Design and Experiment of Soft Grasping Robot with Variable Stiffness Based on Jamming Principles of Layer and Particle

Aiming at the problems of poor load capacity and low stiffness of the soft grasping robot, combining the advantages of a pneumatic actuator and jamming principle, a variable stiffness soft finger combining layer jamming and particle jamming is designed. First of all, a multi-airbag soft actuator is proposed, which has the characteristics of bending inward and outward. Secondly, a hybrid variable stiffness structure is proposed, in which the granular material and the layer material are embedded in the same cavity, and the change of the shape of the two under the negative pressure improves the overall stiffness and load capacity. Thirdly, a stiffness theoretical model is established to analyze the factors that affect the variable stiffness and the stiffness change of the end of the flexible finger of the variable stiffness structure under different vacuum degrees. Finally, a prototype of the soft grasping robot is made to verify the variable stiffness performance and grabbing performance of the soft grasping robot. The test shows that the end stiffness of soft fingers increases by 6.25 times after vacuuming. When grabbing objects, the maximum load of a single finger is 4.96N, and the maximum load of a soft grasping robot is 12.47N, which can meet the requirements of general object grabbing.