Hybrid Soft Actuator Driven by Temperature-Responsive Hydrogel and Soft Grid Skeleton with Residual Stress

We propose a hybrid soft actuator fabricated from a hydrogel and a soft grid skeleton to enable large deformation and control driving direction. In general, the hydrogel bilayer structure is difficult to integrate with a solid skeleton because hydrogel mainly composed of water has different mechanical properties from the solid skeleton. In this work, we fabricated a hybrid soft actuator by integrating a three-dimensional structure with temperature-responsive hydrogel. The concentration of the temperature-responsive hydrogel and the cross-linking agent were evaluated from the shrinkage ratio of the hydrogel working as a driving force. The soft grid skeleton was fabricated through multi-directional lithography of a photo-curable resin. From these results, the fabricated hybrid soft actuator showed bending deformation and repetitive response.