Actuation technique of liquid metal in thermal management: A review

Liquid metal-based thermal management technology has broad application prospects in the heat transfer controls of high-power electronic devices and energy storage units. The low viscosity and high thermal conductivity allow the liquid metal to function as a coolant and a thermal interface material, catering to different heat transfer requirements. However, due to the limitations of heat source temperature and heat transfer power range, liquid metal-based thermal management system still faces some issues, especially the actuation of liquid metal. The precise control of the movement behavior of liquid metal fluids or droplets is the most critical technology to ensure the normal operation of thermal management systems. Currently there is a lack of comprehensive summarization on liquid metal actuation technique. This review aims to initially explore the physical and chemical properties of liquid metal, followed by an investigation into various liquid metal actuation techniques based on different mechanisms. This review provides an overview of the characteristics and limitations of various driving methods for the liquid metal in thermal management, including electromagnetic driving, thermal driving, electrochemical driving, and other approaches. The future development trends of the liquid metal driving technology in various thermal management scenarios were discussed comprehensively, providing guidance for the selection of driving forms for liquid metal-based thermal management systems.