People power

While it may be worrying for those companies eyeing up big-ticket projects such as the Trident replacement, the current debate over whether defence spending should be refocused is welcome news for the modern soldier.

Drowning under the weight of an ever increasing payload of armour and power hungry electronics today’s infantryman is badly in need of some innovation, and growing calls for the development of technology to lighten this load will be well received.

The armour that makes up a significant percentage of the average soldier’s payload is the obvious target, but with batteries typically accounting for around 10kg, new methods of power storage or even power generation could also make a big difference

A couple of weeks ago in this column we touched on the military potential of a photovoltaic tent developed by Orange, but a couple of recent projects suggest that solar power might not be the only so called ambient energy source ripe for exploitation.

Researchers at Leeds University are among those looking at the development of so-called kinetic energy harvesting systems which use the body’s motion to generate electricity.

There are a number of possible ways of achieving this. One idea is to place piezoelectric materials, which generate a current when deformed, in the heel of a shoe. When the person wearing the shoe walks along the material is repeatedly deformed and a small charge is generated. Another approach, already used on some wristwatches, exploits movement to cause a magnet in an electromagnetic generator to move and induce a current. Elsewhere, using more traditional engineering techniques, Canadian firm Bionic Power has achieved promising results with its so-called Bionic Energy Harvester, a lightweight mechanical knee brace that is claimed to extract around seven watts of electricity from each leg, enough to operate 14 mobile phones.

While a number of kinetic energy harvesting systems are already on the market, the rigorous demands of the battlefield could push the technology way beyond its current niche as an iPod recharging gimmick.

Indeed, the greater power, improved reliability and ruggedness demanded by the battlefield may lead to systems that could power vital signs monitoring equipment in the equally demanding world of healthcare technology. Perhaps athletes and sportspeople - themselves major generators of kinetic energy - could also find applications for recovered energy.

For even more useful amounts of energy, kinetic energy recovery systems could even be installed in busy public places like stations and exploit the footfall of thousands of commuters to power lighting or information displays.

Jon Excell, Deputy Editor