Scientists covered a robot finger in living human skin

Robots can now be covered in living skin grown from real human cells to make them look more like us.

As robots increasingly take on roles as nurses, care workers, teachers and other jobs that involve close personal contact, it is important to make them look more human so we feel comfortable interacting with them, says Shoji Takeuchi at the University of Tokyo in Japan.

At the moment, robots are sometimes coated in silicone rubber to give them a fleshy appearance, but the rubber lacks the texture of human skin, he says.

To make more realistic-looking skin, Takeuchi and his colleagues bathed a plastic robot finger in a soup of collagen and human skin cells called fibroblasts for three days. The collagen and fibroblasts adhered to the finger and formed a layer similar to the dermis, which is the second-from-top layer of human skin.

Next, they gently poured other human skin cells called keratinocytes onto the finger to recreate the upper layer of human skin, called the epidermis.

The resulting 1.5-millimetre-thick skin was able to stretch and contract as the finger bent backwards and forwards. As it did this, it wrinkled like normal skin, says Takeuchi. “It is much more realistic than silicone.”

The robot skin could also be healed when it was cut by grafting a collagen sheet onto the wound.

However, the skin began to dry out after a while since it didn’t have blood vessels to replenish it with moisture.

In the future, it may be possible to incorporate artificial blood vessels into the skin to keep it hydrated, as well as sweat glands and hair follicles to make it more realistic, says Takeuchi.

It should also be possible to make different skin colours by adding melanocytes, he says.

The researchers now plan to try coating a whole robot in the living skin. “But since this research field has the potential to build a new relationship between humans and robots, we need to carefully consider the risks and benefits of making it too realistic,” says Takeuchi.