| Abstract
| - Superwetting of structured surfaces, sometimes referred to as hemi-wicking, was studied both experimentally andtheoretically. Structured substrates with regular arrays of square pillars or frustra were machined from graphite blocksand then treated to render them lyophilic. Liquids spread over these surfaces to produce noncircular wetting areas.If the channels between the features were made shallower or narrower, liquids wicked more and spread over a largerarea. The inherent wettability of the graphite was relatively unimportant; large differences in the contact angles hadlittle influence on the spreading. Practically, this means that, to achieve extensive coverage, near-zero contact anglesare not required. A combination of the appropriate surface structure and moderate inherent wettability can effectivelyflatten liquids, spreading them over very large areas.
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