A short commentary on the two research articles published in Friction in 2021 is presented. Both articles reported experimental results of applications of laser surface texturing technology to the raceway of rolling element bearings. After briefly reviewing the main findings of the articles, the arguable problems and distinctions between the two articles are pointed out.

Adhesive and corrosive wear at microscales are quantitatively distinguished in lifetime tests of resonant bulk-fabricated silicon microelectromechanical systems (MEMS). By analyzing the oscillation decay characteristics in different vapor environments, we find that wear is dominated by asperity adhesion during the initial stages of rubbing in dry N₂ or O₂/N₂ mixtures; in these situations the transient wear rate is inversely proportional to the wear depth. But in water or ethanol vapors, chemical reactions between the corrosive adsorbed layer and the silicon substrate limit the wear rate to a constant. These observations are consistent with atomic explanations. The differences between adhesive and corrosive wear explain the advantages offered by lubricating with alcohol vapors rather than using dry environments for tribo-MEMS devices. Compared to ethanol, the relatively poor anti-wear effect of water vapor is explained by aggressive and rapid tribo-reactions.