The Design And Performance Of Pneumatic Soft Actuators Based On Elastomer Materials

As an emerging research field,soft robot has attracted more and more researchers' attention in recent years.Because it is made of soft materials,the soft robot has super flexibility and has a higher degree of freedom and environmental adaptability compared with traditional rigid robots.Soft actuators are mainly made of compliant materials and are an important part of soft robots.They are basically used as the power components of soft robots.In view of the current research on soft actuators and some defects that still exist in soft actuators,this paper proposes to use the manufactured soft tubes to assemble two different types of soft actuators,including soft bending and torsional actuators.The relevant parameters that affect the actuation performance of the two actuators are systematically studied.The research results provide a theoretical basis and some reference significance for further exploration on the structural design of soft actuators.First of all,the 30 and 50 models in the Ecoflex series of silicone rubber were preliminarily selected as the main materials for making soft actuators.The design scheme and specific production steps of soft tubes were given.Two different design solutions were proposed for two different soft actuators and comparative analysis was conducted from multiple angles to select the best structural design solution.The specific manufacturing method of each actuator is given later and the actuation principle is explained by combining the three-dimensional model of the soft actuator.Secondly,we establish a constitutive model according to the designed soft actuators.Uniaxial tensile samples were made from the selected materials with a mold and subjected to uniaxial tensile experiments using equipment to obtain stress-strain curves of the two soft materials.The preliminary conclusion that Ecoflex-30's large deformation ability is better than Ecoflex-50 is obtained by comparison.Then a mathematical model of bending kinematics is established for the designed soft bending actuator and a mathematical model of torsional kinematics is established for the designed soft torsional actuator according to the principle of virtual work.Obtaining the general relationship between the relevant structural parameters and the actuation performance of the soft actuator,and providing theoretical guidance for the structural design of the soft actuator.Then we use ABAQUS software as the simulation platform to simulate the twosoft actuators.Importing the tensile data obtained from the uniaxial tensile experiment into ABAQUS finite element simulation software to perform the constitutive model fitting of the material,and finally obtain the fitting parameters of the relevant models.Using PROE to create 3D models of soft actuators with different structural parameters and these 3D models were sequentially imported into ABAQUS for simulation experiments.By discussing the relevant parameters that may affect the actuation performance of the actuator and combining the results of simulation experiments,the best materials,the best structural design parameters and the structural shape of the inner cavity of the soft tube suitable for the production of the soft actuators are preliminarily determined.Finally,we use the purchased devices to build an experimental test platform for soft actuators;Through the introduction of the preparation method of soft actuators,physical samples of soft actuators with different structural sizes are manufactured.Using the experimental test platform to test the actuation performance of the physical samples of the soft actuator and statistically analyzing the relevant experimental data.By analyzing the experimental data of the influence of the relevant parameters on the actuator actuation effect,combined with the results of the simulation experimental data,the structural dimensions of the two actuators are finally determined.Ecoflex-30 is the best soft material for making two kinds of actuators.The best inner cavity structure of silicone tube is circular structure and the inner cavity radius is 2.0 mm.The length of the bending actuator is determined to be 80 mm and the optimal pitch of the torsional actuator is 24 mm.The research has great application potential in the fields of production lines and medical.