An Overstretch Strategy to Double the Designed Elastic Stretchability of Stretchable Electronics

Achieving or enhancing the elastic stretchability of inorganic stretchable electronics is critically significant. However, only two types of fundamental strategies-using the prestrained elastic substrate and designing the geometric layouts-are exploited thus far. This study proposes a third strategy, an overstretch strategy, applied beyond the designed elastic range of stretchable structures after transfer printing and bonding to a soft substrate. The theoretical, numerical, and experimental results collectively prove that the overstretch strategy can double the designed elastic stretchability of fabricated stretchable electronics and is valid for various geometrical interconnects with both thick and thin cross-sections. The underlying mechanism is that the elastic range of the critical part of the stretchable structure is doubled, owing to the evolution of the elastoplastic constitutive relation during overstretching. The overstretch strategy can be easily executed and combined with the other two strategies to enhance elastic stretchability, which has profound implications for the design, fabrication, and applications of inorganic stretchable electronics.