The researchers have revealed that the monkey involved in the study was able to operate the robot with such dexterity that it could reach out to grab, and turn, a handle.
According to them, the mechanical organ the monkey was taught to move using the power of thought had an arm, elbow, wrist, and simple hand.
The research team are so excited about the results of their latest animal study that they hope to start trials on paralysed patients within a year.
"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," Sky News quoted meurobiologist Dr. Andy Schwartz as saying.
The researchers also hope that their work may provide them with a strategy to help patients who have been paralysed by spinal chord injuries or degenerative diseases of the nervous system.
They have revealed that the electrodes they implanted in the monkey's motor cortex, the brain's movement control centre, picked up pulses within individual neurones.
The signals were relayed to a computer that analysed their pattern and strength to gauge what the monkey was trying to do, and then translated them to alter the speed and direction of the robotic arm.
The researchers say that their system worked so quickly that whenever the arm overshot the monkey's intended target, it would rapidly correct the movement.
"It's pretty amazing because monkeys aren't used to moving tools," Dr. Schwartz said.
"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," he added.
As an interesting finding, the research group observed that the monkey did not feel the electrodes in its brain, or appear to be distressed by the wires leading from a socket on its head.