Now, active artificial hand with muscles made from smart shape-memory wires

Researchers have recently developed an artificial hand that was able to respond sensitively because of the muscles made from smart shape-memory metal wires.

The new technology by engineers at Saarland University enables the fabrication of flexible and lightweight robot hands for industrial applications and novel prosthetic devices.

The muscle fibres are composed of bundles of ultrafine nickel-titanium alloy wires that are able to tense and flex. The material itself has sensory properties allowing the artificial hand to perform extremely precise movements.

The engineers used "smart" wires to play the role of muscles in the artificial hand. Multiple strands of shape-memory wire connect the finger joints and act as flexor muscles on the front-side of the finger and as extensor muscles on the rear. In order to facilitate rapid movements, the engineers copied the structure of natural human muscles by grouping the very fine wires into bundles to mimic muscle fibres.

Another effect of using the shape-memory metal wires was that the hand could respond in a natural manner when someone intervenes while a particular movement was being carried out.

A semiconductor chip controls the relative motions of the SMA wires allowing precise movements to be carried out. And the system does not need sensors.