Multistage Responsive Materials for Real‐time, Reversible, and Sustainable Light‐Writing

Abstract Stimulus‐responsive materials with designable integrated functions bridge the intelligent systems in future lifestyles with the Internet of Things (IoT). The growing trend for IoT and corresponding advanced devices will involve a great number of electronic disposables, which may place heavy burdens on the environment. Here, an elaborately designed multistage responsive material is reported for real‐time, reversible light‐writing based on organized stage‐by‐stage responsive behaviors and polarity‐dependent physicochemical fluorescence response, where the stimulus is accurately delivered through a completely reversible “light‐heat‐fluorescence” pathway. The resulted materials can be pollution‐freely written by hand‐controlled near‐infrared laser within 5 s, spontaneously erased within 20 s, and exhibit excellent re‐writing ability (more than 5000 times while the variance of chromaticity coordinates <0.0008), which is difficult to achieve by traditional laser writing technologies. This study is a step toward high‐performance long‐life functional devices based on reversible multistage responsive materials for future IoT lifestyles.