# Highly Sensitive Oxidation‐Resistant Degradable Janus Piezoresistive Electronic Skin for Sustainable Wearable Electronics

## TL;DR

This paper introduces a biodegradable electronic skin that is highly sensitive, oxidation-resistant, and can detect a wide range of human movements, making it ideal for sustainable wearable electronics.

## Contribution

The novel contribution is a degradable, Janus piezoresistive e-skin with exceptional sensitivity, stability, and oxidation resistance using MXene and PEDOT:PSS on cellulose paper.

## Key findings

- The e-skin has ultrahigh sensitivity (19.27 kPa⁻¹) and a wide working range (0–40 kPa).
- It exhibits long-term stability (5,600 cycles) and oxidation resistance for over 22 days.
- The Janus wettability design enhances performance by having a hydrophilic contact surface and a hydrophobic external surface.

## Abstract

Wearable sensors enable fast and accurate monitoring of physiological signals, with broad applications in electronic skin (e‐skin), biomedical engineering, and human–machine interfaces. However, their proliferation raises concerns about electronic waste. To mitigate this waste, biodegradable polymers have been used to develop eco‐friendly sensors. However, various challenges persist, including low conductivity, limited sensitivity, and poor stability. We introduce a degradable cellulose paper e‐skin coated with Ti3C2Tx MXene and poly(3,4‐ethylenedioxythiophene)–polystyrene sulfonate (PEDOT:PSS) to overcome these challenges. The MXene/PEDOT:PSS‐coated cellulose paper piezoresistive e‐skin demonstrates ultrahigh sensitivity (19.27 kPa−1), a wide working range (0–40 kPa), linearity at low and high pressures, long‐term stability (5,600 cycles), and exceptional oxidation resistance (>22 days) owing to the stabilizing effect of PEDOT:PSS on MXene. In addition, the developed e‐skin has a hydrophilic contact surface with biological skin, and its external surface is highly hydrophobic, exhibiting Janus wettability that enhances its performance. Moreover, the e‐skin achieves high‐performance human motion monitoring by detecting both subtle and vigorous movements, such as joint flexions, vocal cord vibrations, and other motions. The developed piezoresistive e‐skin may find applications in diverse fields, such as human–machine interfaces, robotics, e‐skin, and wearable sensors by enabling precise and reliable stimuli detection.

This study presents a highly sensitive, oxidation‐resistant, biocompatible, and degradable Janus piezoresistive electronic skin for sustainable wearable electronics. The electronic skin exhibits sensitive and stable response across a broad pressure range, exceptional oxidation resistance, and Janus wettability. Its dual‐surface design enables accurate detection of diverse human motions, from subtle vibrations to vigorous joint flexions, enhancing wearable sensing applications.