Self-Healing Liquid Metal Composite for Reconfigurable and Recyclable Soft Electronics

Soft electronics and robotics are in increasing demand for diverse applications. However, in contrast to rigid electronics, which are protected with stiff external supports and enclosures when deployed, soft electronics must maintain extreme compliance and cannot use these traditional means of protection, which can render them vulnerable and lead to premature disposal. This creates a need for soft and stretchable functional materials with resilient and regenerative properties to survive in unstructured environments. Here we show a liquid metal-elastomer-plasticizer composite for soft electronics with robust circuitry that is self-healing, reconfigurable, and ultimately recyclable. This is achieved through an embossing technique for on-demand formation of conductive liquid metal networks which can be reprocessed to rewire or completely recycle the soft electronic composite. Through this approach we achieve a combination of high electrical conductivity, high stretchability, and robust tolerance to damage. The embossing approach further enables soft, stretchable wiring to be created with resistance tunability over two orders of magnitude, while achieving conductivities as high as 45,400 S/cm at large strains. These skin-like electronics stretch to 1200% strain with minimal change in electrical resistance, sustain numerous damage events under load without losing electrical conductivity, and are recycled to generate new devices at the end of life. These soft composites with adaptive liquid metal microstructures can find broad use for soft electronics and robotics with improved lifetime and recyclability.