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Tribological tests are adopted to estimate the kinetic friction coefficient (COF) of the material of interest according to the American Society for Testing and Materials (ASTM) standard. Typically, for the measurement process, several replicas, as well as a postprocessing data treatment, are necessary to take into account the observed casual variability of the measurand. This article describes a statistical approach aiming to highlight the running-in phase and the most significant time intervals during the steady-state for each test replica. A two-steps procedure based on the adoption of the bootstrap method allows the automatic detection of the running-in time interval and the outlier filtering of the steady-state. Experimental activity has been carried out by performing multiple tests through the ball-on-flat tribometer in order to verify the improvement allowed by the authors’ proposal about the dry friction COF measurement in terms of both accuracy and repeatability. [ABSTRACT FROM AUTHOR]

A custom microdevice was used to study the effect of hydrofluoric acid processing on the force of adhesion at a silicon sidewall contact interface. Devices exposed to acidic etchant solution for a longer period of time were found to have a significantly higher surface roughness and a lower adhesion force. These results are attributed to an accelerated formation of porous silicon caused by a release etch-induced galvanic couple between the structural silicon and the gold electrical contact pads. Experiments are interpreted in light of galvanic corrosion mechanisms and the effect on the principal components in nanoscale adhesion.\hfill[2012-0276] [ABSTRACT FROM PUBLISHER]