Japanese scientists have developed a “slightly sweaty” robotic finger covered in live skin, in an advance they say brings human-like robots one step closer.
The finger, which has been shown to be able to heal itself, is seen as an impressive technical feat that blurs the line between living flesh and a machine. But scientists are divided over whether people will raise their body temperature to lifelike anatomy or find it frightening.
“We were surprised by how well the skin tissue fits into the surface of the robot,” said Shoji Takeuchi, a professor at the University of Tokyo, who led the work. “But this work is just the first step towards creating robots covered with live skin.”
The team argues that more realistic humans would be able to interact with people more naturally in a range of roles, including in the nursing care and service industry.
“I think live skin is the ultimate solution to giving robots the look and feel of living things because it’s exactly the same material that covers animals,” Takeuchi said. He added that such developments have the potential to “build a new relationship between humans and robots”.
Scientists have previously produced skin grafts — layers of skin that can be sewn together in reconstructive surgery, for example — but they have struggled to create live skin on dynamic 3D objects.
In the latest work, the team first immersed a robotic finger in a cylinder filled with a solution of human dermal collagen and fibroblasts, the two main components that make up the connective tissues of the skin. This coats the surface like a primer, providing a seamless layer for the next layer of cells – human epidermal keratinocytes – to adhere to. Bending the finger back and forth caused natural-looking wrinkles on the knuckles and upon injury, the recreated skin can self-heal like humans with the help of a collagen bandage and feel, according to scientists, like real skin.
The finger is a work in progress: his skin is much weaker than normal skin and must remain moist because without a circulatory system, the cells would die if dried out. Its movements are clearly mechanical.
“The finger looks a little sweaty from the cultured middle,” Takeuchi said. “Since the finger is powered by an electric motor, it is also interesting to hear the motor clicking sounds in unison with a finger that looks like a real finger.”
However, experts say it’s this combination of realism and mechanics that can elicit a feeling of disgust, known as the “super-valley” effect.
Dr Burku Orgen, from Bilkent University in Ankara, Turkey said: “It is possible that the human-like appearance [of some robots] You raise some expectations but when you don’t meet those expectations, you find them frightening or intimidating.”
“It seems to be a great technical innovation,” said Professor Fabian Grabenhorst, a neuroscientist at the University of Oxford who also studies the so-called uncanny valley effect.
He agreed that people may have an initial negative reaction to the combination of human and robot features, but said research has shown that response can change depending on interactions with the robot. “At first people may find it strange, but it is through positive experiences that it may help people overcome these feelings.”
The team now plans to integrate more complex functional structures within the skin, such as sensory neurons, hair follicles, nails and sweat glands. They also work on a robotic face covered with leather. Progress is described in the journal issue.