理論モデルと実験検証の比較に基づく微細表面構造上における撥水性発現機序の予想

抄録

The micro-surface structure influences the contact angle of droplets. Recent improvements in microfabrication technology have led to many industrial applications based on the perspective of biomimetics. On the other hand, there are not enough theoretical considerations. Only two states, Cassie-Baxter and the Wenzel states have been presented. Experimentally, the contact angle is expected to take an intermediate state between the two states, or to mutually shift between the two models. However, most of the previous studies based on biomimetics, have focused on simple mimicry of biological surfaces that exhibit superhydrophobic properties or aiming for a contact angle closest to the ideal value, and have not yet proposed an industrially appropriate micro-surface structure. In our experiments, we fabricated a simple micro-surface structure on a specimen of polydimethylsiloxane (PDMS). The micro-surface microstructure consists of micropillars arranged in a plane-fillable pattern. The distance between the pillars can be continuously deformed by stretching the specimen. By carefully investigating the change in contact angle with the change in elongation ratio, we aim to find an experimental formula to compensate for the deviation of the experimental value from the theoretical value. Our final goal is to elucidate the mechanism of water repellency on micro-surface structures based on the comparison of theoretical models and experimental verification.