The contact angle of droplet on a sample before and after ion beam treatment. For static mode, (a) the droplet image on the sample before ion beam treatment, (b) the droplet image taken parallel to the ion beam-irradiated direction after ion beam treatment, and (c) the droplet image taken perpendicular to the ion beam-irradiated direction after ion beam treatment. For dynamic mode, (d), (e), and (f) show that the angle difference is smaller for the direction perpendicular to the ion beam exposure.
Choi et al. Nanoscale Research Letters 2012 7:63 doi:10.1186/1556-276X-7-63