Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botani...Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botanical tissues and animal muscles, we propose two sorts of fiber-dominated composite actuators. First, inspired by the deformation of awned seeds in response to humidity change, we fabricate passive fiber-dominated actuators using non-active aligned carbon fibers via 4D printing method. The effects of process parameters, structural parameters, and fiber angles on the deformation of the printed actuators are examined. The experimental results show that the orientation degree is enhanced, resulting in a better swelling effect as the printing speed increases. Then, motivated by the actuation mechanism of skeletal muscle, we prepare active fiber-dominated actuators using active polyurethane fibers via 4D printing and pre-stretching method. The effect of fiber angle and loading on the actuation mode is experimentally analyzed. The experimental results show that the rotation angle of the actuator gradually decreases with the angle from 45° to 60°. When the fiber angle is 0° and 90°, the driver basically stops rotating while shrinking along the loading direction. Based on the above actuation mechanisms, identical contraction behaviors are realized both in passive and active fiber-dominated soft actuators. This work provides a validation method for biologically actuation mechanisms via 4D printing technique and smart materials and adds further insights to the design of bioinspired soft actuators.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant 52005209,Grant 91948302,Grant 52021003,Grant No 52105295in part by the Natural Science Foundation of Jilin Province under Grant 20210101053JCThis work also supported in part by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003).
文摘Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botanical tissues and animal muscles, we propose two sorts of fiber-dominated composite actuators. First, inspired by the deformation of awned seeds in response to humidity change, we fabricate passive fiber-dominated actuators using non-active aligned carbon fibers via 4D printing method. The effects of process parameters, structural parameters, and fiber angles on the deformation of the printed actuators are examined. The experimental results show that the orientation degree is enhanced, resulting in a better swelling effect as the printing speed increases. Then, motivated by the actuation mechanism of skeletal muscle, we prepare active fiber-dominated actuators using active polyurethane fibers via 4D printing and pre-stretching method. The effect of fiber angle and loading on the actuation mode is experimentally analyzed. The experimental results show that the rotation angle of the actuator gradually decreases with the angle from 45° to 60°. When the fiber angle is 0° and 90°, the driver basically stops rotating while shrinking along the loading direction. Based on the above actuation mechanisms, identical contraction behaviors are realized both in passive and active fiber-dominated soft actuators. This work provides a validation method for biologically actuation mechanisms via 4D printing technique and smart materials and adds further insights to the design of bioinspired soft actuators.
