Laser-Induced Nanowire Percolation Interlocking for Ultrarobust Soft Electronics

Metallic nanowires have served as novel materials for soft electronics due to their outstanding mechanical compliance and electrical properties. However, weak adhesion and low mechanical robustness of nanowire networks to substrates significantly undermine their reliability, necessitating the use of an insulating protective layer, which greatly limits their utility. Herein, we present a versatile and generalized laser-based process that simultaneously achieves strong adhesion and mechanical robustness of nanowire networks on diverse substrates without the need for a protective layer. In this method, the laser-induced photothermal energy at the interface between the nanowire network and the substrate facilitates the interpenetration of the nanowire network and the polymer matrix, resulting in mechanical interlocking through percolation. This mechanism is broadly applicable across different metallic nanowires and thermoplastic substrates, significantly enhancing its universality in diverse applications. Thereby, we demonstrated the mechanical robustness of nanowires in reusable wearable physiological sensors on the skin without compromising the performance of the sensor. Furthermore, enhanced robustness and electrical conductivity by the laser-induced interlocking enables a stable functionalization of conducting polymers in a wet environment, broadening its application into various electrochemical devices.