Needle-Free Injections This device delivers a high-velocity jet of liquid that breaches the skin at the speed of sound. MIT BioInstrumentation Lab
Whether you’re at the doctor’s office or taking medicine at home, future injections could be a lot less painful with this new gadget developed at MIT. Instead of a sterile metal point penetrating your skin, it fires a jet of medicine through your skin at the speed of sound.
It’s similar to a normal syringe, except instead of a needle plunger, it uses a Lorentz force actuator, made from a magnet surrounded by a conductive coil. When a current is turned on, the magnetic field interacts with the current to produce a force. That force kicks a piston, which ejects a drug that has been embedded inside the capsule. The speed of the ejection and the depth it will reach can be controlled by altering the current.
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To penetrate the skin, the ejection happens at ultra high speeds, almost equivalent to the speed of sound through air. The drug flows through an opening that’s about as wide as a mosquito proboscis, according to MIT News.
Researchers led by Ian Hunter and Catherine Hogan tested a prototype device with two different velocities: One can breach the skin and reach deep into tissue, and another can deliver drugs more slowly, so they can be absorbed by the skin. Different people would need different piston velocities — “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,” Hogan said.
That’s key for this device, because other existing types of jet injectors are limited by their design. They may use a spring-loaded injector, which can only work at one velocity, for instance.
While the supersonic variable-speed delivery is new, it’s hardly the first device to seek elimination of the hated hypodermic needle. Several other alternatives exist, like super-thin microneedles, as wide as a human hair, and a microneedle patch, which deliver drugs with no pain and simply dissolve on the skin. But again, those would require a drug-specific design.
For the average trypanophobe, the prospect of sticking oneself with a needle is anathema, so a more universal system like this could improve patient compliance with the doctor’s orders. Plus, the researchers also point out, it could prevent needle-stick injuries by health care workers and others. The Centers for Disease Control and Prevention says hospital workers accidentally prick themselves 385,000 times per year. Not so with a jet injector.
Watch Hogan and Hunter explain further in the video.