An ejector of liquid material to form spherical particles includes a crucible for retaining liquid material, an orifice area defining at least one orifice, and an actuator responsive to a voltage signal for causing material to be ejected from the crucible through the orifice. A method comprises applying a voltage signal of a first type and a second type to the actuator, causing a material droplet of a first size and a second size to be ejected through the orifice. Alternately or in addition, the orifice area defines a first orifice having a first diameter and a second orifice having a second diameter different from the first diameter, whereby a signal causes a material droplet of a first size to be ejected through the first orifice and a material droplet of a second size to be ejected through the second orifice.