A device for delivering a substance to a target body has a needle-free injector (1000) to inject the substance into the target body. The needle-free injector (1000) includes plural independent jet actuators (1002) to inject individually controlled jet streams (1006). The needle-free injector (1000) is positionable proximate to a surface (155) of the target body. Each jet actuator (1002) has a reservoir (113), a nozzle (114) coupled to the reservoir (113), and a controllable electromagnetic actuator (125) in communication with the reservoir (113). The electromagnetic actuator (125) receives an electrical input and generates a mechanical force which produces a pressure within the reservoir (113), causing ejection of the substance from the reservoir (113) through the nozzle (114).
