A novel micro-friction measuring-head using force-feedback compensation

A novel micro-tribometry system has been developed specifically for investigating whether the limited dynamic response of conventional instruments might hide functionally important materials behaviour. It is based on a universal measuring head, suitable for use with a wide range of specimen stages, that incorporates a relatively stiff elastic sensing element and actively-controlled electromagnetic force actuation in both axes. This paper first reviews the rationale for the new design and then explains the critical design features. Characterization and calibration are discussed: the prototype unit is aimed primarily at use in the 10 - 50 mN, with a bandwidth of at least 100 Hz. The basic operation and capabilities of the micro-tribometer head are presented by means of demonstration experiments on smooth and relatively rough surfaces