Using an “underwater superoleophobic pattern” to make a liquid lens array

Abstract

This paper reports a new strategy to realize real liquid lens arrays without evaporation problems based on an underwater superoleophobic-oleophobic heterogeneous pattern. The flat circular region shows an inherent underwater oleophobicity while the femtosecond laser ablated region displays underwater superoleophobicity. In a water medium, the oil droplet is restricted to the untreated circle by the energy barrier at the superoleophobic-oleophobic boundary, thereby forming a convex lens shape by surface tension. The liquid lens array benefits from the surrounding water and then overcomes the problem of evaporation. The shape of the liquid lens can be simply controlled by the designed pattern and the oil volume.

A Review of Femtosecond‐Laser‐Induced Underwater Superoleophobic Surfaces

“…The underwater superoleophobicity was also achieved on other more common glass surfaces such as glass slide by femtosecond laser ablation besides the silica glass surface …”

“…Recently, Yong et al put forward a new strategy to fabricate a liquid lens array based on an underwater oleophobic–superoleophobic heterogeneous pattern . The design principle is shown in Figure a.…”

“…g) Imaging ability of the as‐prepared microlens array. Reproduced with permission . Copyright 2015, Royal Society of Chemistry.…”

“…Inspired by the underwater superoleophobicity of fish scales, various technologies have been developed to fabricate underwater superoleophobic surfaces following the design principle of “from in‐air superhydrophilicity to underwater superoleophobicity,” such as lithography, templating, chemical etching, hydrothermal method, self‐assembly, electrochemical deposition, electrochemical anodization, and spray/dip coating . The same as the superhydrophobic surfaces, the artificial underwater superoleophobic surfaces have also attracted much attention recently owning to their significant applications in antioil coatings, oil/water separation, manipulation of oil microdroplets, self‐cleaning, bioadhesion, antiblocking, guiding the movement of oil droplets, floating on oil, and oil droplets patterning . Underwater superoleophobic surfaces can be successfully prepared by the above‐mentioned traditional methods, but those methods, more or less, have to face their inherent limitations, such as complex fabrication process, tight restriction on special materials, and lack flexibility.…”

Fish scale inspired design of underwater superoleophobic microcone arrays by sucrose solution assisted femtosecond laser irradiation for multifunctional liquid manipulation

“…[1] The state of the oil droplet can be described as Cassie model, [1,27,31,32] and the contact angle can be expressed as 1 cos cos ' − [1] The state of the oil droplet can be described as Cassie model, [1,27,31,32] and the contact angle can be expressed as 1 cos cos ' −…”