#flexible #stretchable

The basic structure and function of a printed circuit board (PCB) has changed little in the last 50 years; individual integrated circuits and passive components are connected through copper traces, patterned from thin copper sheets laminated to a rigid fiberglass substrate. Advances such as flexible circuit boards, built on polyimide sheets, add some amount of flexibility, but these do not provide stretch or alter traditional 2D circuit topology. In contrast, there is an emerging set of applications that require stretchable, compliant electronics – including wearable devices, instrumented fabrics, and soft robots with distributed sensors and computation. Developing stretchable electronics faces two primary challenges: integration of active semiconductor devices in elastic substrates and providing stretchable, conductive interconnects. In this work, we combine 3D-printing of liquid metal materials with silicone rubber and PCB fabrication techniques to build solid 3D objects with active and passive electronic components distributed throughout. In this presentation, we will summarize our efforts in process development, material characterization, electrical modeling, and stretchable circuit fabrication demonstrating the potential of using liquid metal materials for realizing flexible and stretchable electronic systems. Long-term, we aim to enable wearable sensors and actuators, conformable electronic skins and textiles, and camera-free motion capture capabilities for soft robots and wearable human-machine interfaces.