Review of electrospray cooling and charged droplets heat transfer

Electrospray is a well-established technique with wide-ranging applications in fields such as mass spectrometry, nanomaterial preparation, colloidal thrusters, clean combustion, and agricultural plant protection. Recently, it has shown great potential for dissipating high heat flux, a process known as electrospray cooling. In this method, an external electric field charges a liquid, causing it to break apart into ultrafine droplets. These charged droplets are then accelerated toward a heated surface, which enhances the interaction between the droplets and the surface, thereby improving heat transfer efficiency. This paper provides a state-of-the-art overview of electrospray cooling. It focuses on its electrohydrodynamic (EHD) fundamentals, the key factors that govern cooling performance, and the heat transfer enhancement mechanisms of charged droplets. We also discuss the challenges and future opportunities for electrospray cooling applications. Ultimately, this review aims to inspire novel EHD-enhanced thermal management strategies for next-generation, high-performance equipment.