High-Stretchable and Thermally Conductive Elastomeric Composites for Heat Dissipation in Flexible Electronics

Abstract

The diversification of wearable devices and flexible electronics has spurred an increasing demand for elastomeric composites that exhibit both high thermal conductivity and excellent tensile performance. Typically, materials with high thermal conductivity have high Young’s moduli, which are not ideally suited for flexible electronics. This study introduces a straightforward design strategy to develop a soft (with a fracture elongation of 372% and a low Young’s modulus of 463 kPa) and thermally conductive (2.21 W/(m·K)) composite made from liquid metal and hydroxyl-terminated polydimethylsiloxane elastomer. By adjusting the ratio of hydroxyl-terminated polydimethylsiloxane, this method controls the polymer network and leverages a unique solid–liquid coupling mechanism that allows the liquid metal to deform in tandem with the silicone matrix. The presence of uniformly distributed liquid metal droplets not only enhances the mechanical properties of the matrix but also boosts the heat dissipation capacity of the elastomer composite. Furthermore, this material demonstrates remarkable thermal stability and reliability, maintaining its integrity through multiple thermal shock cycles. This research underscores the vast potential of these materials for thermal management in next-generation flexible electronic devices and wearables.