Lubricant evolution and depletion under laser heating: a molecular dynamics study
Abstract
Understanding the performance of polymeric perfluoro-lubricants under femtosecond laser irradiation is of great fundamental importance in enhancing the stability and durability of micro- and nano-devices. In this paper, molecular dynamics simulations of perfluoropolyether are carried out to investigate the evolution and depletion of molecularly thin lubricants when subjected to laser heating. Ultrathin perfluoropolyether lubricant films are modeled by the coarse-grained bead-spring model and are coated on an inert substrate. Periodical surface morphology and layered film structure are formed in the equilibrium lubricant system due to the polar interaction of functional beads. It is found that the lubricant undergoes severe depletion with an increase in laser heating duration, resulting in aggravated lubricant