Electrically Driven Digital Printing of Particulate Matter

Particles can be individually placed on a surface by controlling particle ejection from an orifice. The control can be implemented by adjusting local electric or magnetic fields at or near the point of ejection. In one aspect, a method of delivering a particle can include providing a liquid including a particle to an exit orifice, sensing a condition at a meniscus of the liquid at the orifice, and applying an electromagnetic signal near the orifice for timed particle ejection based on the sensed condition to deliver the particle from the orifice after applying the electromagnetic signal.