Bioinspired Omnidirectional Interface Engineered Flexible Island for Highly Stretchable Electronics.

With the advancement of electronics, there is a growing need to effectively combine rigid, flexible, and stretchable materials to build hybrid electronics. However, the interfacial transition between rigid/flexible and stretchable substrates presents considerable challenges, mainly due to differences in elastic moduli, complicating their integration for practical usage. Here, bioinspired omnidirectional interfacial-engineered flexible islands (BOIEFI) are introduced for a robust transition from flexible to stretchable substrates. These BOIEFIs enable the creation of highly stretchable and durable hybrid substrates capable of withstanding diverse physical deformations such as stretching, twisting, and even poking. Inspired by plant roots, BOIEFIs are designed with primary and secondary root structures that provide flexible mechanical interlocking between substrates with different elastic moduli. Through experimental and computational methods, optimized BOIEFIs exhibit significantly enhanced stretchability and improved fatigue life. To demonstrate the broad applicability, light-emitting diodes (LEDs) are integrated into BOIEFIs to establish a stretchable display. In addition, a human-machine interface device with soft pressure sensors and an LED array is fabricated for the implementation of hybrid electronics. This approach facilitates the harmonious integration of rigid, flexible, and stretchable substrates, leading to the creation of soft, highly stretchable, and durable hybrid electronics.