Traditional hypodermic needles may be displaced by laser powered needles in delivering vaccines, annual flu shots and other medications. According to experiments conducted on guinea pigs by researchers at Seoul National University, needles can be fitted with erbium-doped yttrium aluminum garnets, or Er:YAG, to morph into laser needles. Er:YAG technology is nothing new to patients as it is commonly used by dermatologists, particularly for facial cosmetic treatments.
The Er:YAG laser is designed to propel a minute but precise dose of liquid drug to a highly specified depth of penetration underneath the skin with the appropriate force. The laser operates with multiple pulses that last no more than 250 millionths of a second each. These fleeting pulses are administered at lower energy, thereby delivering a significantly higher dose than alternative methods of drug administration.
These laser pulses generate 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 only slightly thicker than a human hair.
Behind the miniature jet nozzle is a small chamber containing a liquid form of the drug to be injected, and behind that is another for the “driving” fluid, in this case, water. A flexible membrane keeps the two liquids separate.
Since the speed of the fluid and narrowness of the nozzle create jet pressure that is higher than the tensile strength of skin, Er:YAG laser needles should be painless. Another reason that Er:YAG laser needles should be pain-free is that they aim for the epidermal layer just under the surface of the skin, where there are no nerve endings.Laser Needles,