Bioinspired Ultra-Stretchable and Highly Sensitive Structural Color Electronic Skins

Organisms possess remarkably adaptive ability to complex environments. For example, chameleons can alter their skin color to adapt to varying environments, which has inspired significant advances in bioinspired soft electronic skins (E-skins), and their wide applications in wearable sensors, intelligent robots, and health monitoring. However, current bioinspired E-skins face challenges in ultra-stretchability, high sensitivity, and long-term stability owing to the intrinsic limitations associated with their mismatched interface between soft matrix and hard conductive fillers, hindering their practical applications. Here, it is reported that bioinspired structural color electronic skins (SC E-skins) that consist of liquid metal particles (LMPs), periodical ordered colloidal crystal arrays, and ultra-stretchable hydrogel, imparting synergistic and durable electrical-optical sensing capabilities. Such SC E-skins demonstrate outstanding performances including superior flexibility (elongation at break > 1100%), high sensitivity (gauge factor = 3.26), fast synergetic electric-optical response time (approximate to 100 ms), outstanding durability (over 1500 cycles), and high accuracy (R-2 > 99.5%). These bioinspired SC E-skins with excellent capability of converting mechanical signals into synergetic electrical-optical outputs hold great promise for smart wearable devices, affording a new horizon in developing advanced health monitoring technologies.