Fingerprint-inspired graphene pressure sensor with wrinkled structure

Abstract

Nowadays, flexible pressure sensors have broad applications in healthcare monitoring, wearable electronics and so on. However, conventional fabrications are mostly time-consuming, complicated and even use toxic chemical reagents. It is in urgent need to fabricate pressure sensors with high sensitivity in a facile way. In nature, the fingertip skin of human has many epidermal ridges, which can sense small external stimuli. Here, inspired from the fingerprint, we propose a new type of pressure sensor made with reduced graphene oxide (rGO). The rGO film is designed to form a wrinkled structure by a facile stretching-releasing process, which mimics the morphology of fingertip skin. Owing to the fingertip-skin-like wrinkled structure, the pressure sensor exhibits high sensitivity of 5.77 kPa−1 (0 - 490 Pa). It also has a lot of attractive properties, such as fast response (< 100 ms), small detecting pressure (3 Pa) and good repeatability. We show the ability of the pressure sensor in small pressure detecting, human motion monitoring and motion pattern recognition. Furthermore, a translation system and a multi-touch device with spatially resolved detection based on the pressure sensor are developed. This pressure sensor is hopeful to have potential applications in wearable electronics and human–machine interaction systems.