Application of liquid metal driven-abrasive flow to material removal for the inner surface of channel

Abstract

Gallium-based eutectic liquid metal alloys possess unique properties such as deformability, high electrical conductivity, and low vapor pressure. These characteristics have generated significant interest in their application for stretchable electronics and microelectromechanical systems (MEMS). Precise manipulation of liquid metal within electrolytes is essential to meet specific functional requirements. This study investigates the electrostatic manipulation of liquid metal in an alkaline solution with abrasives for material removal from the inner surfaces of flow channels. The polarization of the double layer at the gallium‑indium alloy and electrolyte interface is analyzed, elucidating the principle of electrolyte propulsion via continuous electrowetting. A theoretical model is developed, and two- and three-dimensional transient and steady-state simulations of the liquid metal-driven abrasive flow are conducted. Results demonstrate that this method effectively removes material from the inner walls of straight channels during cyclic motion. Utilizing continuous electrowetting, an experimental apparatus was designed, where gallium‑indium liquid metal propelled silicon carbide abrasives against PMMA channel walls. Experimental results showed effective material removal, consistent with finite element simulations, confirming the feasibility of this innovative approach.