 Voluntary closing systems provide directly proportional control and biofeedback so that the user can feel how much force that they are applying.A recent study showed that by stimulating the median and ulnar nerves, according to the information provided by the artificial sensors from a hand prosthesis, physiologically appropriate (near-natural) sensory information could be provided to an amputee.This feedback enabled the participant to effectively modulate the grasping force of the prosthesis with no visual or auditory feedback.