Mechanics give a helping hand
Dr Paul Chappell, a medical physicist from the University of Southampton has designed a prototype hand that uses six sets of motors and gears so that each of the five fingers can move independently. This enables it to make movements and grip objects in the same way a real human hand does.
The new hand, called the “Southampton Remedi-Hand”, can be connected to muscles in the arm via a small processing unit and is controlled by small contractions of the muscles which move the wrist.
"With this hand you can clutch objects such as a ball, you can move the thumb out to one side and grip objects with the index finger in the way you do when opening a lock with a key, and you can wrap your fingers around an object in what we call the power grip – like the one you use when you hold a hammer or a microphone," Chappell said. The new hand the scientists have developed is only 400g.
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 next stage of 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.
Chappell and colleagues have already designed this 'clever' hand and are about to start building a fully functioning prototype. It will have piezo-electric sensors in each of the five fingertips which will detect how much force is being exerted on the tip and translate this information into an electrical signal which will be fed to a small processor.
COMPAMED.de; Source: Institute of Physics