Study On The Failure Mechanism During Ag-IPMC Movement

IPMC (Ion-exchange Polymer Metal Composite) is a new kind of intelligent polymer material. Its advantages include: light weight, fast response speeds, low energy consumption and large deformation. It has broad research and application prospects ranging from micro-bionic robots to advanced medical fields. It is also thought especially useful in intelligent low-noise underwater propulsion systems. Although IPMC exhibits superior performance to conventional actuators,its service life becomes a key limiting factor to its application. Therefore, this paper focused on determining the primary reasons for the failure of IPMC to move overtime.This thesis' covers three main objectives, firstly, after in-depth analysis of the movement mechanism on Ag-IPMC, the electric actuator model of Ag-IPMC samples was established and a test analysis system was created. Failure factors were identified by observing and recording the failure process. On the macro level, the basic factors leading to Ag-IPMC failure were determined by analyzing of the failure samples' surface characteristics,conductive efficiency and water loss characteristics.Secondly, an orthogonal experimental was designed to analyze the influence of three main factors (base film coarsening, solution concentration and temperature) in the Ag-IPMC preparation process on the properties of Ag-IPMC material. The experiment results showed that the three main factors significantly change the surface structure of Ag-IPMC material on the microcosmic level. The resulting changes affect the density and the surface quality of Ag-IPMC material coating, which notably enhance the longevity of the Ag-IPMC movement.Finally, active and inactive Ag-IPMC samples were characterized by using SEM and EDS experimental apparatus into surface topography, elemental composition and sample structure. The resulting data was then compared according to surface morphology,microstructure and chemical component. In addition, surface changes in an active sample after tensile strain test were compared with inactive sample surfaces to determine if any relationships with the surface crack formation. From analysis of the differences, the essential rationale for Ag-IPMC samples failure is that Ag changes into Ag2O under the action of electric current. This causes a dramatic increase in resistance, changes in the surface structure and plating peeling from the Nafion-117 surface. Consequently, these findings explain the reason for the Ag-IPMC materials failure mechanism.