Cao Yanlin, Feng Xianke, Wang Shuang, Li Qi, Li Xiying, Li Hongyuan, Hong Wei, Duan Huiling, Lv Pengyu
State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China.
CAPT, HEDPS and IFSA Collaborative Innovation Center of MoE, Peking University, Beijing 100871, China.
Soft Matter. 2022 Nov 23;18(45):8633-8640. doi: 10.1039/d2sm01058e.
Soft actuators have a wide range of applications in medical instruments, soft robotics, 3D electronics, and deployable structures, where configuration transitions are crucial for their function realization. However, most soft actuators can only morph from the initial configuration directly to the final configuration under a single external stimulus. Herein, we report a novel soft actuator by 3D printing parallel strips with crescent cross-sections onto a thin PDMS film. Multiple configuration transitions are observed when the soft actuator swells in ethyl acetate. Four factors, , the geometric asymmetry of the strips, the fabrication-induced heterogeneity of the film, the differential swelling ratios of the strips and the film, and the geometric parameters of the actuator, are demonstrated to synergistically regulate the multiple configuration transitions of the actuator. Particularly, the underlying mechanisms for the configuration transitions are systematically investigated through experiments and theoretical analysis, and verified finite element simulation. Benefitting from the multiple configuration transitions, the grasp-release-re-grab function of the actuator is demonstrated under a single stimulus. This work contributes to fundamental understanding of the morphing behaviors and the novel design of soft actuators.
软致动器在医疗器械、软体机器人、3D电子和可展开结构等领域有广泛应用，其中构型转变对其功能实现至关重要。然而，大多数软致动器在单一外部刺激下只能从初始构型直接转变为最终构型。在此，我们报道了一种通过在薄PDMS膜上3D打印具有月牙形横截面的平行条带制成的新型软致动器。当软致动器在乙酸乙酯中膨胀时，会观察到多种构型转变。研究表明，条带的几何不对称性、薄膜制造引起的不均匀性、条带与薄膜的不同溶胀率以及致动器的几何参数这四个因素协同调节致动器的多种构型转变。特别是，通过实验和理论分析系统地研究了构型转变的潜在机制，并通过有限元模拟进行了验证。受益于多种构型转变，该致动器在单一刺激下展现出抓取 - 释放 - 再抓取功能。这项工作有助于对变形行为的基本理解以及软致动器的新颖设计。
