The finger, which has been shown to be able to heal itself, is considered an impressive technical achievement that blurs the line between living flesh and machine. But scientists were divided over whether people would be excited about his living anatomy or find it creepy. “We are amazed at how well the skin tissue adapts to the robot’s surface,” said Shoji Takeuchi, a professor at the University of Tokyo who led the work. “But this work is only the first step towards creating robots covered with living skin.” The team argues that more live humanoids could interact with humans more naturally in a range of roles, including nursing and the service industry. “I think living skin is the perfect solution to give robots the look and feel of living creatures, as it is exactly the same material that covers animal bodies,” said Takeuchi. He added that such developments had the potential to “build a new relationship between humans and robots”. The human appearance of the mechanical finger can cause a sense of disgust known as the “unusual valley” phenomenon, experts say. Photo: Shoji Takeuchi Scientists have previously produced skin grafts – skin sheets that can be sutured together in reconstructive surgery, for example – but have struggled to create living skin in three-dimensional, dynamic objects. In the last work, the team first immersed the robotic finger in a cylinder filled with a solution of collagen and human dermal fibroblasts, the two main components that make up the connective tissues of the skin. These coated the surface like a paint primer, providing a seamless layer to adhere to the next layer of cells – human epidermal keratinocytes. Bending the finger back and forth caused the natural appearance of wrinkles on the joints and when injured, the created skin could heal itself like humans with the help of a collagen bandage and, according to the scientists, feel like normal skin. The finger is a work in progress: its skin is much weaker than natural skin and must be kept moist as without a circulatory system cells would die if dried. His movements are also clearly mechanical. “The finger looks slightly sweaty straight from the culture medium,” Takeuchi said. “Since the finger is driven by an electric motor, it is also interesting to hear the clicking sounds of the motor in harmony with a finger that looks exactly like real.” However, experts say that this combination of very realistic and mechanical is what can cause a sense of disgust, known as the “unusual valley” phenomenon. Dr Burcu genrgen, of Bilkent University in Ankara, Turkey, said: “Human appearance is possible [of some robots] it raises certain expectations, but when they do not meet those expectations, they are considered eerie or creepy. “ “It looks like a fantastic technological innovation,” said Professor Fabian Grabenhorst, a neuroscientist at the University of Oxford who also studies the so-called strange valley phenomenon. He agreed that humans may have an initial negative reaction to the mixture of human and robot traits, but said research has shown that this response can change depending on the interactions with a robot. “At first people may find it strange, but through positive experiences that can help people overcome these feelings.” The team now plans to incorporate more sophisticated functional structures into the skin, such as sensory neurons, hair follicles, nails and sweat glands. They also work on a robotic face covered in skin. Progress is described in Matter magazine.
