"You don't feel when the mosquito inserts the proboscis into your skin because it's so very narrow. Our jet is of a similar diameter," Professor Hunter told MIT News.
The jet is so narrow, in fact, that drugs can be injected through the eye into the retina and through the tympanic membrane into the middle and inner ear.
"And we've also done something that we think is pretty cool: we can take a drug in powdered form [and] put it in this device.
"The device, because of its very, very fast response, is able to vibrate that powder so it behaves like a liquid and then we inject it into tissue as though it was a liquid, even though it's a powder," Professor Hunter said.
Dr Andrew Taberner from the University of Auckland's Bioengineering Institute was in charge of the New Zealand part of the project.
He was one of the original team at MIT who started the research, which was how the Auckland institute came to be involved.
The design is built around a mechanism called a Lorentz-force actuator - a small, powerful magnet surrounded by a coil of wire attached to a piston inside a drug ampoule (a small sealed vial).
When current is applied, it interacts with the magnetic field to produce a force that pushes the piston forward, ejecting the drug at very high pressure and speed through the ampoule's nozzle. The researchers hope that among its other benefits, the technology will cut the number of doctors and nurses who accidently prick themselves with needles.
Catherine Hogan, a member of the MIT research team, said it was hoped the device would help people with a phobia of needles as well as easing the discomfort of those who have to regularly inject themselves with drugs such as insulin.
