Japanese engineers are trying to get robots to mimic a uniquely human expression – a smile.
They created a mask from human skin cells and attached it to a robot using a novel technique that hides the bindings and is flexible enough to turn downward into a grimace or upward into a gentle smile.
The effect is somewhere between Hannibal Lecter’s scary mask and the claymation character Gumby.
But scientists say the prototypes pave the way for more complex robots with outer layers that are both stretchy and durable enough to protect the machines while making them look more human-like.
In addition to its expressive properties, the researchers say the “skin equivalent” made from living skin cells grown in a lab can also shed scars and burns and repair itself. A study published on June 25 Published in the journal Cell Reports Physical Science.
“Human-like faces and expressions can improve communication and empathy in human-robot interactions, enabling robots to play a greater role in healthcare, service, and companionship roles,” said Shoji Takeuchi, a professor at the University of Tokyo and the study’s lead researcher, in an email.
The research comes as robots are becoming more common on factory floors.
have 3.9 million industrial robots According to the International Federation of Robotics, by 2022, robots will be working on automotive and electronics assembly lines, among other work environments.
The total number of robots includes so-called humanoids, machines equipped with two arms and two legs that allow them to work in environments built for human workers, such as factories, but can also work in hospitality, healthcare and education.
Carsten Heer, a spokesman for the federation, said humanoid robots were “an exciting area of development” but mass market adoption would be complex and could be limited by cost.
Nevertheless, the Chinese government announced in October 2023 Mass production of humanoid robots By 2025, China is expected to have significantly increased its industrial productivity.
Over the past few decades, Robotics engineers have tried various materialsThe hope was to find something that would protect the robot’s complex mechanics while also being soft and light enough for widespread use.
The researchers said in the paper that if dents or scratches appear on the robot’s surface, it will cause the machine to malfunction, so the ability to self-heal becomes a “key feature” for humanoid robots.
Kevin Lynch, director of Northwestern’s Center for Robotics and Biosystems, said the novel skin attachment method advances the emerging field of “biohybrid” robotics, which blends mechanical engineering with genetic and tissue engineering.
Professor Lynch said: “This research makes an innovative contribution to solving the problem of fixation between artificial skin and underlying materials”, adding that “living skin may help us achieve the goal of self-healing skin for biohybrid robots.”
He added that the study did not address how the robotic skin would repair itself without external support.
For robots like these, the materials challenge extends to realism—finding ways to give machines features that make them look and act more like humans, such as the ability to smile.
Scientists including Professor Takeuchi and colleagues at the University of Tokyo have been studying lab-created human skin for several years.
In 2022, the research team Developed a robotic finger Covered with living skin, the machine’s fingers are able to bend like human fingers, giving it a sense of touch and allowing it to perform more precise tasks.
Professor Takeuchi’s team had tried using micro hooks to hold the skin in place, but these caused the skin to tear when the robot moved, so the team decided to mimic ligaments, the thin, loose tissues that connect bones.
The team drilled small V-shaped holes in the robot and applied a gel containing collagen to plug the holes and secure the artificial skin to the robot.
“This approach combines traditional rigid robots with soft biological skin to make them more ‘human-like,'” said Yifan Wang, assistant professor at the School of Mechanical and Aerospace Engineering at Nanyang Technological University in Singapore. His research area is “soft robotics” that mimic biological organisms.
Skin incorporation also gives biohybrid robots the potential to feel, bringing science closer to science fiction fantasy.
“This could create opportunities for robots to sense humans and interact with them safely,” Professor Wang said.
The robot in Professor Takeuchi’s laboratory is equipped with artificial skin, but its face cannot sense external stimuli such as touch and temperature changes.
Professor Takeuchi said this is his next research goal.
“Our goal is to create skin that functions very similarly to real skin by gradually building basic components such as blood vessels, nerves, sweat glands, sebaceous glands and hair follicles,” he said.
The robot’s electronics need to power sensor signals to replace the nervous system that transmits human sensations. Professor Wang said this development requires more time and research.
