August 22, 2005. Copyright 2005, Graphic News. All rights reserved

The strong suit that turns science fiction into reality
By Mark Rutter

LONDON, August 22, Graphic News:  Humans bestowed with supernatural strength, able to lift enormous weights and bound huge distances in a single leap -- the plot of another science fiction story? Not any more, thanks to recent advances in the design of suits providing the wearer with an ÒexoskeletonÓ, giving added strength and support to the joints and muscles. By bringing together mechanics and electronics, and applying it to robotic movement in the new field of cybernics, scientists are also offering hope of improved mobility to millions of disabled and elderly people.

Much of the development in this field has been carried out at the University of Tsukuba in Japan, where researchers are concentrating their efforts on a Òhybrid assistive limbÓ, or HAL. When strapped to the arms and legs, a series of battery-powered motors provide the limbs with extra strength. Sensors attached to the skin pick up electrical nerve impulses sent from the brain to the muscles, and send these signals to a small computer attached to the belt of the suit. The computer then controls motors at the joints of the exoskeleton to bring about movement. WhatÕs more, the researchers say that the speed of activating the motors is marginally quicker than for muscle movement alone.

Balanced and coordinated movement, required for example when walking or running, is also controlled through the computer. This is optimised for the individual so that any specific weaknesses are compensated for. As this information can be stored in the computer, this procedure needs only to be carried out once. Although the latest prototype, HAL 5, is still relatively heavy at 17 kilograms, the integral motors take the weight when moving, so the wearer is not aware of the full weight of the suit.

In the U.S., progress in exoskeleton technology to assist limb movement is being driven by military interests. For several years funding has been available for projects aimed at increasing the physical capabilities of soldiers. Up until now, the programme has been broad and designed to find the most promising technologies that might improve the fighting capability of troops. You can imagine the advantage gained by a soldier going into battle with superior speed, strength and endurance.

However, the specification for military use is more exacting. Its operation would need to be silent, and the power supply required to last for long periods. One promising technology is a pair of combat boots attached to metal braces strapped to the legs, which assist leg strength and work in a similar way to the HAL system. Another more fanciful idea is an exoskeleton that enables flying, complete with vertical take-off.

Research in the U.S. is still at an early stage, and, given the militaryÕs involvement, much of it is shrouded by secrecy. On the hand, HAL is likely to be available in Japan around the end of 2005 at a price up to 2 million yen, approximately $19,000. Its developers believe that the increasing elderly population of the world will provide a ready commercial market for the invention.
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