Patterning, morphing, and coding of gel composites by direct ink writing

Abstract

Many creatures gain unique patterns on their bodies, which not only represent their distinct characteristics but also endow diverse functionalities that are crucial to their survival. Though being common in nature, realizing diverse patterns with a number of functionalities and well-defined hierarchical structures in biomimetic materials remains challenging. Here, relying on the fast and quantitative reaction between poly(penta fluorophenyl) acrylate gel and alkylamine derivatives, an efficient method named direct ink writing (DIW) for constructing versatile functional patterns on gels is developed by using alkylamines as the ink and a capillary as the pen. Through carefully designing alkylamine derived functional groups, a variety of functional patterns are programmed on the gel. Precisely tuning the ink concentration, volume, and reaction time results in desired bending angles, curvatures and targeted shape morphing. Further, by virtue of programmable shape morphing, and the dynamic multi-responsive fluorescent ink together with a “POOLING” data extraction algorithm used in Convolutional Neural Network, advanced data encryption and anti-counterfeiting are achieved. This work not only provides a robust tool for constructing functional patterns on biomimetic materials, but also inspires new approaches for data encryption and protection, and builds a connection between smart gels and artificial intelligence.