A highly conducting polymer for self-healable, printable, and stretchable organic electrochemical transistor arrays and near hysteresis-free soft tactile sensors

Abstract

A stretchable and self-healable conductive material with high conductivity is critical to high-performance wearable electronics and integrated devices for applications where large mechanical deformation is involved. While there has been great progress in developing stretchable and self-healable conducting materials, it remains challenging to concurrently maintain and recover such functionalities before and after healing. Here, we report a highly stretchable and autonomic self-healable conducting film consisting of a conducting polymer (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS) and a soft-polymer (poly(2-acrylamido-2-methyl-1-propanesulfonic acid, PAAMPSA). The optimal film exhibits outstanding stretchability as high as 630% and high electrical conductivity of 320 S/cm, while possessing the ability to repair both mechanical and electrical breakdowns when undergoing severe damage at ambient conditions. We further utilized this polymer composite film in a tactile sensor, which exhibits good pressure sensitivity of 164.5 kPa⁻1, near hysteresis-free, an ultrafast response time of 19 ms and excellent endurance over 1500 consecutive presses. Additionally, we successfully demonstrated an integrated 5 × 4 stretchable and self-healable organic electrochemical transistor (OECT) array with great device performance (including high transconductance of 12.95 ± 1.85 mS and good operational stability). The developed stretchable and autonomic self-healable conducting film significantly increases the practicality and shelf life of wearable electronics, which in turn, reduce maintenance costs and build-up of electronic waste.