An ultrasensitive flexible pressure sensor for multimodal wearable electronic skins based on large-scale polystyrene ball@reduced graphene-oxide core–shell nanoparticles

Abstract

In this study, we report the fabrication of a flexible film-shaped resistive-type pressure sensor with high performance and versatile applications by sandwiching a polystyrene ball@reduced graphene-oxide (PS ball@rGO) core–shell nanomaterial film layer between two thin flexible polydimethylsiloxane (PDMS) sheets. The preparation of materials and the fabrication processes of the sensor devices are simple, efficient, and economical. The detection limit of the PS ball@rGO-based pressure sensors can be as low as 3 Pa with a low energy consumption of ∼1 μW at a low bias voltage of 1 V; moreover, these sensors exhibit a short response time of 50 ms with a high sensitivity of 50.9 kPa⁻¹ at 3–1000 Pa and high stability even after 20 000 loading–unloading cycles. In addition, different applications of our flexible sensor in detecting blood pulse, swallowing, skin pulling, and articular activities were demonstrated when the sensor was attached to the human body. Furthermore, by an efficient scalable fabrication process, a large-area integrated pressure sensor array was demonstrated, and it enabled patterning of the mapped spatial pressure distribution as well as large-area monitoring of body pressure, pulses, and human actions.