But this isn’t just science fiction. Dr. Jorg Gerlach at the McGowan Institute for Regenerative Medicine at the University of Pittsburgh has created such a device: a "skin gun" that sprays stem cells on burns, which then heal in a matter of days.

Skin grafts are the most common method for treating burns, but those take weeks, even months, to heal. Time is critical, because even with proper care, burns are prone to infection. The skin gun, however, only takes 90 minutes for treatment, and only days for healing. It works like this: first, doctors collect skin stem cells from another part of the patient’s body. Then those stem cells are mixed with a water solution and placed in the skin gun. The gun (which is sort of like an airbrush with computer controls) sprays this solution on the burns.