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

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.