For most people, a scratch or wound that heals after a few days is fairly unremarkable, even expected. After all, it’s something that’s happened as long as we can remember.

In the world of medicine, self-healing prosthetics are still in their pioneering stages – but researchers at Stanford University have just made a breakthrough with synthetic skin that not only self-heals, it has a sense of touch.

In 2008, scientists at EPSCI Paris Tech created a kind of rubber that could be torn, re-sealed, torn, and re-sealed again just by pressing the edges together. That takes care of the healing part, but the polymer still couldn’t relay touch, the series of electrical impulses moving from the skin to the brain. Unfortunately, rubber is no good at transferring electricity, but metal is.

Scientists have been able to create thinner-than-paper nanotechnology using metals like gold and silicon, but they crack if you try to stretch them like human skin, so a kind of polymer is still necessary. To fix the conductivity problem researchers combined conductive metal with resilient polymer, adding nickel atoms to the rubberized material. Electrical impulses could jump from atom to atom, while the polymer could stretch, bend, and – like EPSCI Paris Tech’s creation – heal by just pressing its edges together.

On top of the healing of the actual skin, very little electrical connectivity was lost. Stanford scientists cut the polymer and resealed it with 15 seconds of pressure, and the polymer only lost two percent of its conductivity.

However, this was when the material was cut cleanly with a scalpel. Most wounds tend to be jagged and much less clean, so more testing needs to be done on how the polymer would react in those situations.

Photo: wolfgangfoto/Flickr