| Ionic Polymer-Metal Composite(IPMC)is a type of electro-active polymer,which has many unique advantages including light weight,rapid response,large strain,great flexibility due to transfer mechanism of ion migration and special structure.And it has been extensively explored in the fields of electronic devices,biological medicine,aerospace and bionic robot.However,the existing research still lack knowledge of functional characteristics and influence mechanism of IPMC interface,which hinders the further development of IPMC.In view of the rough interface of IPMC,this paper conducts an in-depth study on interface modeling simulation and its influence mechanism on electromechanical properties.In this paper,according to the existing IPMC preparation process and adjusting the technological parameters,a set of orthogonal experiments were designed and 9 IPMC materials with different interface characteristics were prepared.The morphological features of IPMC materials were observed by SEM.The electrode thickness and interface area were obtained from SEM and the reasons for the interface generation were briefly analyzed.Laser displacement sensor and the Labview software were used to design experimental platform for testing the electric actuator performance of IPMC.Electrochemical workstation was used to test C-V curve of IPMCs to calculate its capacitance.The dividers method is adopted to calculate the fractal dimension of the interface.The geometrical models of existing research fail to show IPMC interface characteristics,so the W-M function is proposed to simulate the contour of the interface.Based on finite element,a method of fitting interface contour based on W-M function is established.In this paper,the internal mass transfer model of IPMC materials was described by Poisson equation and Nernst-Planck equation.The characteristic concentration is raised to reflect the deformation of the material.Interface established with actual profile,flat line,Koch curve of different generation and W-M curve were applied and compared in the mass transport modeling of IPMC.Compared to Actual interface,the error of the flat electrode model is large,that of all W-M function models is less than 4%,and the Koch curve model of different iterations is suitable to simulate the interface of specific fractal dimension.Based on the fitting result,this paper presents the empirical formula of the characteristic scale,which provides some guidance for the use of W-M function fitting interface.Based on the core parameters(fractal dimension and characteristic scale)of W-M function,the characteristic roughness is proposed to represent interface contour.The impact level of the fabrication process on the interface roughness is analyzed by the range analysis of orthogonal experiment and the result is that Sand-size>Cycles of IRP>Sandblast Pressure=Sandblast Time.In addition,the data analysis shows that capacitance and tip displacement of IPMC generally increase with the increase of interface characteristics roughness.In this paper,the research conclusion of IPMC rough interface provides some guidance to characterization,modeling and process improvement,and will promote the further application of the IPMC in engineering field. |
