Tailorable and Repeatable Normal Contact Stiffness via Micropatterned Interfaces

Abstract

An approach to producing interfaces with tailored and repeatable normal contact stiffness using micropatterned surfaces is developed. A finite element model is first used to design square wave interfaces having a range of stiffnesses, and these are fabricated in polycarbonate via a microfabrication process. Results demonstrate that the contact stiffnesses of the fabricated interfaces are both tailorable and repeatable. The approach can be broadened to other materials and is useful for applications requiring specified interface stiffness. Finally, even with these deterministic interfaces, we show that low levels of roughness on the surface features are sufficient to produce a load-dependent contact stiffness at lower loads. Therefore, tailorability is mostly applicable above this limit where total contact stiffness converges to a load-independent value.