The Electronics and Computer Science Department of the UK’s Southampton University has chosen Vesconite Hilube for various parts of an innovative low-weight sensor-rich prosthetic hand.
The polymer’s lower density (compared to alloys) was an important influencing factor in the decision to use it.
“A main constraint in the design of a replacement hand is that its mass should be kept as low as possible,” says primary investigator Paul Chappell.
As a result, the Southampton-Remedi hand uses carbon fibre sheet and Vesconite Hilube, with metals only used on the actuators of the electric drives.
Not only does the University’s research programme use Vesconite Hilube for the thumb of the hand, it’s been the material of choice for the ends of the worm and wheel shafts at the base of the fingers and thumb.
Vesconite Hilube’s self-lubricating properties mean that the gearbox does not require additional bearings at the end of the shafts, explains Chappell.
The Southampton-Remedi hand has four motors that move the fingers and two that allow for flexion (movement towards the palm), and extension (movement away from the palm), as well as rotation of the thumb.
The hand can grip and grasp objects securely, and the current prototype incorporates touch, position, slip, texture and temperature sensors.
Explaining the origins of prosthetic hands, Chappel says, “War often resulted in loss of hands, and this trauma led to the development of artificial replacements.”
“In the sixteenth century, Götz Von Berlichingen, a German warrior, and Ambriose Paré, a French surgeon, made hands from metal components.”
Various developments followed, including the split hook – a device that attached to the shoulders with leather straps and used the shoulder muscles to open the hand against a spring.
World War I and World War II, and subsequent conflicts, saw the rapid advance in these designs.
Southampton University has been at the forefront of some significant work on artificial limbs, and is also well known for the Southampton Hand Assessment Procedure, which assesses hand function.
Vesconite is proud to be part of this valuable research endeavour.