Army developing a power-generating backpack

A soldier tests the Energy Harvesting Backpack on a treadmill at ARL.

Army researchers are continuing apace with work that could one day lighten soldiers’ loads by letting them get the power they need without carrying extra batteries. Instead, they would generate power from their backpacks just by walking.

The prototype Energy Harvesting Backpack, being tested at the Army Research Laboratory, adds a two-spring frame to a standard assault pack that moves up and down when the wearer is walking or running, generating power from the motion that recharges a soldier’s battery, ARL said in a release.

The prototype, which is being tested at ARL’s Soldier Performance and Equipment Advanced Research (SPEAR) at Aberdeen Proving Ground, Md., also holds the pack in a controlled motion, as opposed to bouncing around when running like a typical backpack would, which could reduce fatigue while on a mission.

While testing the backpack’s power-generating ability, researchers also are using SPEAR’s equipment to study the effect of the weight on a soldier’s gait. Test subjects start with a regular assault pack, walking or running on a treadmill that can be adjusted to simulate uphill, downhill or level grades. n they do the same with the Energy Harvesting Backpack.

Sensors allow researchers to capture “ground reaction forces,” that is, the impact on the body of walking or running while carrying that weight, said Courtney Webster, an ARL biomedical engineer. Meanwhile, a dozen cameras overhead, each equipped with a near-infrared light and sensor, shine light onto the subject, who is wearing reflectors. The system collects 3D information on the subject’s position, velocity and acceleration, as well as biomechanical indicators of good or bad posture.

That, along with a device that measures oxygen intake, can help determine if a soldier’s gait could lead to injury or if the subject is becoming fatigued, ARL said.

To date, a dozen Army civilians and contractors, both male and female, have been tested on the backpack. ARL plans to publish its results after 20 people are tested. The backpack will be tested more widely once it gets past the preliminary research phase.

ARL will share its results with other military researchers, who have been working on wearable technology that can both generate power and help prevent injury. The Army’s Communications-Electronics Research, Development and Engineering Center worked with a company called Lightning Packs on designing the Energy Harvesting Backpack.

ARL also has worked with the Defense Advanced Research Projects Agency’s Warrior Web program, which is developing a soft exoskeleton that would help soldiers carry their loads, reducing the risk of fatigue and injury.