A monkey fitted with a hi-tech brain chip has learned to move a complex robotic arm using mind control.
The chip implant allows the monkey to manipulate the arm by thought
The animal can operate the robot with such dexterity that it can reach out to grab, and turn a handle.
The mechanical arm has an arm, elbow, wrist and simple hand, which the monkey controls with the power of thought.
Sky News was given exclusive access to the laboratory at Pittsburgh University in the United States.
The research is progressing so rapidly that scientists hope to start trials on paralysed patients within a year.
Neurobiologist Dr Andy Schwartz said: "What we're trying to do is go to a very dextrous hand - where the functionality is very similar to the human hand. If we could help stroke patients there would be a huge market for this kind of device."
They also hope to help patients who have been paralysed by spinal chord injuries or degenerative diseases of the nervous system.
Electrodes implanted in the monkey's motor cortex, the brain's movement control centre, pick up pulses within individual neurones.
The signals are relayed to a computer which analyses their pattern and strength to gauge what the monkey is trying to do. It then translates the signals to alter the speed and direction of the robotic arm.
The system is so quick that if the arm overshoots the monkey's intended target, it can rapidly correct the movement.
Dr Schwartz told Sky News: "It's pretty amazing because monkeys aren't used to moving tools.
Monkeys known for their intelligence
"We use them all the time. Imagine you're moving your arm to get that piece of food. Conveying that to a monkey is pretty difficult, yet the monkey learns it fairly rapidly.
"As the days go by, you see the monkeys start using it as if it is part of their own body."
The monkey cannot feel the electrodes in its brain, and did not appear to be distressed by the wires leading from a socket on its head.
At Brown University in New England, scientists have just started the first clinical trials of a similar device. Braingate allows tetraplegic patients to control a computer cursor by thinking about moving their paralysed hand.
Matthew Nagel took part in the first tests of a prototype. Before he died of an unrelated infection, he described how the Braingate device gave him back some freedom.
"I can't put it into words. I just use my brain. I said: 'cursor go up to the top right' and it did. And now I can control it all over the screen. It's wild," he said.
The new trial will be on 15 patients. Scientists hope to prove that the technology is safe and effective enough to use on a wider scale.
Head of the research, Professor John Donoghue, said the ultimate aim is for patients to regain control of their own limbs, which are more sophisticated than any robotic arm.
He told Sky News: "Our goal with Braingate is to have a physical replacement for a broken biological nervous system.
"So we'd like to have a physical system that senses what's going on in the brain, takes those signals inside your body and routes them off to the muscles, so when you think, you move.
"That's just what you or I do, so one day you could be sitting here with a person and you wouldn't know if they had the system or not.