Retraction control of an impacted dielectric droplet through electrical pressure

Abstract

When a deposited dielectric liquid interface is exposed to a unipolar ion injection in a gaseous medium, the liquid expands over the grounded substrate due to the squeezing force of electric pressure (S. R. Mahmoudi, K. Adamiak, G. S. P. Castle, Spreading of a dielectric droplet through an interfacial electric pressure, Proc. R. Soc., 2011, 467, 3257–3271). A new active method based on the concept is proposed to control the deposition of an impacted dielectric droplet. An electric pressure resulting from the electric surface charge produced by corona discharge squeezes the droplet interface towards the grounded substrate and generates a resistance against the droplet retraction. It is demonstrated that the electrical pressure effectively suppresses the droplet retraction at voltages above the corona discharge threshold.