Laser injection less painful than needles

A laser device for less painful injections has been developed by South Korean scientists.

The system could replace traditional needles, with a jab as painless as being hit with a puff of air.

The laser is already used in aesthetic skin treatments. The aim now is to make low-cost injectors for clinical use.

A team from Seoul National University in South Korea describe the process in the Optical Society's journal Optics Letters.

The researchers write that the laser, called erbium-doped yttrium aluminium garnet, or Er:YAG, propels a stream of medicine with the right force to almost painlessly enter the skin.

The jet is slightly larger than the width of a human hair and can reach the speed of 30m (100ft) per second.