US Army to field test PowerWalk

The US Army is set to start field trials of the PowerWalk bionic energy-harvesting device in 2017, it announced on 26 October.

PowerWalk is an energy harvesting device designed to be worn on a soldier's upper and lower legs. It generates power from movement, extracting the energy expended when the knee is flexed and negative work is being performed. As it adjusts to a person's gait, soldiers don't feel like they are wearing a device.

The device - in development as part of the Joint Infantry Company Prototype programme, which in turn came out of the Soldier Power Generation programme - is being developed as an original concept for energy harvesting. The US Army Natick Soldier Research, Development and Engineering Center (NSRDEC) is working with Bionic Power of Canada on the joint-service project, which aims to benefit the army and the marine corps infantry. 

With soldiers now requiring multiple electronic devices for communication and navigation, soldiers are carrying every more weight in batteries to power these devices – as much as 16 to 20lbs for a 72-hour mission.

PowerWalk is designed to generate power to power these devices, in order to reduce the number of batteries needed to be carried by soldiers, and freeing up space in backpacks for other supplies, including food and water.

Noel Soto, a project engineer at NSRDEC, said: ‘The objective is to have the device weigh one pound and be capable of generating 3.5 watts and to have a device weighing two pounds able to generate 10 watts. 

‘In remote places, it could potentially increase self-sustainability and independence by reducing the need for resupply.’

The knee energy-harvesting device also reduces muscle fatigue during downhill walking. 

‘As a generator, it creates power', Soto said. ‘As a motor, it could enhance movement. It could potentially be used in the future for human augmentation. It acts as a brake when you are walking downhill. It actually helps soldiers by preventing sudden movement on the slope.’