A 28-year-old quadriplegic is the first person to experience tactile sensation through a prosthetic hand, according to DARPA. The organisation accomplished this feat by routing signals from torque sensors housed in the mechanical prosthesis to electrode arrays attached to the volunteer’s sensory cortex—the part of the brain that identifies stimuli like touch.

"By wiring a sense of touch from a mechanical hand directly into the brain, this work shows the potential for seamless bio-technological restoration of near-natural function," said DARPA program manager Justin Sanchez in a press release.

The prosthesis used in the experiment was created by the Applied Physics Lab at John Hopkins University, and is capable of detecting when pressure is applied to a finger. DARPA reported nearly 100 percent accuracy in an initial set of tests. Despite being blindfolded, the volunteer, whose name is being withheld, was able to tell which extremity was being touched, and even when researchers were attempting to trick him.

"At one point, instead of pressing one finger, the team decided to press two without telling him,” Sanchez explained. “He responded in jest asking whether somebody was trying to play a trick on him. That is when we knew that the feelings he was perceiving through the robotic hand were near-natural."

Only basic findings were revealed during DARPA's Wait, What? A Future Technology Forum event last Thursday, with more details potentially to follow pending peer review and publication in an as-yet-unnamed scientific journal. This breakthrough, which originates from DARPA’s Biological Technology Lab, is relatively unique as it focuses on conveying the ability to “feel,” as opposed to the restoration of motion. The latter is a comparatively advanced field already: last year, DARPA poured $40 million (£26 million) into the development of an FDA-approved prosthetic arm. Then earlier this year, 34-year-old Erik Sorto drank beer with the help of a neural implant capable of reading the intention to move a robotic arm.