| 초록 |
In nature, some creatures show special wetting property known as omniphobicity. For example, Springtails possess an array of re-entrant posts on their skin which facilitates the pinning of liquid-air interface, maintaining the skin dried in both water and oil. Inspired by Springtails, we create array of hammer-like structures to make omniphobic surface by employing unconventional photolithography. During photolithography, oxygen rapidly consumes radicals created by UV-activation. When the diffusion of oxygen is comparable with the consumption, the structure grows a lateral direction from center. We combine the two types of photolithography to create array of hammer-like structures. When the array is rendered to be hydrophobic, the surface exhibits omniphobicity although oils have low contact angle on the flat surface. This is because the bottom edge of hammer head enables the pinning of oil-air interfaces. We measure the contact angles of various liquids and analyze them with models. |
