▎ 摘　　要

A small number of authors have focused on the theoretical investigation of electrical conductivity for polymer/graphene systems, in spite of more experiment studies in this field. Here, a model is developed and evaluated for conductivity of graphene system based on the roles of tunneling mechanism and interphase pieces. Also, an equation is expressed for tunneling size assuming the interphase pieces. The productions of new model are connected to the experimented numbers of some nanocomposites. In addition, the tunneling size is calculated at unalike filler amounts for the examples. The stimuli of different factors on the tunneling size and nanocomposite's conductivity are also studied using the developed equations. The outputs of new model show respectable matching with the experimented values. The dimensions of graphene and interphase layer significantly affect the tunneling size and nanocomposite's conductivity. The developed equations reasonably predict that small tunneling size and high conductivity are obtained by high graphene amount, thin and large nanosheets besides a thick interphase. Thinner nanosheets (t < 2 nm) produce the tunneling size of about 0, while t = 5 nm and graphene diameter (D) of 0.5 mu m increase the tunneling size to 18 nm. Also, t = 1 nm and D > 1 mu m produce the conductivity of 0.9 S/m, while t > 4.5 nm and D < 1 mu m cause an insulated sample. The contributions of all factors to the tunneling size and conductivity are discussed. The developed model is beneficial to enhance the performance of breast cancer biosensors, since the electrical conductivity plays a main role in the efficiency of biosensors.