The "Southampton Remedi-Hand" is a new, ultralight artificial hand that its developers claim can mimic the motion of a human hand better than any other existing technology. Developed by medical physicists at the University of Southampton, the prototype is outfitted with six sets of motors so each digit can move on its own. The wearer controls the device by flexing his or her arm muscles. From a press release:
They built the Remedi-Hand in three parts – the three middle fingers are very similar in size and movement so they made those identical. The pinky is a smaller version of the same. Each of these four fingers are made up of a motor attached to a gearbox attached to a carbon fibre finger. All of this is fitted to a carbon fibre palm. But the thumb was much more complicated and is the first artificially-made opposable thumb.
The human thumb can move in special ways the fingers can't. It can rotate as well as flex and also move in a variety of different directions. It can also oppose (touch) each of the fingers in the hand to form a 'pinch'. To mimic this, the Remedi-Hand uses two motors – one to allow it to rotate and one to allow it to flex. "The real thumb can move in five types of way, we've managed to create a thumb that can mimic at least two of these which is a really exciting achievement. It's a thumb that has really good flexibility and functionality" says (researcher Paul) Chappell.
One of the key differences between mechanical, artificial, limbs is that they arn't able to sense pressure or touch in the same way human limbs can. The next stage of Dr Chappell's research is to integrate the latest sensors technology with the Remedi-Hand to create a 'clever' hand which has better functionality and move like a real hand, but which can also sense how strongly it's gripping an object or whether an object is slipping.
