Self-Healing Soft Printed Circuits and Bioelectronics with Liquid Metal

Soft polymers blended with liquid metal (LM) exhibit unique combinations of high electrical conductivity, high stretchability, and low elastic stiffness. They can be utilized as conductive inks for stretchable printed circuits or as intrinsically soft bioelectronic interfaces for physiological sensing. Depending on the choice of polymer matrix material, these composites can be engineered to be self-healing – i.e. capable of sponstaneously restoring their material and electrical connectivity after being mechanically damaged or severed. In this talk, I will review recent contributions from my research group in creating soft, stretchable, and self-healing conductive materials using LM-embedded polymer composites. This will include printable conductive inks composed of “bi-phasic” combinations of eutectic gallium-indium (EGaIn) with nanomaterials like MXenes, graphene oxide, or Ag flakes. I will also discuss recent efforts to create self-healing and electrically reprogrammable conductive materials using ionogels and organogels as the polymer matrix material. For all of these material systems, I will highlight their potential application for a variety of use cases in healthcare, wearable computing, and soft robotics. These range from bioelectronic interfaces for neuromuscular stimulation to soft sensors and circuitry for a variety of bio-inspired soft robotic implementations.