LM/PAN films with high thermal conductivity and excellent shielding performance for wearable electronics and devices

Abstract Materials with combined electromagnetic shielding and efficient thermal management functions are in high demand due to the rapid growth of electronic devices with excessive heat accumulation and electromagnetic interference. This work proposes a unique preparation strategy combining solution blow spinning, spraying and hot pressing to develop multi-layered liquid metal (LM)/polyacrylonitrile (PAN) films with well-disperse LM nanodroplets on PAN) fiber films. The in-plane thermal conductivity of the films reached 7.768 and 3.623 W·m−1·K−1 along the thickness direction, indicating 80 and 58 times higher than that of pure PAN film, respectively. The high thermal conductivity quickly dissipated the generated heat by electronic devices, helping address the issue of heat accumulation. In the X-band (8.2–12.4 GHz), the shielding effectiveness (SET) of the films was as high as 79.52 dB to effectively block electromagnetic wave interference. Based on the excellent performance of the films, a single-electrode triboelectric nanogenerator (HPP LM/PAN-TENG) pressure sensor was further developed. This sensor exhibited high sensitivity to pressure changes and accurately monitored both large and subtle human motions. More importantly, the sensor accurately captured the subtle features of early gait abnormalities with Parkinson’s disease, providing evidences for early diagnosis. The LM/PAN films are easy to prepare and can be produced at a large scale, with a broad application potential in fields of thermal management of electronic devices, electromagnetic protection, and wearable sensing.