2023/12/13 by Soo Young Cho, Dong Hae Ho, Sae Byeok Jo +1 · 1 voice · 3 citations
Engineering · Materials Science · Physics and Astronomy · #Advanced Materials and Mechanics #Micro and Nano Robotics #Pickering emulsions and particle stabilization
paper · pdf · doi:10.1088/2631-7990/ad1574
openalex publication_date 2023/12/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/14
Abstract Recent advances in functionally graded additive manufacturing (FGAM) technology have enabled the seamless hybridization of multiple functionalities in a single structure. Soft robotics can become one of the largest beneficiaries of these advances, through the design of a facile four-dimensional (4D) FGAM process that can grant an intelligent stimuli-responsive mechanical functionality to the printed objects. Herein, we present a simple binder jetting approach for the 4D printing of functionally graded porous multi-materials (FGMM) by introducing rationally designed graded multiphase feeder beds. Compositionally graded cross-linking agents gradually form stable porous network structures within aqueous polymer particles, enabling programmable hygroscopic deformation without complex mechanical designs. Furthermore, a systematic bed design incorporating additional functional agents enables a multi-stimuli-responsive and untethered soft robot with stark stimulus selectivity. The biodegradability of the proposed 4D-printed soft robot further ensures the sustainability of our approach, with immediate degradation rates of 96.6% within 72 h. The proposed 4D printing concept for FGMMs can create new opportunities for intelligent and sustainable additive manufacturing in soft robotics.