Research And Design Of Actuator Based On Dielectric Elastomer (DE)

For many emerging mechatronic applications,actuators commonly used motor reducers and pneumatic drives in traditional mechanical design,due to their complex structure,assembly and wear.They have been difficult to meet size-restricted areas such as miniaturization and robotics.Finding a suitable actuator has become a key issue.Dielectric Elastomer(DE)is a flexible smart material,which can produce large deformation at high voltage.Because it is a flexible polymer film material,it is convenient to design a suitable actuator according to the structural size and shape requirements.Compared with the driving technology of solenoid valve and cylinder,it have good flexibility,fast response,high energy conversion rate.So,it can be used as a more energy efficient,lighter,and lower cost actuator.However,the material has severe nonlinearity,and the deformation theory lacks systematic analysis.Therefore,in order to achieve the best performance of DE materials,the relationship between material geometry and performance must be determined.The main work done in this paper is as follows:(1)The electro-deformation force coupling model of DE material based on thermodynamic model is studied.The stress and strain curves of DE material under voltage and pre-tension load are analyzed by using Yeoh model and Gent model,which provides theoretical support for subsequent work.According to the simulation results,building the biaxial stretching platform.Design control system and the data acquisition module are used to determine the model parameters.The DC voltage loading experiment is performed,the causes of the actuator tear failure and electro-stability are analyzed,and the voltage threshold of the electrical breakdown is tested.Finally,the effect of alternating voltage on material properties is analyzed.(2)Deriving the mathematical model of the DE film cone actuator to derive the governing equation.The actuator production process and electrode selection were studied.The driving force and output displacement were measured by laser range finder and force sensor.The output performance of the cone actuator with different geometric parameters was analyzed.Through the above experimental and theoretical research,in view of the shortcomings of this actuator stroke and the nonlinear increase of output force during motion,this paper chooses the fully compliant bistable mechanism as the compensation mechanism of DE actuator.In order to match the actuator output performance,the geometric parameters of the fully compliant bistable mechanism are optimized to ensure a stable displacement output of the tapered actuator,and the dielectric high elastomer does not require continuous power supply to maintain its driving state.(3)Applying DE actuators to the field of bionic robots,designing and manufacturing bionic robot fish.The DE actuator is combined with a compliant bistable mechanism for the pectoral fin swing;the DE film is adhered to the PET sheet to make the pectoral fin fin,and the area of the pectoral fin in contact with the water is changed by controlling the voltage;the two sets of tapered actuators are Symmetrically arranged as a caudal fin,the fish tail is oscillated left and right to provide power by applying a voltage.The driving part of the bionic fish is entirely made of DE soft material,and the fish body is made by 3D printing technology,so it does not generate noise and has high energy utilization rate compared with the conventional underwater machinery.(4)The DE film is adhered to the flexible diamond structure to design the crawling robot,and a single friction mechanism is introduced to realize the telescopic crawling through the AC load.The actuator force-displacement relationship is analyzed by a nonlinear finite element and a pseudo rigid body model.The crawling robot was made using a photosensitive resin to carry out an experiment.