| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 98 === In nature, the surfaces of lotus leaves which consist of pillar structures with hydrophobic material have the contact angle 150° and sliding angle 5°. However, this kind of structures have some disadvantages, such as low structure strength and hard to replication. And it could be damaged by the high pressure droplet, the surface would be wetted and loss its ability of self-cleaning.
The thesis has designed and manufactured the innovative pattern, “negative lotus structure” which has lotus effect and differs from one in nature. This structure can be distinguished by two layers. One situates at the under layer is the mural structure with incline angle and sealed property that induces the air trapped in it. And another situates at the upper layer is the striped structure with opened property that reduces the contact area of the water drop. From the result of experiment, the mural structures with higher incline angle lead to lower hydrophobicity. The hydrophobic material PDMS with the designed surface has the contact angle 168°, the sliding angle 1°, and the transmittance 70%. It confirmed that the negative lotus structure had greater super- hydrophobicity, self-cleaning ability, and structure strength than nature one.
In view of sealed property of mural structure, we declare that the negative lotus structure has the air spring effect. Via the experiment and analysis results, we could confirm the existence of the air spring effect. In addition, the results which were caused by the effect differed from the formal papers. Therefore, we modify the empirical formula of David Qu?r? to enhance the applicability of the dynamic effect in pillar-like structures.
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