Amputee Dennis Aabo Sorensen from Denmark is the first person in the world to recognize texture (smoothness vs. roughness) using an artificial “bionic” fingertip surgically connected to nerves in his upper arm.
As a test, a machine controlled the movement of the fingertip over different pieces of plastic engraved with different patterns, smooth or rough, as sensors generated an electrical signal. This signal was translated into a series of electrical spikes, imitating the language of the nervous system, then delivered to the nerves. The scientists tested that by comparing brain-wave activity of amputees to non-amputees. The brain scans were similar.