It might sound crazy — even blasphemous — but Dutch researchers have developed a micro-injection tattoo machine that doesn’t require any needles at all.
Instead of a traditional needle, an ultrafast liquid jet the thickness of a human hair is used to penetrate the skin. In a new paper, David Fernández Rivas and his colleagues compare this new approach with classic needle technology, using high-speed imagery.
The technique starts with a laser that rapidly heats a fluid inside a microchannel on a glass chip. This fluid is heated above its boiling point, causing a vapor bubble to forms and grows, pushing the liquid out at speeds of up to 100 meters per second. The jet is capable of going through the human skin, and yet it produces almost no pain.
The researchers worked with a number of commercially available inks, finding that their method minimizes skin damage. The device also uses less energy than conventional needles, and produced less waste, as there is no loss of fluids. The risk of contaminated needles is also eliminated.