Recent advances and a roadmap to wearable UV sensor technologies

The tremendous impact of UV radiation on every individual has resulted in massive interest in development of new sensor technologies to effectively monitor the solar exposure. However, there is no comprehensive review that critically discusses the advances made in the field of wearable UV sensor technologies and to position them as next-generation mass-deployable wearable devices. Herein, this gap is addressed by first classifying UV detection technologies into photoelectric and photochromic systems and summarizing their unique strengths and drawbacks. This is followed by a discussion on the integration of novel materials and design concepts with these technologies to develop wearable UV sensors. Then, the commercially available wearable UV sensors are examined thoroughly together with their limitations. Toward the end, a highly critical future outlook is provided, wherein the role of technological and regulatory interventions in assisting the development and integration of wearable UV sensors in the day-to-day activities is discussed. More importantly, the purpose of this review is not only to provide an in-depth understanding of the underlying UV detection mechanism, design principles, and wearable technologies but also to act as a roadmap for those interested in the development and regulation of commercially deployable wearable UV sensors.