Seamless modulus gradient structures for highly resilient, stretchable system integration

Hybrid system integration of rigid components into stretchable systems is often necessary when targeting for valuable functions in various scenarios. Among them, (Young's) modulus gradient structures for system integration demonstrate excellent mechanical performance when stretched. However, the mechanical reliability is still limited under large deformation due to the inherent interface between materials of different modulus. Here, a seamless transition between heterogeneous moduli parts made with polydimethylsiloxane (PDMS)-based elastomers is presented for stretchable system integration by simply tuning their modulus via introducing a small amount of an additive into some parts of the substrate. These gradient structures not only provide a high stretchability (∼250%) for the overall system, but also improve the resilience of the system (can be stretched up to 50,000 cycles from 0 to 150% global strain) at the same time. The seamless modulus gradient structures provide a simple and effective way of allowing highly resilient and stretchable system integration for various soft intelligent systems.