Dynamic spreading characteristics of droplet on the hydrophobic surface with microstructures

The behaviors of droplet impact on the two different microstructures (regular micro-grooved structure and irregular microstructure) exhibiting hydrophobic features are investigated experimentally in this study. Images captured by the high-speed cameras are used to examine the differences between regular and irregular microstructures on the droplet impact process. Dimensionless parameters including dimensionless spreading factor, height and time are introduced to quantitatively analyze the spreading process. The results show that two microstructure accelerate the droplet to reach the maximum dimensionless spreading factor and height, compared with flat surface. It should be also noticed that the droplet breaks up while bouncing on the irregular microstructure surface, which is because that the sum of kinetic and surface energy is slightly higher than the initial total energy during receding process. This study further shows that the beating phenomenon of the dimensionless height of the droplet impact is developed on the regular micro-grooved structure surface.

Automated summary

Experimental study on droplet impact on two different microstructures (regular micro-grooved structure and irregular microstructure) with hydrophobic features reveals that the regular micro-grooved structure accelerates droplet spreading more effectively compared to the irregular microstructure. It is observed that droplet tends to break up when bouncing on the irregular microstructure surface, while a beating phenomenon of droplet height during impact is developed on the regular micro-grooved structure surface.