Volume of liquid deposited per single event electrospraying controlled by nozzle front surface modification

Single event electrospraying (SEE) is a method for the on-demand deposition of picoliter volumes of liquid. To investigate the influence of the size of the meniscus on the volume deposited per SEE, glass capillaries were used with and without an anti-wetting coating comprising a self-assembled 1H,1H,2H,2H-perfluorodecyltrichlorosilane-based monolayer to control the meniscus size. The deposited volume was determined experimentally and we developed a model that incorporates electrostatics and electrodynamics on the one hand, and hydrostatics, fluid dynamics, and surface tension effects on the other hand. The volumes deposited from both a capillary with unmodified nozzle front (large meniscus) and from a capillary with a modified nozzle front (small meniscus) can be predicted by the theoretical model.