Research on the Response Behaviors of Microdroplet/ Superhydrophobic Interface Forces under Voltage

doi:10.3901/JME.2022.17.240

Abstract

Abstract: Adjusting the solid/liquid interfacial behaviors has strong application prospects in the fields of microfluidic and lab-on-a-chip et al. The interaction forces and adhesion behaviors at microdroplet/superhydrophobic interface under voltage are systematically studied using a solid/liquid interface behavior measuring device. Results showed that the interaction forces are composed of a wetting force, a maximum force and a separation force under voltage. The wetting force, the maximum force and the separation force varied with voltage. In the static region, the forces increased slowly. In the transition region, the forces increased sharply, however, the forces remained unchanged in the saturation region. The variation of the forces is depended on the adhesion energy between droplet and solid under voltage. Theoretical analysis indicated that the adhesion energy is proportional to the electrical properties of the superhydrophobic surface and the square of the voltage. Further analysis found that the experimental adhesion energy is greater than the theoretical value, which might relate to the transition of the wetting state of droplets under voltage. An electrowetting hysteresis experiment verified that the variation of adhesion energy was related to the wetting state of droplet under voltage. The results show that the interaction forces and adhesion behaviors of the microdroplet/superhydrophobic interface can be effectively adjusted by voltage. The founding is expected to provide a guidance for controlling liquid/solid interfacial behaviors and to enrich the microfluidics theory.

Key words: solid-liquid interface, adhesion, voltage, superhydrophobic surface, micro-droplets

CLC Number:

TH136

ZHANG Yafeng, TANG Cheng, DONG Conghui, YU Jiaxin. Research on the Response Behaviors of Microdroplet/ Superhydrophobic Interface Forces under Voltage[J]. Journal of Mechanical Engineering, 2022, 58(17): 240-248.

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