Reducing Contact Resistance Using Compliant Nickel Nanowire Arrays

Electrical contact resistance can be reduced using an array of compliant and conductive nanowires which make a large area of intimate contact with an opposing surface. In this paper, analyses of electrical contact resistance, fabrication methods, and experimental results of contact resistance for compliant nickel nanowires are presented. To analyze, predict, and measure the contact resistance, models of surface contact between an array of conductive nanowires and a spherical tip probe are presented. Then, an estimate of real area of contact from the measured contact resistance is discussed. The fabrication methods elaborate on electroforming nickel fibers using commercially available nano-porous filters. Finally, experimental results of contact resistance between a spherical tip probe and arrays of nickel nanowires as well as the contact resistance between a flat tip probe and arrays of nickel nanowires are presented. From these experimental results, we show resistance reduction by a factor of more than 20 at a load of 10 mN or less, compared to contact with a flat sheet, and a reduction by a factor of 3 using a spherical probe.