Kau found – perhaps not surprisingly – that prosthetics really work as assistants to the functioning limb. The resulting design is flexible and adjustable, providing a grip that changes to accomodate the object. The amount of curl in the arm is controlled by two buttons mounted on the prosthesis, which direct a single motor to either increase or decrease curl via two cables running the length of the arm.
...it doesn’t plug into the nervous system or recreate the missing five-fingered hand synthetically. But it’s not trying to. What it does, at least in concept, is offer a feasible, immediate solution to problems faced by those missing a partial limb. And it does so without great complexity or expense.