An electrohydrodynamic method known as harmonic electrical spraying is utilized for producing collimated beams of monodisperse, uniformly charged molten metal particles. The uniform particles are regularly emitted from an electrically stressed meniscus at a capillary tip. Data are presented showing the dependence of the process on applied voltage and reservoir pressure. An energy balance equation for the process is developed, and from this equation the velocity of the emitted particles is computed and compared with experimental values.

A method is described for producing collimated beams of monodisperse, uniformly charged liquid particles. The method utilizes the harmonic electrical spraying of liquids, wherein uniform particles are regularly emitted from an electrically stressed meniscus at a capillary tip. Data are presented showing the dependence of this process on capillary diameter, reservoir pressure, and applied voltage. It is expected that focused beams of particles produced by the harmonic spraying process will facilitate the selective coating and abrading of solid surfaces within microscopic tolerances. In addition, the process provides a convenient method for producing monodisperse aerosols of known particle diameter.

A general theoretical analysis of the behavior of a conducting liquid drop in an electric field is presented. Numerical results are given for the quiescent distortion, resonant frequencies, and normal modes of oscillation of the drop as functions of applied field strength.

An inexpensive device is described for producing uniform liquid drops which are colinear in trajectory. The device uses both an electrically induced dripping mode and a harmonic electrical spraying mode to achieve continuously variable drop diameters over a 20 to 1 range. Because the drops are uniformly charged (∼10−10 C), their velocity and trajectory can be readily varied using inexpensive electrical means.

A general expression is derived for the change in electrostatic energy that occurs when an axially symmetric, deformed conducting sphere (i.e., a closed surface which can be represented in terms of a Legendre polynomial expansion) is inserted in an axial electric field. These results overcome the principal obstacle which heretofore has precluded analysis of the dynamic behavior of a conducting liquid drop in an electric field.