Modeling and Application of Planar‐to‐3D Structures via Optically Programmed Frontal Photopolymerization

Abstract

Self‐folding of flat sheets into desired 3D structures gain great attention for fabrication of functional structures with complex geometries. Here, the authors present a photomechanical model to capture the bending and buckling behaviors for a recently developed fabrication method of frontal photopolymerization, which overcomes the limitations of high cost and tedious procedures existing among other approaches. This theoretical model consists of composite beam theory and NEP elastic function to comprehend the relationship between photopolymerization and mechanical deformation. Simulations of bending curvature with varying irradiation time and photo pattern are compared with experimental results to optimize the design space, and enable tunable and programmable planar‐to‐3D structures. Self‐folding structures such as flower, claw, soccer, pyramid, and saddle are fabricated by using the model as guidelines, indicating the potential applications in bionics, soft robotics, optics, and biomedicine. Shape‐morphing with the assistance of optically punched holes is also demonstrated to further improve the bending curvature.