Highly-stretchable liquid metal/nanofiber films for electromagnetic shielding interference, self-cleaning and temperature-visualizing

Abstract

Developing stretchable electromagnetic interference shielding (EMI) materials is remarkably desirable for integrated flexible electronic devices, because it often suffers from the decrease of EMI effectiveness (SE) under a large tensile deformation. Combining elastic polymers and liquid metal (LM) together may provide a promising solution. However, it still is a great challenge how to avoid the leakage of LM under the tensile deformation. Herein, the layer-by-layer thermoplastic polyurethane/liquid metal (TPU-LM) composite films with nanofiber-LM interlocked structure are prepared. The porous TPU nanofibers provide supporting skeleton with high mechanical properties to encapsulate LM to avoid its leakage, and the LM layers can therefore maintain continuous conductive network when it is stretched significantly. As a result, the TPU-LM composite film not only exhibits high EMI SE and anti-leakage performance under a large tensile deformation, but also presents excellent chemical resistance, high/low-temperature resistance (-196~100oC), self-cleaning and temperature-visualizing performances, which have a potential application in flexible wearable electronic devices with a large deformation. In short, the composite films with nanofiber-LM interlocked structure not only provide a promising solution to avoid the leakage of LM in practical applications, but also present the self-cleaning and temperature-visualizing multifunctional applications.