Artificial fingers taught to recognize surface irregularities

Swiss engineers from the Federal Polytechnic School of Lausanne made a prosthesis that allows the brain to transmit information about the surface structure, and is able to distinguish a smooth surface from a rough one.

The volunteer Dennis Aabo Sørensen, who lost his left arm in an accident, helps engineers test the prosthesis. He has long been involved in testing innovative prostheses, and electrodes connected to the peripheral nervous system have been implanted in his inferior arm.

Having connected a finger to the electrodes, and having tried specially prepared plastic samples to the touch, Sorensen said that he could feel the difference in surface textures. In 96% of cases, he was able to correctly distinguish between smooth and rough surfaces.



In the prosthesis, the silicone “finger” is connected to a microcircuit equipped with sensors that convert surface information into a sequence of pulses that the subject’s brain can recognize.

It turned out that such sensations can be transmitted to people with whole limbs through temporarily introduced electrodes. The similarity of sensations obtained from the touch of a real finger and prosthesis was confirmed by measuring the brain EEG during the tests - the signals from the prosthesis activated the same areas of the brain as the signals from real fingers.

In previous experiments, Sorensen experienced a whole bionic hand, capable of conveying sensations about the shape of objects and their softness.