A novel multi-function tribological probe microscope for mapping surface properties

A novel multi-function tribological probe microscope (TPM) has been developed for characterizing surface properties at the micro and nanometre level. The TPM provides four function measurements in a single scan arrangement: surface topography, friction, Young's modulus and hardness of a surface. The measurement is based on point-by-point scanning so that the four measured functions can be correlated in space and in time. It targets an area that is of growing importance to a wide range of technologies where function-orientated surfaces/coatings are in demand. The essential part of the TPM is a force-controlled scanning probe, which has two capacitive sensors. One sensor measures the surface topography and the deformation under a required loading force, and the other measures the frictional force between the probe tip and the surface being scanned. The contact force at the tip is controlled by a magnet/coil force actuator, which applies a constant force in a range of 0.01-30 mN. The topography measurement range is 15 μm with a resolution of 0.1 nm. The scanning area of 100 × 100 μm² is closed loop controlled with an accuracy of 1 nm. Details of the design, testing and calibration of the TPM are presented, as well as applications of the TPM in mapping surface properties of glass, conductive polymer and some engineered surfaces.