Unlike the artificial skin commonly used when building robots, this skin is alive, said study lead author Shoji Takeuchi, a professor on the project in the Department of Mechanical and Biofunctional Systems at the Institute of Industrial Sciences. from the University of Tokyo.
“Living Skin is the ultimate solution to making robots look and feel like living creatures,” Takeuchi said.
His research team chose a robotic finger for the experiment because this mechanism is well studied and is an essential part of a robot, he said.
Build the skin
Human skin is made from the same building blocks as human skin, Takeuchi said.
The robotic finger was first immersed in a solution of collagen, which is a fibrous protein, and human dermal fibroblasts, the two main components of human skin. Dermal fibroblasts are the main type of connective tissue cell in the skin.
Once the solution was shaped around the finger, Takeuchi applied human epidermal keratinocytes to the outside. A keratinocyte is the main type of cell that makes up the human epidermis, the outermost layer of skin, he said.
In the tests, the elastic human skin moved freely as the finger performed different movements, Takeuchi said. His team put a collagen bandage on part of the injured finger to repair it, and the robot was able to move freely after the protein repaired the skin.
Collagen is a major component of human skin and has healing properties, according to a 2021 study.
The skin could also repel water, which expanded the tasks the robot could perform.
When the researchers used a robot with a wet surface material, polystyrene foam beads stuck to it, according to the study. These beads are commonly used as filler material in products such as beanbags and some stuffed animals.
When the scientists tried the same experiment with water-repellent human skin, the robotic finger was able to push the foam balls away without them sticking, the authors said.
Design robots in our image
According to the study, humanoids are robots that perform tasks that involve interaction with humans in settings such as the medical, nursing and service industries.
It’s important to have robots that look like humans when they’re in places frequently frequented by humans, said Pulkit Agrawal, Steven and Renee Finn Career Development Professor and assistant professor in the Department of Electrical and Engineering. computing at the Massachusetts Institute of Technology in Cambridge. He did not participate in the study.
“Humans design spaces around themselves, so having a human-like robot is helpful in those scenarios,” Agrawal said.
For example, robots that might one day be in a household need to be able to pick up objects and move around like a person does, he said.
If a robot were to be made of metal, it would have to be extremely accurate in picking up another hard object like a cup, Agrawal said. There would be a small amount of contact between the two objects since neither is flexible.
If the hand was soft like human skin, the robot might be less precise because more surface area of the cup would be covered because the soft skin conforms to the handle, he said.
A step in the right direction
The discovery is important, Agrawal said, but the development of human skin still has a long way to go.
Skin is a living organism, so it needs to sustain itself by being constantly nourished while removing waste, Takeuchi said.
Unfortunately, the current skin that has been grown does not have this built-in ability, so it cannot sustain itself, he said.
Takeuchi wants to add a vascular system, the way blood circulates throughout our bodies, to help transport nutrients to and from cells and keep skin alive. He also wants to develop additional details for the skin such as hair follicles, nails and sweat glands.