without help. i was ecstatic. i had feelings of hope and a great sense of independence. the key to the technology is this tiny sensor dwarfed even by a five pence piece. it's implanted on the surface of the brain in an area known as the motor cortex. when the patient thinks about moving their arm, neurons in the brain are activated and these electrical signals are picked up by the sensor and sent to a computer which turns them into commands. and these are what those signals from the brain look like when directing the drink to the patient's lips. >> it was really a moment where we helped somebody do something that they had wished to do for many years. >> reporter: this tiny sensor was inserted into the arm of this robotics expert from reading a decade ago as part of an earlier trial. it enabled him to control a robotic claw. he says the technology could give independence to paralyzed patients. >> this will allow people to do things for themselves.