Zhang Zheng, Ni Xiangqi, Wu Helong, Sun Min, Bao Guanjun, Wu Huaping, Jiang Shaofei
College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, China.
Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education and Zhejiang Province, Zhejiang University of Technology, Hangzhou, China.
Soft Robot. 2022 Feb;9(1):57-71. doi: 10.1089/soro.2019.0195. Epub 2021 Jan 8.
This study presents the design and test of a novel self-adaptive soft gripper, integrating pneumatic actuators and bistable carbon-fiber reinforced polymer laminates. The morphology was designed using the distinct structural characteristics of bistable structures; and the stable gripping configuration of the gripper was maintained through the bistability without continuous pressure application. The sufficient compliance of bistable structures makes the gripper versatile and adaptable to gripping deformable objects. First, a pneumatic-actuated method was introduced to achieve the reversible shape transition of the bistable structure. Next, three arrangement methods for actuators were analyzed with respect to the bistable transition and curvature, where it was found that the cross-arrangement is optimal. The effects of pneumatic actuators with different geometrical parameters on the response times are discussed, and the results show that the bistable structure can achieve shape transition within milliseconds under low pressure. Furthermore, the numerical and experimental results show good agreement between critical pressures and out-of-plane deformation. Furthermore, the shape retention function of the soft gripper was studied by using it to grasp objects of various sizes even when the pressure was reduced to the initial state. The bistable laminates exhibit sufficient compliance, and the deformed laminates can automatically accommodate the deformation of objects. The relationship between the weight and size of available gripping objects was studied; functional tests confirmed that the proposed soft gripper is versatile and adaptable for gripping objects of various shapes, sizes, and weights. This gripper has immense potential to reduce energy consumption in vacuum environments such as underwater and space.
本研究展示了一种新型自适应软夹爪的设计与测试，该夹爪集成了气动执行器和双稳态碳纤维增强聚合物层压板。利用双稳态结构独特的结构特征设计其形态；通过双稳态在不持续施加压力的情况下保持夹爪的稳定抓取构型。双稳态结构足够的柔顺性使夹爪具有通用性，能够适应抓取可变形物体。首先，引入一种气动驱动方法来实现双稳态结构的可逆形状转变。接下来，针对双稳态转变和曲率分析了执行器的三种布置方法，发现交叉布置是最优的。讨论了具有不同几何参数的气动执行器对响应时间的影响，结果表明双稳态结构在低压下能在毫秒内实现形状转变。此外，数值和实验结果表明临界压力和平面外变形之间具有良好的一致性。此外，通过使用软夹爪抓取各种尺寸的物体来研究其形状保持功能，即使压力降至初始状态时也是如此。双稳态层压板表现出足够的柔顺性，变形后的层压板能够自动适应物体的变形。研究了可用抓取物体的重量与尺寸之间的关系；功能测试证实，所提出的软夹爪具有通用性，适用于抓取各种形状、尺寸和重量的物体。这种夹爪在水下和太空等真空环境中具有巨大的降低能耗的潜力。
