High heat storing and thermally diffusive artificial skin for wearable thermal management

Abstract

Thermal management for wearable devices is of great importance since heat generation from electronic devices can cause adverse effects such as skin burns and malfunctioning of the devices. Here, we present an advanced thermal skin (ATS) based on a hybrid structure that exhibits both high thermal diffusivity and thermal storage capability. Silver flake/polydimethylsiloxane (PDMS) serpentine structure (SPS) and sodium-acetate-based hydrogel matrix (SAHM) form an interfacial layer between the skin and wearable device not only to thermally protect the skin but also to prevent the device from malfunctioning by absorbing the heat released from the device. The high thermal diffusivity of SPS serves to spread the heat, while the high thermal storage capability of SAHM facilitates heat absorption without a significant temperature increase. Unlike the general phase change materials (PCMs), SAHM retains a small modulus change of 4.8 fold while maintaining comparable heat capacity to paraffin. Such a skin-like softness of ATS regardless of its phase has not yet been reported elsewhere to the authors’ best knowledge. This property enables conformal contact with the deformable surface and increases its applicability to wearable thermal management, and in this regard, we expect that this study will make significant contributions to the heat management of future wearables.