Research And Application Of Dielectric Elastomer Driving Unit

Dielectric elastomer(DE)is a typical representative of EAP.When the material is affected by electric field,it can expand in the plane direction,and has reversible deformation.When the external electric field is removed,the material gradually returns to its original state.Rapid response,large deformation,light weight and low price make it a hot research topic in recent years.It has a very broad prospect in bionic robot,sensor,biomedicine,and has become a highly concerned subject in foreword disciplines such as flexible machinery and soft matter scienceIn this paper,based on the principle of electromechanical coupling of de actuator,a numerical analysis model of DE thin film under different stretching modes is established.Based on the deformation characteristics of DE thin film,a coiling cylindrical driving unit is designed and manufactured.The deformation characteristics of the driving unit are studied by theoretical modeling,finite element simulation and experiment,and the optimized parameters of the driving unit are obtained It is used in the manufacture of mechanical grab.The main work and research results are as follows(1)the numerical analysis model of the electric deformation of acrylate film driving material is established,and the electric deformation effect of the film under different stretching modes is analyzed.The theoretical analysis shows that the electric deformation effect of the film is the best under the equal biaxial pre stretching mode,and that the higher the pre stretching multiple is,the better the voltage is when λ=4 According to the empirical formula,numerical analysis and test data,the safe working area of the film is obtained.It is found that the dielectric strength failure plays an important role in several failure modes.(2)a tensile device which can realize uniaxial and biaxial tension is designed and manufactured.At the same time,the test-bed of the area of the electric deformation is built.The manufacturing process of the film sample and the influence of the distance between the edge of the wire and the electrode and the frame are discussed.The conclusion that the direct placement of the lead-out wire and more than twice the width of the electrode have little influence on the area change is obtained.At the same time,the experiment and theory are compared The results show that the theoretical analysis is in good agreement with the experimental results under the condition of small pretension rate.With the increase of pretension rate,the error increases,but the overall trend is the same.Under the condition of λ=4,the deformation effect is the best.Under the condition of 4KV voltage,110%of the plane product strain can be produced.(3)based on the deformation characteristics of the thin film,the cylindrical driving unit is designed and manufactured,and the manufacturing process of the driving unit is discussed.Based on the thin film theory,the mathematical models of the linear and curved driving units are established.The electric deformation of the thin film and the driving units are simulated and analyzed by the COMSOL finite element software.(4)the deformation performance of the driving unit is characterized by the axial displacement,axial force and bending angle.The influence of the number of coils,spring parameters and pretension rate on the performance of the driving unit is compared.The optimized parameters of the driving unit are obtained.Based on the optimized parameters,the mechanical grab is made and the grab performance is tested.