Research On Inchworm Bionic Soft Robot Based On Dielectric Elastomer

Unlike rigid robots and continuum robots,soft robots are developed and designed on the basis of smart soft materials.Among many smart soft materials,DE materials have outstanding advantages such as large deformation rate,high energy density and fast response.This article aims to design the inchworm-like bionic soft robot based on DE materials.According to the characteristics of DE material pre-stretching,DEMES formed by unequal pre-stretched DE material combined with flexible frame is used as the body of bionic inchworm,and the bionic pseudopod is designed according to the bionic principle,forming the inchworm-type bionic soft robot.The bionic soft robot has a small size(body length 30mm,width 58mm and height 30mm),the maximum speed can reach 5.5 body length/second,and has good flexibility and good passive adaptability.The main work completed in the paper is summarized as follows:(1)By deducing the constitutive relationship of DE materials and analyzing the prestretched characteristics of DE materials,it is found that the pre-stretched DE materials have the following advantages:the driving force and electro-induced deformation increase at the same voltage;the dielectric constant decreases and the stability increases.(2)According to the characteristics of the inchworm ? movement,the DEMES formed by the unequal axis pre-stretched DE material and the flexible frame is used as the body of the bionic inchworm,and the parameters affecting the output performance of the DEMES(a value,b value of the flexible frame,and the pre-stretched multiple of the DE material)are performed.After research,the optimal parameter parameters are obtained.Then the safe voltage range of DEMES is obtained through the static electrical breakdown experiment.Finally,the viscoelastic and hyperelastic models provided by ABAQUS software are used to simulate DEMES,and the results showed that the error between the simulation and experimental results is very small.(3)Soft robots usually deform back and forth under dynamic voltage,so the control variable method is used to study the effects of parameters of the dynamic voltage(frequency,peak,waveform,and AC/DC ratio)on the dynamic deformation of DEMES.Then through DEMES passive tensile experiment,a DEMES spring-damped dynamic model is established,and the model parameter values are fitted by the least square method.The comparison between the experimental and model results shows that the spring-damped dynamic model can better simulate the dynamic deformation of DEMES.(4)According to the bionic principle,a bionic foot is added to the DEMES to form an inchworm-inspired bionic soft robot,and the effects of the frequency,duty cycle of the square wave dynamic voltage and counterweight on the speed and turning performance of the soft robot are studied.The good flexibility and passive deformation ability of the soft robot are verified.Finally,the effects of the frequency,peak and duty cycle of the square wave voltage on the fatigue failure of the soft robot are studied.