Materials and Device Design for Epidermal UV Sensors with Real‐Time, Skin‐Color Specific, and Naked‐Eye Quasi‐Quantitative Monitoring Capabilities

Abstract Ultraviolet radiations (UVR) sensors provide quantitative and continuous measurement of UV‐induced dermal damage. The challenge though is to develop a sensor that simultaneously offers high sensitivity and rapid response to UVR, as well as compatibility to human skin and skin color specificity. In this paper, an epidermal UV sensor that uses new sets of material and device design strategies to deliver accurate UV intensity measurements is presented. The developed sensor provides real‐time and reversible detection performance (color change and recovery) in less than 30 s. By combining the UV photochromic and absorptive materials, a variety of personalized UV epidermal stickers can be developed to achieve naked‐eye quasi‐quantitative monitoring of UV exposure while simultaneously meeting the specific needs of different skin types. Experimental demonstrations validate the high applicability of these wearable UV sensors for managing the impact of UVR in the daily life.