Electrohydrodynamic effect on sessile droplet evaporation: A review

Droplet evaporation is a ubiquitous and fundamental physical process that is highly sensitive to external fields. This paper reviews the underlying mechanisms and various phenomena associated with sessile droplet evaporation under the influence of an electric field, with a particular focus on electric deformation, electrowetting, and internal convection. When an external electric field is applied, polarization forces deform the droplet, leading to a reduction in the solid–liquid contact angle and an enlargement of the contact area, thereby accelerating the evaporation process. However, when the electric field is excessively strong, the resulting large deformation can increase thermal resistance, ultimately inhibiting evaporation. In addition, electrohydrodynamic effects induced by electric stresses generate circulation vortices within the droplet, enhancing surface heat flux and promoting evaporation. When alternating electric fields are applied, droplet oscillations further drive internal flow and surface deformation, modulating both heat and mass transfer characteristics. From a molecular perspective, polarization-induced charge asymmetry, the disruption of hydrogen bonding networks, and electrophoretic migration of molecules collectively contribute to variations in sessile droplet evaporation behavior.