The very thought of needles makes many squeamish, but scientists from the Seoul National University in South Korea hope to alleviate those fears by replacing the sharp metal with laser-powered injections. As described in a paper published in the Optical Society's Optics Letters journal, the system uses laser pulses to create a precisely controlled stream about the width of a human hair. The resulting injections target the epidermal layer — a portion of the skin that has no nerve endings — to create what researcher Jack Yoh calls a "completely pain-free" experience. The high-pressure streams are able to inject drugs without damaging skin tissue, similar to the needle-free technology being created by researchers at MIT.

Speaking with the Optical Society, Yoh explains that "The impacting jet pressure is higher than the skin tensile strength and thus causes the jet to smoothly penetrate into the targeted depth underneath the skin, without any splashback of the drug." Yoh, a professor of mechanical and aerospace engineering, is developing the technology with the help of Seoul National University graduate students. The team is currently working to find a way to produce low-cost injectors and hopes to eventually use the technology for mass vaccinations for children.