Research at Sweden’s Uppsala University and Karolinska Institutet could be another step toward allowing a prosthetic hand to feel touch like a human hand. Drawing inspiration from neuroscience, a team of researchers developed an artificial tactile system that imitates 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.
“Our system can determine what type of object it encounters as fast as a blindfolded person, just by feeling it and deciding whether it is a tennis ball or an apple, for example,” said Zhibin Zhang, PhD, docent at the Department of Electrical Engineering at Uppsala University.
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 analogue touch signals into electrical pulses; and a processor that processes the signals and identifies the object. In principle, it can learn to identify an unlimited number of objects, but in their tests the researchers have used 22 different objects for grasping and 16 different surfaces for touching.
“We’re also looking into developing the system so it can feel pain and heat as well. It should also be able to feel what material the hand is touching, for example, whether it is wood or metal,” said Libo Chen, PhD, an assistant professor at Uppsala University who led the study.
“The skin contains millions of receptors. Current e-skin technology cannot deliver enough receptors, but this technology makes it possible, so we would like to produce artificial skin for a whole robot,” said Chen.
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 recover lost functionality after a stroke.
“The technology can be further developed to tell if a patient is about to fall. This information can be then used to either stimulate a muscle externally to prevent the fall or prompt an assistive device to take over and prevent it,” said Zhang.
Editor’s note: This story was adapted from materials provided by Uppsala University.
The study, “Spike timing–based coding in neuromimetic tactile system enables dynamic object classification,” was published in Science.
