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The sense of touch of robots and prosthetic hands could be as fast as that of humans

Research from Uppsala University and the Karolinska Institute could pave the way for a prosthetic hand and a robot to be able to sense touch like a human hand. Their study has been published in the journal. Science. The technology could also be used to help restore lost functionality in patients after a stroke.

“Our system can determine what type of object it finds as quickly as a blindfolded person, simply by feeling it and deciding whether it is a tennis ball or an apple, for example,” says Zhibin Zhang, a professor in the Department of Electrical Engineering at the University from Uppsala.

He and his colleague Libo Chen conducted the study in close collaboration with researchers from the Signals and Systems Division at Uppsala University, who provided expertise in data processing and machine learning, and a group of researchers from the Department of Neurobiology, Neurosciences. Care and Society, Neurogeriatrics Division of the Karolinska Institute.

Inspired by neuroscience, they have developed an artificial touch system that mimics the way the human nervous system reacts to touch. The system uses electrical pulses that process dynamic tactile information in the same way as the human nervous system. “With this technology, a prosthetic hand would feel like part of the user’s body,” explains Zhang.

The artificial system has three main components: an electronic skin (e-skin) with sensors that can detect pressure by touch; a set of artificial neurons that convert analog touch signals into electrical pulses; and a processor that processes the signals and identifies the object. In principle, you can learn to identify an unlimited number of objects, but in their tests the researchers used 22 different objects to grasp and 16 different surfaces to touch.

“We are also studying the possibility of developing the system so that it can sense pain and heat. It should also be able to sense what material the hand is touching, for example whether it is wood or metal,” says assistant professor Libo Chen. , who led the study.

According to researchers, interactions between humans and robots or prosthetic hands can be safer and more natural thanks to tactile feedback. Prosthetics can also be given the ability to manipulate objects with the same dexterity as a human hand.

“Skin contains millions of receptors. Current e-skin technology cannot provide enough receptors, but this technology makes it possible, so we would like to produce artificial skin for a complete robot,” Chen says.

The technology could also be used medically, for example to monitor movement dysfunctions caused by Parkinson’s disease and Alzheimer’s disease, or to help patients regain lost functionality after a stroke.

“The technology can be further developed to know if a patient is about to fall. This information can then be used to stimulate a muscle externally to prevent the fall or prompt an assistive device to take control and prevent it,” he says. Zhang.