Dual functional kirigami paper for simultaneously motion-monitoring and electrothermal heating

Flexible electronic devices are integral for meeting the diverse and complex requirements of wearable and multifunctional applications. Conductive papers with characteristics of light-weight, good processability, and degradability, offer significant benefits to wearable electronics. However, it often suffers from discontinuous distribution of the conductive network, inferior ductility, and conformability, which hinders its application. Herein, we present a conductive paper consisting of high-performance aramid paper as the matrix, and MXene and carbon nanotubes as the conductive fillers, fabricated through a mature papermaking technique and a kirigami design. The resultant dual functional kirigami paper (DFKP) exhibits desirable flexibility and breathability, excellent conductivity (1245.7 S/m), superior mechanical properties (tensile strength of 53.8 MPa), and ideal ductility (an elongation of ~ 612.1%), demonstrating promising capabilities in simultaneously wearable motion-sensing and electrical thermotherapy applications. The DFKP enables flexible deformation, better skin attachment, and three-dimensional (3D) supports for precise monitoring of physiological changes in response to different motions, featuring rapid response and recovery times as short as 30 ms. Furthermore, it exhibits a rapid temperature increase and reaches 95.3 °C within 35 s upon applying a voltage of 6 V. Remarkably, the DFKP proves stabilities under repeated deformations, maintaining a stable operational state even after 8000 cycles of stretching. Therefore, this unique wearable DFKP holds great promise for simultaneously being employed in human health monitoring and electrothermal therapy.