with gradients in nanometer-scale surface topography have been prepared by sandwiching two hexadecanethiol (C16) self-assembled monolayers between two gold films, one of which had been deposited at a fixed angle of incidence (40°), the other at an angle varied from 48° to 58°. (N. L. Abbott et al., September 3, Adv. Mater. 2002, 14, 1224-1227)