Design And Experimental Study Of An Electrostatic-Adhesive Soft Robotic Gripper

Rapid developments of soft robotics,materials science and stretchable electronics enable soft robotic grippers made of flexible or smart materials have the characteristics of high flexibility,complex environment adaptability and safe human-machine interaction compared to the traditional rigid grippers.However,limited by the structure of soft materials and the particularity of actuation methods,most soft grippers have problems such as insufficient gripping force,single grasping method and miscellaneous auxiliary equipment.Therefore,aiming at the deficiencies of current soft robotic grippers,this paper proposes an electroadhesive soft robotic gripper based on FinRay structure—FinEA gripper,to improve the grasping performance and the applied range of soft grippers.The main research contents are as follows:(1)Theoretical modeling and optimized analysis for electroadhesion.The basic mechanism of electroadhesion on dielectrics is analyzed.The static theoretical model of the coplanar bipolar electrode is established.The theoretical expression of electroadhesive force is quantitatively derived by Laplace equation.The optimal solutions of electrical parameters of the electroadhesive pad in a certain range are obtained by MATLAB,and the influences of each parameter on electroadhesive force are analyzed.(2)Studies on fabrication of electroadhevie pad and experiments of electroadhesive force.A flexible electroadhesive pad is fabricated by screen-printing.The electroadhesive force measurement platforms are built,and electroadhesive forces generated by the pads are quantitatively analyzed.The rationality for the design of measurement platform is verified via the comparison between the corresponding experimental data and theoretical analysis.Aiming at that the electroadhesive force generated by the pad will decrease significantly after several repeated use,experiments for verification are designed.The main reason for the decrease of the electroadhesive force after repeated use and the change laws of electroadhesive force are explored.And the methods to maintain or increase the adhesion stability were put forward.(3)Integrated design and experimental research of the electroadhesive soft robotic gripper.In order to achieve a self-adaptive surface fitting to the object and maximize the electroadhesion performance,a FinRay finger based on a fin-like structure is proposed.The influences of geometric parameters on the deformation performance of the FinRay finger are analyzed by ABAQUS/CAE.The FinRay finger is fabricated by molding using silicone rubber.A soft electroadhesive pad is fabricated.The static adhesion performances of the soft pads on the plane,convex and concave surfaces with different curvatures are quantitatively analyzed.The FinRay finger is combined with the soft electroadhesive pad,which results in a FinEA gripper.The qualitative and quantitative experimental studies on grasping performances of the FinEA gripper are carried out,which verifies the versality and reliability of the proposed FinEA gripper.