POWERWALK is a partial exoskeleton worn on the user’s leg. Exploiting what Industrial Designer Rob Nathan terms, “inefficiencies in gait,” the kinetic energy harvester delivers uninterrupted, potentially life-saving power for communication, navigation and optics. The 10-12W per hour produced in normal motion by a user wearing a harvester on each leg, “is enough to be able to completely charge a smartphone in 20-30 minutes,” Nathan explained.
The obvious advantage is in reducing the weight carried by the soldier in the form of batteries for the plethora of powered equipment today’s combat environment calls for. The weight burden of a US soldier on a 72 hour mission currently stands at 36lbs of batteries – including those already embedded in his equipment and an adequate level of redundant or spare units. “POWERWALK can easily replace those redundancies,” Nathan told Mönch.
Feedback from user trials has been positive and extremely useful, according to Nathan. Soldiers at the US Army Natick Soldier Center, for example, have evaluated the system and found there is a placebo effect – a sense of being empowered. The reality of course, is that POWERWALK does nothing to enhance capabilities in terms of strength – soldiers will not be able to leap tall buildings in a single bound or catch speeding bullets in their teeth. It will, however, make efficient use of expended energy and contribute to a better combat readiness through reduced fatigue. “There is a reduced metabolic cost of around 7% attributable to the removal of excess weight,” Nathan said.
Added benefits have been serendipitous as development continues. For example, since POWERWALK needs a connection between knee and ankle, the company decided to turn the connecting material into a shinguard. That has had unanticipated benefits for user acceptance: “Soldiers love the shinguard effect – especially in circumstances such as window entry,” Nathan told Mönch.
Multi-unit field tests will begin with US Army and USMC units in 2017 and the company currently estimates it will be ready for volume production by the end of 2018.