High-Performance and Degradable All-Paper-Based Pressure Sensor from Conductive Polymer

Cellulose paper has emerged as an ideal sensing element for wearable pressure sensors owing to its inherent flexibility, high porosity, and light weight. However, traditional paper-based pressure sensors use metal-based materials as electrodes, which significantly limits the unique advantages of paper, particularly in terms of degradability. In this study, a degradable pressure sensor is designed by combining the highly conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) Xuan paper electrode with a low-conductivity PEDOT:PSS tissue paper sensitive layer. Notably, Xuan paper, also called rice paper, has been a prominent substrate owing to its softness and good durability. By introducing a perforated structure in the sensitive layer, a novel sensing mechanism, conductivity conversion under pressure, is realized to improve the sensitivity. The obtained sensor exhibits a high sensitivity (13.9 kPa(-1) at < 8.3 kPa, 151 kPa(-1) at 8.3-20.8 kPa), ensuring that it can precisely monitor the full-range human activities. Additionally, as the sensor does not rely on metal materials, it can degrade in water or fire without causing any negative environmental impacts. These findings establish a new approach to producing highly sensitive degradable sensors, which hold significant potential for application in green electronics, paper-based sensing matrices, new prosthetics, and other fields.