Li Mingge, Huang Xiaoming, Liu Quan, Yin Zhongjun
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China.
Soft Robot. 2025 Feb;12(1):56-67. doi: 10.1089/soro.2023.0241. Epub 2024 Jul 26.
As the chameleon tongue swallows the food, it wraps the entrapped meat around the food, ensuring that it is completely enclosed and preventing it from falling off. Inspired by swallow behavior, this article introduces the design, manufacture, modeling, and experimentation of a variable stiffness swallowing gripper (VSSG). The VSSG is comprised of an intimal membrane, an adventitial membrane, and an internal medium of particles and liquid water. This gripper integrates swallowing behavior with a particle jamming mechanism, exhibiting both soft and rigid state. In the soft state, it gently swallows objects by folding its intimal and adventitial membranes. In the rigid state, the bearing capacity is enhanced by promoting particle jamming phenomenon through pumping out liquid water. Therefore, the proposed gripper has the capability to mitigate the issue of extrusion force applied on the object, while simultaneously enhancing the load-bearing capacity of swallowing gripper. In this article, the swallowing principle of the VSSG is analyzed, the mathematical model of the holding force and extrusion force is deduced, and preliminary experiments are carried out to verify the actual gripping effect of the gripper. The experimental results demonstrate that the VSSG can successfully swallow objects of different shapes in the soft state, exhibiting excellent flexibility and adaptability. The carrying capacity of the gripper in the rigid state increased approximately twofold compared with its soft state. In addition, several swallowing grippers with different filling medium were comparatively studied, and the results show that the VSSG has a large load-bearing capability.
当变色龙的舌头吞食食物时，它会将困住的猎物缠绕在食物周围，确保其完全被包裹起来，防止猎物掉落。受吞咽行为的启发，本文介绍了一种可变刚度吞咽式夹爪（VSSG）的设计、制造、建模和实验。VSSG由内膜、外膜以及颗粒和液态水组成的内部介质构成。这种夹爪将吞咽行为与颗粒堵塞机制相结合，呈现出柔软和刚性两种状态。在柔软状态下，它通过折叠内膜和外膜来轻柔地吞咽物体。在刚性状态下，通过抽出液态水促进颗粒堵塞现象，从而提高承载能力。因此，所提出的夹爪有能力减轻施加在物体上的挤压力问题，同时提高吞咽式夹爪的承载能力。本文分析了VSSG的吞咽原理，推导了夹持力和挤压力的数学模型，并进行了初步实验以验证夹爪的实际夹持效果。实验结果表明，VSSG在柔软状态下能够成功吞咽不同形状的物体，展现出出色的灵活性和适应性。夹爪在刚性状态下的承载能力与其柔软状态相比增加了约两倍。此外，对几种填充不同介质的吞咽式夹爪进行了对比研究，结果表明VSSG具有较大的承载能力。
