One step closer to Star Trek, painless injections

Remember the syringe looking device that made a hiss and allowed Dr. McCoy to sedate folks? It looks like we might be avoiding needles and using lasers (so maybe Dr. Evil is happy somewhere) to deliver medicines. And it may be pain-free.

A series of very short laser pulses, lasting no more than 250 millionths of a second each, generates a vapor bubble inside the driving fluid. The bubble creates a pressure or elastic strain on the membrane, which forces the drug to be ejected through the tiny nozzle as a narrow jet no more than 150 micrometers (millionths of a meter) wide, or slightly thicker than a human hair.

Yoh explains that the jet pressure is higher than the tensile strength of skin, so it penetrates smoothly into the targeted depth underneath, causing no splashback.

The team has tested the device on guinea pig skin. This showed the jet drives the drug up to several millimeters under the skin, without damaging surrounding tissue.

The speed and narrowness of the jet should be enough to make the procedure painless, says Yoh. But just the fact they are aiming for the epidermal layer just under the surface of the skin, about 500 micrometers down, where there are no nerve endings, should already ensure it is “completely pain-free”.

The hope is that the device may be developed so that it could be used for mass vaccinations.