A new preparation scheme for the wettability-patterned copper surfaces and its applicability

Droplet control technology has broad application prospects and the wettability-patterned surface is a popular way to realize it. However, the existing preparation methods are either not suitable for copper or not suitable for its batch fabrication. In this paper, three specific preparation schemes with different effects are proposed for the wettability-patterned copper surfaces. Then the influences of preparation conditions on the contact angle are investigated. Using the selected preparation conditions, the effects among different preparation schemes are compared and the wettability-patterned copper surface prepared following preparation scheme 3 shows the best effect. Subsequently, according to different design purposes, the motions and spreading of water droplets on wettability-patterned copper surfaces with four new patterns are observed. It indicates that the hydrophilicity/hydrophobicity and directional liquid transport functions basically reach the pre-designed effects, which verifies the applicability of preparation scheme 3 on the wettability-patterned copper surfaces with different patterns for droplet control. Finally, compared with the existing preparation schemes, only the new preparation scheme proposed in this paper is conducted under room temperature and it does not require any special equipment. What's more, its preparation time is the shortest (18 min). Hence, it is suitable for batch fabrication, which can extend the applications of wettability-patterned copper surfaces.