A study on the current density distribution in the circular contact surface

The distribution of the current density in the circular contact surface between two conducting semi-infinite bodies is theoretically analyzed. The current flow characteristics in the contact surface are simulated by solving a set of simultaneous equations derived from an analogy to the electrostatic charge distribution problem. The current density distribution is measured for uniform size of microcontacts by using enamel-coated copper wires and electrolyte, and the experimental results are compared with the calculated current density for various densities of the microcontact. It is revealed that the experimental and theoretical results are in good agreement. By using the proposed theoretical model the current density can be calculated also for circular contacts with arbitrary size and distribution of microcontacts, if the size and distribution of microcontacts are given from experimental or theoretical studies. Therefore, the proposed model can be used effectively to determine the current density distribution in the circular-shaped contact surface with multiple microcontacts