Microtribology friction measurements on microtextured silicon

摘要

This paper describes the results of microtribology sliding experiments that were carried out on a range of micropatterned silicon surfaces. The objective of this work was to identify critical pattern features that control friction and fluid interaction on surfaces under a broad range of contact conditions and develop models to explain these relationships. These scratch tests were carried out in air, and with deionised water. Tests were carried out under a range of test loads and speeds, from low to high. It was found that in the dry tests, the measured friction was higher on the patterned surfaces than on the non-patterned surface. For the liquid experiments, there was a reduction in friction in some cases, dependent on the pattern and conditions used, indicating that the liquid acted as a lubricant. The greatest reduction in friction was obtained with a herringbone pattern aligned perpendicular to the direction of travel of the probe. However, for higher load conditions, high friction coefficients were measured for many of the patterns. The surfaces of the tested silicon samples were examined with optical microscopy and in high resolution scanning electron microscopy so that the interactions between the probe and the sample could be determined. It was found that the high friction values that had been observed in many experiments were correlated with considerable damage to the structure of the patterned silicon surface