Military scientists have invented spray-on skin: By applying a thin film of stem cells over a burn victim's wound, they can regrow skin in a matter of days. National Geographic documents one man's recovery.

We first heard about the skin cell gun three years ago, when it was still just an idea. Since then, the futuristic procedure has been used a dozen times.

Jörg Gerlach, a researcher with the McGown Institute for Regenerative Medicine, explained the technology to National Geographic's Explorer: Doctors mix stem cells from the patient's healthy skin with water to create a serum, which they then load into the skin cell gun and apply "like paint spray" to the wounded area. The result is likened to a salamander growing a new tail: The tissue regenerates. A clip is below. Warning: It contains graphic medical images.

Matthew Uram, a Pennsylvania state police officer, is one of the first people to use the gun. After suffering third-degree burns from a bonfire gone awry, Uram's doctors used the skin cell gun on him: "They did it on a Friday, and my follow up was that Monday, and the burn unit said it was healed. Completely healed." He described the technology as "like Star Wars." [National Geographic]