Self‐Powered Fast Response Flexible Ultraviolet Sensors Based on Reversible Deformed Nanowires for UV Communications Under Sunlight

ABSTRACT For flexible UV sensors, realizing fast photoelectric response and dynamic sensing with low energy consumption is a trend for future advanced industries. Here, we present a method for the preparation of intrinsically flexible, fast‐responding, and self‐powered all‐polymer‐based UV photoelectric sensor with potential applications in UV communication and smart sensing. The sensor is fabricated by co‐electrospinning photo‐responsive reversibly deformable azobenzene‐containing polymer nanowires (DNC) with piezoelectric poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) to form composite fiber fabrics, followed by ionic liquid (IL) incorporation to obtain the DNC/P(VDF‐TrFE)/IL sensing film. Among them, DNC serves as the UV‐responsive unit, exhibiting excellent solvent stability and achieving reversible expansion up to 20% in diameter under UV irradiation. The nanowires are aligned along the fiber orientation direction, enabling efficient stress transfer along the fibers. Combined with the piezoelectric properties of P[VDF‐TrFE], the device achieves the conversion from UV illumination to internal stress and subsequently to electrical signals, endowing it with exceptional UV response characteristics. The device has a response time of only 50 ms under UV light, accurate conversion of photoelectric signals in the range of 5–101 mW·cm −2 , and stable performance after 5000 cycles. It is also capable of a dynamic bending response. As a proof of concept, we successfully integrated the sensor into a Bluetooth‐enabled wireless UV monitoring system, showcasing its dual functionality for both UV communication and smart sensing under daily light conditions.