Digitally Programmable\nMicrophase Separation in Polymer\nNetwork Generates Microstructure Pattern

Polymers with microstructure patterns are crucial to\nmany applications,\nsuch as separation, optics, electronics, metamaterials, etc. However,\nintroducing microstructure patterns with diverse morphologies and\nfeature sizes ranging from nanometers to micrometers into large-area\npolymers remains a significant challenge. Here, we design a material\nsystem that enables digital programming microphase separation in a\npolymer network to generate microstructure patterns. The polymer network\nis engineered to allow digital programming of local modulus, which\narrests the length scale of microphase separation to generate various\nmicrostructures. These local modulus-regulated microstructures exhibit\neither bicontinuous or sea–island morphology and have various\nfeature sizes ranging from ∼100 nm to several micrometers.\nUsing household devices of an ink printer and an ultraviolet light\nlamp, the microstructure patterns can be programmed with fine resolutions\n(∼100 μm) over large areas (≫100 mm). The locally\nvaried microstructures have different capabilities to scatter light\nand result in a visible pattern. We further demonstrate this design\nwith a soft anticounterfeiting device. This approach of digital programming\nmicrophase separation in polymer networks is applicable to various\npolymers and provides a platform for designing many other functional\ndevices.