Modulus Engineered Substrate With Vertical Soft Interconnects for Ultra-Stable Stretchable Multilayer Electronic Systems

Stretchable multilayer electronic systems hold transformative potential for next-generation wearable electronics, soft robotics, and human-machine interfaces. However, the stretchability and stability are severely hindered by the interfacial mechanical and electrical mismatch of different components. Herein, by simultaneously combining modulus-engineered substrate with vertical soft interconnects, we report a multilayer electronic system design with both high stretchability and stability. The homologous soft-bridge and rigid-island design effectively reduces modulus mismatch and facilitates interfacial bonding, and the raw/hybrid liquid metal-based vertical interconnects efficiently alleviate Poisson effect thus ensuring stable mechanical and electrical connections. As a result, such engineered multilayer electronics demonstrate high stretchability (800% strain limit) and high stability (over 4000 cycles at 100% strain) that outperform the results from previously reported multilayered flexible electronic devices. A three-layer stretchable electronic system performs well as an electronic skin on a soft robot, and a wireless battery-integrated intelligent haptic system is also demonstrated.