Fabrication of superhydrophobic bionic surface integrating with VOF simulation studies of liquid drop impacting

Abstract

Superhydrophobic surface has wide application in self‐cleaning, anti‐pollution, anti‐adhesion, drag reduction, but the stable and efficient manufacture of bionic superhydrophobic surfaces is a challenge. We have reproduced the microscopic structure of natural plants and achieved superhydrophobic surface preparation without chemical modification by mechanical process. This program need many experiments to generate processing parameters based on the bionic surface structure. To solve this problem, based on the natural Green Bristlegrass superhydrophobic surface, an optimized bio‐inspired striped configuration was presented and the computational fluid dynamics approach was integrated into the fabrication, which was estimated the superhydrophobicity of bio‐inspired surface. The volume of fluid (VOF) model and the Level Set function were used to determine the position of the interface during the liquid impact process by solving the change of the volume fraction of each phase in the mixed fluid, thus tracking the gas–liquid phase interface. According to the simulation of striped surface structure, we have processed the bionic samples successfully and they showed an excellent superhydrophobic property, the contact angle was 154° ± 2° and the sliding angle was <5°. The contact time of bionic sample was 12.8 ms. This article used the VOF simulation method to evaluate the design and parameters of the structure, so that the selection of processing parameters were more optimized. Furthermore, the study was essential to access the bio‐inspired design and fabrication procedure of superhydrophobic surface.

One-level microstructure-arrayed hydrophobic surface with low surface adhesion and strong anti-wetting function

“…In order to verify the theoretical prediction, numerical calculations are systematically carried out based on the powerful software 'Fluent', which has been used to study processes such as droplet impacting and droplet merging [63][64][65][66][67][68][69][70].…”

Superhydrophobic materials used for anti-icing Theory, application, and development

“…The spherical droplets mingled with the dust attach on the surface of the lotus leaf and tumble down, leaving a clean surface of the lotus leaf. In nature, many plants and animals have SHS similar to lotus leaf, such as rose petals ( Bhushan and Her, 2010 ; Chen et al., 2018 ), clover ( Liu et al., 2019a ), taro leaves ( Chen et al., 2017 ; Yi et al., 2019 ), water striders ( Gao and Jiang, 2004 ; Lu et al., 2018 ), butterfly wings ( Zheng et al., 2007 ), the penguin body feather ( Wang et al., 2016 ), and so on ( Figure 1 ). Inspired by different plants and insects, researchers have developed many SHSs.…”

“… (C) Water droplet beading on green Bristlegrass; (inset of (C)) a water CA of green Bristlegrass is 153°, showing a good SH property. Image reprinted with permission from Liu et al. (2019a) .…”

Bionic microstructure on titanium alloy blade with belt grinding and its drag reduction performance

“…The machined surface has good hydrophobic property and can maintain Cassie state steadily. Liu et al 12 discussed the characteristics of biomimetic hydrophobic surfaces, carried out a lot of experiments to prepare biomimetic surfaces, and discussed the hydrophobicity of biomimetic structures under different parameters through simulation analysis.…”