Progress and challenges in wearable electrochromic devices: a review

Electrochromic technology has made great progress and shown potential applications in various fields, such as green buildings, smart displays, and military camouflage. In recent years, wearable electrochromic devices (WECD) have received increasing attention for their smart and portable application prospects. Compared with conventional rigid devices, WECDs face more challenges in configuration and assembly. Therefore, this paper provides a comprehensive explanation of WECD, first introduces its core components, and then their flexible features. Then, the latest progress and advances in WECD construction are summarized in detail according to different structural forms. Some key properties of different structural forms are introduced and compared, and the advantages and disadvantages of each of their structures are presented. Finally, some of the present-day challenges and outlooks in WECD fabrication and operation are discussed to provide new insights for developing electrochromic devices for applications in smart wearable and flexible electronics.