Accurately Motion Control of a Liquid Metal Droplet in One-Dimensional Fluidic Channel

As an emerging multifunctional material, Gallium based room temperature liquid metal attract particular attentions in a variety of applications due to its mobility and deformability. However, accurately control the motion of a liquid metal droplet still remains unrevealed, which restrict the applications of liquid metal in many fields, especially in micro fluidic applications. In this paper, we propose a hybrid control framework to accurately control the motion of a liquid metal droplet in one-dimensional channel filled with aqueous solution. The electrical field is provided by a simple programmable DC power supply. The dynamic model of a liquid metal droplet immersed in fluidic channels is firstly discussed when the electrical field is applied. Then, a region reaching controller is designed to calculate the desired current input to drive the liquid metal droplet to the destination with vision feedback. The effectiveness of the proposed approach is verified by experiments of accurately control a liquid metal Galinstan droplet to destination inside a PMMA fluidics channels. The proposed control approach may generate profound impacts on developing tiny soft robots or micro-fluidic systems that accurately driven by liquid metal droplets.