Direct write of a flexible high-sensitivity pressure sensor with fast response for electronic skins

Abstract

Abstract External tactile force/pressure sensing, as a vital function of electronic skins, is very important to robots in non-structured environments, intelligent prosthesis of the disabilities for baby care or daily life and medical cares, etc. Despite of great advance of pressure sensors for medium pressure (10–100 kPa), to achieve high sensitivity, good pressure resolution and fast response in electronic skins for applications in biomedicine, artificial prosthetics, personal health monitoring and robotics remains challengeable. Here we direct-wrote graphene nanoplatelets (GNPs) using Weissenberg effect on a PDMS substrate to fabricate a flexible pressure sensor with high pressure sensitivities about 6.56 MPa−1 and 0.335 kPa−1 respectively under the pressure less than 65 kPa and around 100 kPa. Minimum pressure change of ca. 14 Pa to the placement or removal of a tiny item can be detected. It is characterized to be of faster response/recovery speed (ca. 171 ms/110 ms), better repeatability and cycling stability, compared with most reported flexible medium-pressure sensor. The pressure electronic skin demonstrates good performance in its applications including pulse sensing on wrist and fingertip grabbing, indicating its greatly potential sensor candidate for electronic skins.