Artificial fingers have been taught to recognize surface irregularities.

Swiss engineers from the Federal Polytechnic School of Lausanne have made a prosthesis that allows information about the surface structure to be transmitted to the brain 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 the engineers in testing the prosthesis. He has long been involved in the testing of innovative prostheses, and electrodes associated with the peripheral nervous system are implanted in his defective hand.
')
By connecting a finger to the electrodes, and trying to touch the specially prepared plastic samples, Sorensen said that he could feel the difference in surface textures. In 96% of cases, he managed to correctly distinguish 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 is able to recognize.

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

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