Those of us with an aversion to needles can soon go to the doctor with a little less trepidation. That is if a new device developed by a team of MIT researchers becomes available at your local medical facility. The device uses a Lorentz-force actuator to create an adjustable high-pressure jet that is ejected out of a nozzle as wide as a mosquito's proboscis, penetrating the skin to deliver highly controlled doses at different depths.
While jet-injectors have been commercially available for decades, they typically rely on compressed air or gas cartridges to power each delivery. The Lorentz-force actuator - a small, powerful magnet surrounded by a coil of wire that's attached to a piston inside the drug ampoule - is powered by an electric current. Able to pressurize a drug up to 100 megapascals in under a millisecond, the device is capable of injecting high pressure doses at almost the speed of sound in air, (about 314 m/s or 1,126 ft/s). By altering the electric current, the velocity of the delivery can even be changed mid-injection.
To modulate the current and velocity of a delivery, the MIT team has generated various pressure profiles for the device. These generally include two distinct phases - a high-pressure phase to breach the skin and reach the desired depth, followed by a lower-pressure stream that allows the medicine to be absorbed by the surrounding tissue. The pressures can also be modified to suit different skin types.
“If I’m breaching a baby’s skin to deliver vaccine, I won’t need as much pressure as I would need to breach my skin,” says Catherine Hogan, a research scientist in MIT’s Department of Mechanical Engineering. “We can tailor the pressure profile to be able to do that, and that’s the beauty of this device."