Self-Assembly Enabled Printable Asymmetric Self-Insulated Stretchable Conductor for Human Interface.

Soft and stretchable conductors with high electrical conductivity and tissue-like mechanical properties are crucial for both on-skin and implantable electronic devices. Liquid metal-based conductors hold great promise due to their metallic conductivity and minimal stiffness. However, the surface oxidation of liquid metal particles in polymeric matrices poses a challenge in forming a continuous pathway for highly conductive elastic composites. Here, we report a printable composite material based on liquid metal and conducting polymer that undergoes a self-assembly process, achieving high conductivity (2089 S cm -1 ) in the bottom surface while maintaining an insulated top surface, high stretchability (>800%), and a modulus akin to human skin tissue. This material was further applied to fabricate skin-interfaced strain sensors and electromyogram (EMG) sensors through 3D printing. This article is protected by copyright. All rights reserved.