This work applies the molecular dynamics simulation method to study a Lennard-Jones liquid thin film suspended in the vapor and to explore the film thickness effect on its stability. For the accurate estimation of local pressure distributions in the film, an improved method is proposed and used. Simulation results indicate that profiles of the local surface tension distribution vary widely with film thickness, while surface tension values and density profiles show little variation. As the film gets thinner, the two liquid-vapor interfacial regions begin to overlap and liquid-phase molecules in the center region of the film experience larger tension in the direction parallel to the film surface. Such interface overlapping is believed to destabilize the film and the occurrence of film rupture depends on the system temperature and the cross-sectional area of the computational domain.

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The molecular dynamics computational method is used to simulate meniscus formation around an asperity in a rough surface represented as a sinusoidal wave. Simulation results show that the meniscus formation depends on the interaction potential between the solid wall and the liquid atoms. For completely and partially dry substrates a meniscus cannot form around an asperity. For partially and completely wetting substrates the asperity helps to adsorb the fluid atoms and form a meniscus. These simulation results confirm that if the film thickness exceeds a critical value, the capillary pressure contributes strongly to stiction.

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Scientific observations conclude that modern buildings can cause a high number of bird deaths due to birds’ collision with glass windows and glass walls. There are many efforts to put bird-deterrent patterns on glass in order to avoid bird collision. To make the patterns environment-friendly and meanwhile invisible for human eye, we developed a special “first surface PVD coating”. This paper describes a design for bird-deterrent stack from sputter-coating processes, our method to improve the contrast ratio between coated and uncoated area, followed by some discussions on the tunnel-test results.