Robotics systems, wearable electronics and other fields have benefited from recent advancements in soft electronics, but materials developed to date lack the protective qualities of rigid electronics. A flexible yet self-healing composite has been formulated at Virginia Polytechnic Institute and State University (Virginia Tech) to fill this gap.
The soft, skin-like circuits can withstand numerous damage events under load without losing electrical conductivity and can be recycled to generate new circuits at the end of a product’s life. The rubbery styrene-isoprene-styrene copolymer, inside of which are suspended tiny droplets of liquid metal also represents a self-healing, reconfigurable material for diverse applications.
The liquid metal droplets are initially dispersed in the elastomer as electrically insulated, discrete drops. An embossing method is applied to selectively connect droplets and develop tunable circuits, forming a liquid metal-elastomer composite that functions even under extreme damage. If a hole is punched in these circuits, the metal droplets make new connections to continue the transfer of electric power.
The circuits described in Communications Materials will also stretch without losing their electrical connection, as demonstrated by the ability to pull the stretchable electronics to over 10 times its original length without failure.
