Controlled needle-free transport

A needle-free injector device for injecting a substance into a biological body, said device comprising:

• a reservoir for storing the substance;
• a nozzle in fluid communication with the reservoir;
• an electromagnetic actuator in mechanical communication with the reservoir;
• and
• a servo-controller for controlling the actuator, the servo-controller during operation causing the actuator to generate a force which produces a needle-free injection of the substance from the reservoir, through the nozzle, and into the biological body at an injection pressure determined by the force, wherein the servo-controller dynamically varies the force generated by the actuator during the injection to produce an initial injection phase and a subsequent injection phase, and wherein the force generated by the actuator during the initial injection phase is substantially higher than the force generated by the actuator during the subsequent injection phase.

A needle-free injector device for injecting a substance into a biological body, said device comprising:

• a reservoir for storing the substance;
• a nozzle in fluid communication with the reservoir;
• an electromagnetic actuator in mechanical communication with the reservoir;
• and
• a servo-controller for controlling the actuator, the servo-controller during operation causing the actuator to generate a force which produces a needle-free injection of the substance from the reservoir, through the nozzle, and into the biological body at an injection pressure determined by the force, and wherein the servo-controller dynamically varies the force generated by the actuator during the injection to produce a piercing phase followed by a transfer phase, wherein during the piercing phase the force generated by the actuator produces a jet of the substance out of the nozzle for piercing the biological body and wherein during the transfer phase the force generated by the actuator is less than the force generated by the actuator during the piercing phase.