Next to nothing sticks to the springtail (bottom left), a harmless jumping hexpod (not technically an insect) about the size of the numbers on the face of a penny. Scientists studying the critters discovered that this “omniophobicity” results from two levels of microscopic features on their surface (bottom center and right). The outer surface is covered with 2-µm bumps, which are in turn covered by 200-nm features that resemble a peg with a four-legged cap. This nanosized texture traps air, preventing liquids from fully reaching the surface. As a result, the liquids don’t stick. To replicate the effect on a synthetic surface, Hee-Tae Jung, Geun-Tae Yun and coworkers at Korea Advanced Institute of Science and Technology used a variety of lithographic techniques to cover a polystyrene surface with “serif-T” shaped islands, then wrinkled the surface by heat-shrinking the polystyrene. The resulting material (top) repelled water, ethanol, and ethylene glycol even when the liquids hit the surface at high velocity.
Read the full report here: Sci. Adv. 2018, DOI: 10.1126/sciadv.aat4978
Credit: Science Advances/B. Valentine
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