Bending‐Insensitive Intrinsically Flexible Ultraviolet Encoding Devices Based on Piezoelectric Nanogenerator‐Supplied Liquid Crystalline Polymer Fabrics

It is significantly challenging for state-of-the-art wearable electronics to stably monitor physicochemical signals under dynamic motions. Herein, a bending-insensitive, self-powered, and intrinsically flexible UV detector has been realized based on well-designed oriented composite fabrics, consisting of ionic liquid (IL)-containing liquid crystalline polymers (ILCPs) and piezoelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanogenerators. The novel composite fabrics establish effective UV illuminance-internal stress-electric signal conversion by coupling resistive and piezoelectric effects, with a fast response time of 190 ms. Particularly, benefiting from the intrinsic flexibility of composite fabrics, the ILCP/P(VDF-TrFE) device can maintain stable performance under dynamic bending even if the frequency is up to 2.5 Hz, with a bending insensitivity of less than 1% performance variation under 1.0 mW cm-2 UV light. Combined with the Internet of Things and the American Standard Code for Information Interchange (ASCII), wearable encoding electronics have been successfully implemented with a printing speed of 3.2 s per character under dynamic bending.