Digitally Programmable Microphase Separation in Polymer Network Generates Microstructure Pattern.

Polymers with microstructure patterns are crucial to many applications, such as separation, optics, electronics, metamaterials, etc. However, introducing microstructure patterns with diverse morphologies and feature sizes ranging from nanometers to micrometers into large-area polymers remains a significant challenge. Here, we design a material system that enables digital programming microphase separation in a polymer network to generate microstructure patterns. The polymer network is engineered to allow digital programming of local modulus, which arrests the length scale of microphase separation to generate various microstructures. These local modulus-regulated microstructures exhibit either bicontinuous or sea-island morphology and have various feature sizes ranging from similar to 100 nm to several micrometers. Using household devices of an ink printer and an ultraviolet light lamp, the microstructure patterns can be programmed with fine resolutions (similar to 100 mu m) over large areas (>> 100 mm). The locally varied microstructures have different capabilities to scatter light and result in a visible pattern. We further demonstrate this design with a soft anticounterfeiting device. This approach of digital programming microphase separation in polymer networks is applicable to various polymers and provides a platform for designing many other functional devices.