Most soldiers carry a heavy burden in the field, including an 80-pound backpack filled with essential supplies and tools.
If that’s not heavy enough, soldiers often carry an additional 20 to 30 pounds in backup batteries to power their radios and other necessary electronics.
However, a new innovation offers a solution.
Lightning Pack—a 2017 R&D 100 Award Winner—is able to generate electricity as soldiers walk and run through the field, eliminating the need for them to carry batteries. They received the award at the R&D 100 Awards Gala held in Orlando, Florida on Nov. 17, 2017.
The backpack works by harvesting kinetic energy, while also reducing the heavy load soldiers have to carry around the field, said Lawrence Rome, PhD, the founder and chief scientific officer of Lightning Packs LLC, in an interview with R&D Magazine.
“Essentially in our backpacks there are two frames, there’s a frame connected to the person with a hip belt and shoulder straps and there is a second frame called a moving frame in which the bag is attached and the whole load sits there,” he said. “In normal backpacks, the two frames are locked together and move in unison.
“What we did is we suspended the moving frame from the fixed frame attached to the body by a spring mechanism,” he added. “So essentially as you walk up and down the moving frame moves in respect to the fixed frame and that generates electricity.”
By reducing the need for extra disposable batteries, soldiers using the backpack can opt to either reduce the overall weight of their backpacks or use the extra space to carry other necessary supplies. The packs also permits longer mission durations and reduces the demand for resupply operations.
In addition to providing a benefit for soldiers, the electricity-generating backpack could provide wearable, renewable electricity for disaster-relief workers operating in remote locations, as well as forestry service workers, medical aid relief workers, hikers, campers, and hunters.
The inspiration for Lightning Pack
Rome was a muscle physiologist in 2002 studying how fish swim when the U.S. Navy approached him unexpectedly on a possible project to develop a submarine that maneuvers similar to a fish.
During conversations with members of the military regarding the submarine, Rome learned about the heavy backpacks that many soldiers must regularly wear.
Although the task of designing a backpack was outside his expertise at the time, Rome was inspired to take on the challenge of eliminating some of the weight from the extra batteries using his knowledge of biomechanics.
“I know from teaching biomechanics that every step they take their hip goes up and down two-to-three inches,” Rome said. “So if their 80 pound backpack is connected at the hip then you have 80 pounds going up and down in every step. That winds up being a lot of mechanical energy.”
Benefits of Lightning Pack
According to Rome, prior to Lightning Pack’s creation the most electricity that was ever derived from walking was 20 milliwatts.
Lightning Packs can generate 12 to 15 watts of electricity by walking at a relaxed pace, 20 to 35 watts by walking at a hump pace, 33 to 40 watts by running and 30 to 50 watts by hand pumping.
Walking can also reduce the accelerative force by 82 percent and running reduces the accelerative force by 86 percent, allowing soldiers to have greater mobility in the field.
The electricity-generating backpacks currently come equipped in three sizes for a military assault pack, a mid-sized molle and a large molle ruck.
Rome explained how the extra electricity is ultimately used.
“Essentially what happens is the electricity that we generate goes to a few different places,” Rome said. “If you have a radio, it could power the radio directly. The excess electricity goes onto a battery, so the output plugs into a military battery.”
Rome said that radio communications are one of the largest drains of battery power for soldiers.
By having soldiers generate electricity by themselves, the military can reduce logistical support, dangerous supply routes and the over environmental impact due to having fewer disposable batteries.
Some of the other benefits include allowing soldiers to manage heavy loads with less stress on the body and minimizing acute and long-term musculoskeletal injuries, while also increasing force readiness and retention.
Lightning Packs are currently being developed with funding from the U.S. military and the National Institutes of Health. The military is currently undergoing stringent field tests on the backpacks.
The next step for Rome and the Lightning Pack team is to focus on creating a non-military version of the backpack that consumers can potentially use to power cell phones, GPS devices and other electronics.