Living skin helps robot smile in a way that is not at all creepy.

Glistening and pink like extruded edible protein, sure… but at least it’s friendly! NPR uncovers the living skin used to cover robots with a (supposedly) more approachable face:

“In this study, we managed to replicate human appearance to some extent by creating a face with the same surface material and structure as humans,” professor Shoji Takeuchi, the team leader, said in a news release. In the process, he added, “we identified new challenges, such as the necessity for surface wrinkles and a thicker epidermis to achieve a more humanlike appearance.”

The approach promises to make robots more lifelike — and in the future, the researchers say, similar techniques could also be used on humans, in the cosmetics and plastic surgery industries.

To overlay and connect the lab-produced skin on a robotic skeleton, a layer of collagen gel containing cultured human dermal fibroblasts (a type of connective tissue cell) binds to an innovative system of tiny V-shaped perforations in the surface, letting the skin move with the underlying structure without tearing or peeling. The work of muscles — creating a smile, and other motions — is done by actuators.

You can read more of Takeuchi’s work here, in Cell Reports Physical Science.