Customizable Single-Layer Programmable Deformation Hydrogel Robots Based on One-Time Fabricating with Near-Infrared-Triggered Responsiveness.

Programmable deformation hydrogel robots have garnered significant attention in biomedical fields due to their ability to undergo large-scale reversible deformation. As clinical demand rises, there is a need for hydrogel robots that are easy to process and operate, and can undergo programmable deformation. Here, we propose a method to fabricate single-layer programmable deformation hydrogel robots in one step using a high-precision digital light processing 3D printing system. Two kinds of deformable elements with different structure distribution on the top and bottom sides are produced by using two kinds of focused light with varying intensities. By combining these deformable elements, we create four basic modules with different and fixed deformable shapes. The desired shape deformation in hydrogel robots can be achieved by programming the combination of these four basic modules. The hydrogel robots exhibit reversible repeat deformation under near-infrared light stimulation. We validate our approach by fabricating several scaffolds using combinations of the four basic modules, demonstrating the feasibility of programming deformation and the potential application of these scaffolds in pipeline movement. This research provides the feasibility for the simple programming deformation of hydrogel robots and offers a novel approach for fabricating programmable deformation hydrogel robots in biomedical fields.