Millions of injections are given annually, from annual flu shots to childhood immunizations. However, while hypodermic needles deliver controlled, precise injections, the pain they deliver continues to make them unpopular among recipients, especially children.
Now, a new laser-based system, being developed by mechanical and aerospace engineers at Seoul National University in South Korea, could painlessly blast microscopic jets of drugs into the skin.
The system uses a laser similar to the type most commonly used by dermatologists, combined with a small adaptor that contains the liquid drug to be delivered, plus a chamber containing water that acts as a “driving” fluid. Each laser pulse, which lasts just 250 millionths of a second, generates a vapor bubble inside the driving fluid, causing the drug to be ejected from a miniature nozzle in a narrow jet a mere 150 millionths of a meter in diameter.
Since they aim for the epidermal layer, which is located closely to the skin surface, this region of the skin has no nerve endings, so the method should be completely pain-free, they say.
