Malleable Liquid-Metal-Coated Stretchable Electrospun Film for On-Skin Healthcare Monitoring, Joule Heating, and Electromagnetic Shielding

Abstract

Multifunctional flexible textile conductors, such as those capable of physiological signal detection, electromagnetic interference (EMI) shielding, and thermal management, are highly desirable for stretchable and wearable electronic devices, but there are still challenges in good performance and conformability on human skin. Liquid metals (LMs) possess ideal characteristics such as fluidity, high conductivity, and low toxicity, making them inherently soft and suitable for the fabrication of wearable biosensors. In this work, a multifunctional wearable liquid metal-coated stretchable olefin block copolymers (OBCs) film with high elasticity and conductivity, incorporating a three-dimensional conductive network, is developed for EMI shielding, motion monitoring, bioelectric monitoring, and Joule heating via an electrospinning method and spraying process. The OBCs film exhibited outstanding elasticity with a large elongation strain of 1560% and a high tensile strength of 0.48 MPa. The excellent conductivity of liquid metal endows the LM/OBCs with an outstanding EMI shielding performance of 69.38 dB; even after 1000 stretching cycles, the average EMI SE remains at 58.89 dB. Attributed to the high elasticity of the OBC, the prepared film exhibited a wide sensing range and fast response of 200 ms, indicating excellent motion monitoring capability. When employed for electrocardiography and electromyography, the LM/OBCs exhibited good conformability to skin and precise signal quality, outperforming commercial electrodes. Additionally, the Joule heating temperature of the LM/OBCs could be up to 71.9 °C at a low supplied voltage of 0.4 V. This work demonstrates that the stretchable LM/OBCs film suggests great potential for multifunctional smart textiles and flexible wearable electronics.