Manual Activation of Metal‐Like Patterns in Leather for Stable Electrical Signal Transmission

Abstract Leather has emerged as a prevalent substrate in the realm of flexible electronics, owing to its distinctive breathability and robust structural stability. However, its intricate hierarchical structure presents obstacles in achieving strain‐insensitive, low‐resistance circuit patterns, thereby impeding the seamless integration of multifunctionality and precise electric signal transmission. In this study, eutectic gallium indium alloy (EGaIn) nanoparticles are successfully compounded with leather to create patterned metal‐like leather (MLL) through manual activation, eliminating the need for a mask. The resultant MLL has an electrical conductivity of 246 S m −1 , with conductive line widths ranging from 0.5 to 9 mm. Notably, after enduring 500 cycles of rigorous 150° folding and 10 000 cycles of polishing, it retains its exceptional electrical property. Furthermore, the MLL exhibits excellent air permeability and safety. These attributes empower it to detect physiological signals and maintain stable electric signal transmission. The development of MLL also lays the groundwork for the fabrication of multifunctional leather electronics.