Customizable single-layer hydrogel robot with programmable NIR-triggered responsiveness

Hydrogel robots are widely used in biomedical fields due to their excellent biocompatibility and response to external stimuli. However, traditional processing methods cannot rapidly fabricate complex structures, and smart response strategies often rely on double-layer structures fabricated from two materials with significantly different swelling properties. In this study, we present a single-layer hydrogel robot that can be fabricated in one step using a high-precision digital light processing (H-P DLP) 3D printing system. The robot has structural differences and the ability to maintain a repetitive response. Additionally, we fabricated several robot grippers to demonstrate their potential for customization and programming, as well as their potential applications in cargo delivery. Our work provides a new approach to achieve the formation and response of various irregular hydrogels, which is expected to advance the development of biomedical applications.