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

Adv Mater. 2024 Apr 2:e2400082. doi: 10.1002/adma.202400082. Online ahead of print.

Abstract

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, it is reported 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 is further applied to fabricate skin-interfaced strain sensors and electromyogram sensors through 3D printing.

Keywords: asymmetric stretchable conductor; human interface; self‐assembly; self‐insulated; soft matter.