Using nothing but light and bioink, scientists were able to directly print a human ear-like structure under the skin of mice. The team used a healthy ear as a template and 3D printed a mirror image of that ear—tissue layer by tissue layer—directly onto the back of a mouse.

All without a single surgical cut.

If you’re thinking that’s super creepy, yeah…I’m with you. As a proof-of-concept, however, the team shows that it’s possible to build or rebuild tissue layers, even those as intricate as an ear, without requiring surgical implant. This means that it could one day be possible to fix an ear or other surface tissue defects—either genetic or from injuries—directly at the injury site by basically waving a sophisticated light wand.