Stretchable, Transparent, Tough, Ultrathin, and Self-limiting Skin-like Substrate for Stretchable Electronics

摘要

Human skin is highly stretchable at low strain but becomes self-limiting when deformed at large strain due to stiffening caused by alignment of a network of stiff collagen nanofibers inside the tissue beneath the epidermis. To imitate this mechanical behavior and the sensory function of human skin, we fabricated a skin-like substrate with highly stretchable, transparent, tough, ultrathin, mechanosensory, and self-limiting properties by incorporating piezoelectric crystalline poly((vinylidene fluoride)-co-trifluoroethylene) (P(VDF-TrFE)) nanofibers with a high modulus into the low modulus matrix of elastomeric poly(dimethylsiloxane). Randomly distributed P(VDF-TrFE) nanofibers in the elastomer matrix conferred a self-limiting property to the skin-like substrate so that it can easily stretch at low strain but swiftly counteract rupturing in response to stretching. The stretchability, toughness, and Young's modulus of the ultrathin (similar to 62 mu m) skin-like substrate with high optical transparency could be tuned by controlling the loading of nanofibers. Moreover, the ultrathin skin-like substrate with a stretchable temperature sensor fabricated on it demonstrated the ability to accommodate bodily motion-induced strain in the sensor while maintaining its mechanosensory and thermosensory functionalities.