Green wearable electronics are attracting increasing attention to eliminate harmful byproducts generated by traditional devices. Although various degradable materials have been explored for green wearable electronics, the development of degradable elastomers with integrated characteristics of low modulus, self-adhesion, high resilient, and low hysteresis remains challenging. In this work, a degradable elastomer poly(1,8-octanediol-co-citrate-co-caprolactone) (POCL) is reported, in which a loosely cross-linked network contains plenty of entangled flexible chains. The coexistence of covalent cross-links and entanglements of long polymer chains endows the elastomer with good resilience and low hysteresis, in addition to low modulus and self-adhesion. Taking advantage of the unique mechanical properties, epidermal strain sensors based on the POCL elastomer were prepared, which exhibited good adhesion to human skin, high sensitivity, high response rate, and excellent fatigue resistance. We also fabricated stretchable electroluminescent devices using this degradable elastomer and demonstrated the recyclability of the nondegradable materials in the electronic device.
Keywords: degradable elastomers; epidermal electronics; green wearable electronics; low hysteresis; robust elasticity.