Precision friction measurement between ultrathin wire and microprobe

In this study, using an experimental technique based on small-span bending, the friction behaviors of ultrathin Pt wires with the tungsten microprobes have been reported. In the technique, friction force for sliding of a simply supported wire under bending load applied by closely positioned two opposite probes is measured by a microforce sensor. The force sensor is a capacitive detection type double-beam passive cantilever. Specificity of the microforce sensor provides the technological advantage for precise measurement of friction and normal contact forces sequentially under the observation by a high-resolution digital microscope. Static and kinetic frictions due to externally applied force, internal adhesive force and relative motion are successfully determined. Furthermore, the measured friction in wire-probe contact is used in the determination of the mechanical properties of the wire material.