Near-infrared light-driven programmable shape memory polymer for self-shaping 3D printing methods

The development of 3D printing shape memory polymer (SMP) is restricted by the laborious manual programming for shaping, limited deformation modes, and the use of conventional heating methods for deformation. This study introduces a novel self-shaping 3D printing approach for SMPs that obviates the need for manual programming. The proposed method employs Fused Deposition Modeling (FDM) technology to embed built-in strain into planar print patterns. Near-infrared light is utilized to achieve non-contact, high-precision actuation, selective area heating, and accurate multi-step driving on thermally activated deformable structures. By selectively applying photothermal conversion agents to the sample surface and adjusting the printing paths, this approach enables multi-mode deformation of the self-shaping material. With optimized FDM printing parameters, the maximum shrinkage strain reaches 24.38% and the fastest response time is 0.25 s, allowing for flexible printing of self-shaping samples with varying deformation response speeds and modes. We further demonstrate various applications derived from this method, including biomimetic curling grippers, selectively deformable multi-angle biomimetic flowers, remotely controlled grasping and retrieval robots, morphing aircraft wings, and dancing robots. This self-shaping 3D printing method provides new insights into the design, fabrication, and application of complex functional structures in smart materials.