Features
Photo of PowerWalk, an energy-harvesting bionic power knee device.
The bionic power knee harvester, also known as the PowerWalk, is an energy-harvesting device. The device may reduce the number of batteries a warfighter needs to carry, potentially lightening the load and freeing up space in backpacks for other supplies, including food and water.

The bionic power knee harvester, also known as the PowerWalk, is an energy-harvesting device that is attached to both the upper and lower areas of both legs and generates power from movement. The device extracts the energy when the knee is flexed and negative work is being performed. The system adjusts to a person’s gait, so soldiers don’t feel like they are wearing a device and can even forget that they have it on.

Soldiers now carry multiple electronics that aid in strategy, communication and navigation, including computers, radios, mobile phones, battlefield situational displays and navigation tools , justto name just a few devices. Being without power to run these devices could impact Soldier safety, performance and efficiency.

“The power generated by the device charges the main battery,” said Noel Soto, a project engineer at the U.S. Army Natick Soldier Research, Development and Engineering Center (NSRDEC). “The goal is to reduce the amount of batteries used by soldiers or to be able to extend the mission with the same load. We have found out through studies that soldiers are carrying a heavy load and a lot of that weight, 16 to 20 pounds for a 72-hour mission, is due to batteries.”

Heavy loads can increase injuries as well as impact mobility. In addition to potentially lightening the load by reducing the number of batteries needed, the energy-harvesting technology could also free up space in backpacks for other supplies, including food and water. “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,” Soto said.

NSRDEC is working with Bionic Power Inc. of Canada on the joint-service project, which will benefit the Army and the Marine Corps infantry. Project Manager Soldier Warrior, with the addition of the Office of the Secretary of Defense and USMC, lead the contract.

The knee energy-harvesting device also reduces muscle fatigue during downhill walking. “As a generator, it creates power,” said Soto. “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.”

Source