Research Of Preparation And Reliability Of Particle-filled Conductive Silicone Rubber Films

With the development of electronic science and the increasing demands for electronic products,flexible wearable electronic products have received more and more attention due to their lightweight and portability.Conductive rubber film,with good electrical conductivity,elastic deformability and biocompatibility,will be widely used as flexible conductive material in the fields of electronics,communication and medical treatment.The preparation of conductive rubber film and its reliability were mainly studied in this project.The preparation of nickel coated aluminum powder by cyclic electroless nickel plating process was studied.The formulation of the conductive rubber film was determined and its preparation process was improved.The tensile fracture behavior and its influencing factors of conductive rubber films with different types of cracks were analyzed.The reliability of thin films under tensile fatigue and thermal oxidative aging was evaluated.Nickel-coated aluminum powder was prepared by cyclic electroless plating.The species and the loading amounts of conductive filler for conductive rubber film were determined,and the spraying process was optimized as well.The process of electrolytic ion transformation was detected by image colorimetry.Electroless nickel plating could be used to prepare nickel-coated aluminum powder for at least 8 cycles.The types and loading amounts of conductive filler did have an effect on the preparation of sprayed films.It was found that the comprehensive properties of the conductive rubber film by spraying had been close to the films by mould pressing method,in which the conductive rubber was filled with 200μm length carbon fiber.Moreover,the coating films exhibited an obvious tensile strain sensing characteristics.The prefabricated cracks impacted heavily on the tensile fracture behavior of conductive rubber films.The conductive rubber films with different prefabricated cracks were uniaxially stretched.It was found that the crack length,the crack shape and the angle of the crack with the stress had a great influence on the properties of the films.The initiate position of the crack was linked to the angles between the prefabricated crack tips and the tensile stress.The secondary cracks as well as the carbon fibers had hindered the crack propagation in the films.Conductive stability of the conductive rubber films was excellent.The changed electrical conductivity of films was within one order of magnitude after 10~5 cycles of cyclic stretching.The aging time 24h,is the key point of the electrical properties and mechanical properties of the films.The performance changing trend of the films is rapidly first and then slowly with time,whereas the changed electrical properties of the films were still less than one order of magnitude in the aging time of 240h.It could be concluded that the carbon fiber filled conductive rubber film exhibits high reliability in thermal oxidative enviroment.