Porous Elastomer Film with Controlled Liquid‐Metal Distribution for Recyclable Highly Customizable and Stretchable Patterned Electronics

Abstract

Abstract Stretchable conductors with conductive patterns are crucial for flexible electronics, which demand high conductivity and stable electrical properties under significant deformations. Liquid‐metal (LM)‐based composites patterned by selective sintering are promising for flexible electronics, however, short‐circuiting may occur due to unintended activation of unsintered regions under strain. Hence, developing highly customizable LM‐based stretchable conductors remains a persistent challenge. Stretchable LM/thermoplastic polyurethane (TPU) porous films are designed with controlled LM distribution through non‐solvent‐induced phase separation and surface modification of LM particles, which overcomes the limitations of conventional LM‐based stretchable composites and enables the design of diverse flexible electronics with conductive patterns via imprinting. The porous structure increases spacing between LM particles and alleviates stress on LM particles, ensuring electrical insulation of the unimprinted regions during stretching. The customizable patterning process enables the films to be used for electromagnetic interference (EMI) shielding, and stripe patterns allow for dynamic tuning of EMI shielding performance. Additionally, they demonstrate excellent performance in wireless communications, tunable EM wave filters, and stretchable Joule heaters. Moreover, the solubility of TPU makes it easy to recycle LM from the film, thus demonstrating ideal recyclability. Outstanding electrical stability and versatile applications guarantee its significant impact on stretchable electronics.