Japanese scientists have developed a “slightly sweaty” robotic finger covered in living skin to get a step closer to truly human-like robots.
Proven to be self-healing, the finger is considered an impressive feat of engineering that blurs the line between living flesh and machine. But scientists were divided on whether people would warm to its lifelike anatomy or find it creepy.
“We are surprised at how well the skin tissue conforms to 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 in living skin.”
The team argues that lifelike humanoids would be able to interact more naturally with humans in a range of roles, including nursing and service industries.
“I think living skin is the ultimate solution to give robots the look and feel of living things because it’s the exact same material that covers animal bodies,” Takeuchi said. He added that such advances have the potential to “create a new relationship between humans and robots.”
The mechanical finger’s human-like appearance can trigger a feeling of revulsion known as the “uncanny valley” effect, experts say. Photo: Shoji TakeuchiScientists have previously made skin grafts – layers of skin that can be sewn together in reconstructive surgery, for example – but have had difficulty creating living skin on three-dimensional, dynamic objects.
In the latest work, the team first dipped the robotic finger into a cylinder filled with a solution of collagen and human dermal fibroblasts, the two main components that make up the skin’s connective tissue. These coated the surface like a primer, forming a seamless layer for the next layer of cells – human epidermal keratinocytes – to adhere to. Wriggling the finger created natural-looking creases on the knuckles, and if injured, the artificial skin used a collagen bond to heal like humans and feels like normal skin, according to the scientists.
The finger is a work in progress: its skin is much weaker than natural skin and needs to be kept moist because without a circulatory system the cells would die as they dry out. His movements are also decidedly mechanical.
“The finger looks slightly sweaty right out of the culture medium,” Takeuchi said. “Since the finger is powered by an electric motor, it’s also interesting to hear the clicking sounds of the motor consistent with a real-looking finger.”
However, experts say it’s this combination of being very lifelike and mechanical that can trigger a sense of revulsion known as the “uncanny valley” effect.
dr Burcu Ürgen, from Bilkent University in Ankara, Turkey, said: “It’s possible that the human-like appearance [of some robots] evokes certain expectations, but when they don’t meet those expectations, they come across as spooky or spooky.”
Prof Fabian Grabenhorst, a neuroscientist at the University of Oxford who also studies the so-called uncanny valley effect, said: “It seems to be a fantastic technological innovation.”
He agreed that humans might initially react negatively to the mix of human and robotic traits, but research has shown that this reaction can change depending on how you interact with a robot. “In the beginning, people may find it weird, but through positive experiences that could help people overcome those feelings.”
The team now plans to incorporate more complex functional structures into the skin, such as sensory neurons, hair follicles, nails and sweat glands. They’re also working on a skin-covered robotic face. The progress is detailed in Matter magazine.