successfully employed in the scenario of monitoring pressure interaction and human activities by mounting on different parts of the human body or object. This work provides a means to optimize the sensor's sensitivity and linearity by hierarchical structure and contributes to its wearable electronic applications.