An Oscillation System Based on a Liquid Metal Droplet and Pillars under a Direct Current Electric Field

Abstract

Gallium-based liquid metal is a new class of material that has attracted extensive attention due to its excellent deformation characteristics and great potential in applications. Based on the deformation characteristics of liquid metal droplets, researchers have developed many oscillation systems composed of gallium indium tin alloy (GaInSn) droplet and graphite, or aluminum-doped gallium indium alloy (Al-GaIn 24.5 ) droplet and iron, and so on. Rather than the oxidation and deoxidation mechanisms used in previous systems, an oscillation system that can achieve gallium indium alloy (EGaIn) droplet oscillation with the frequency of 0−29 Hz is designed depending on the interactions between the electric field, pillars, sodium hydroxide, and the droplet. The forces on the droplet are analyzed specifically, which have a great influence on droplet deformation. Additionally, the effects of factors such as voltage, the concentration of sodium hydroxide (NaOH) solution, and droplet size on the droplet oscillation are elucidated based on the force analysis, enabling the flexible control of the oscillation frequency and amplitude of the droplet. This work provides a new perspective on the design of oscillation systems and further enhances our understanding of the deformation of gallium-based liquid metal droplets.

A system for fluid pumping by liquid metal multi-droplets

“…37,38,42,48 However, there is a lack of investigation on other structures. Our previous studies illustrated that pillars effectively restrain the droplets, 39 where the droplets are only tangent to the side edges of the pillars, which can avoid partial obstruction of the droplet surface due to contact with the walls, thereby maximizing the use of the droplet surface. Therefore, a cuboid pump is designed based on the structure of the cylindrical pump, which uses the pillars to restrain droplets (Fig.…”

“…Therefore, single-droplet and multi-droplet cuboid pumps using pillars to constrain droplets are designed in this paper based on our previous study. 39 The influence of AC voltage, DC bias, voltage frequency, solution concentration, and other factors on the pump flow rate is clarified, and the optimal frequency distribution plots for various AC voltage and DC biases are also given. Furthermore, the expression of the solution velocity on the surface of each droplet and the relationship between the flow rate, AC voltage, and the number of droplets are derived.…”