News | Dec 17, 2019

Army invention provides power one step at a time

Military R&D available for productization

News Article Image of Army invention provides power one step at a time

Illustration of the Army's newly issued U.S. Patent 10,499,703, "Shoe Insole and Generator."

Soldiers may soon be able to charge batteries with their footsteps, thanks to a new U.S. Army invention.

Nathan Sharpes, a mechanical engineer with the Army’s C5ISR Center in Maryland, has recently developed a shoe insole that can generate energy with every step, helping to power electronic devices.

The Army was issued U.S Patent 10,499,703 for Sharpes’ work on December 10th, creating a licensing opportunity for U.S. businesses who would develop it into new products or services for military or non-military customers.

The patent document describes an insole that uses the force of the foot strikes to drive a miniature rotational lever mechanism that turns a tiny generator, creating an electric charge.

“We embedded an energy-harvesting mechanism into a combat boot heel insole so that each time a soldier’s heel strikes it activates a generator, which spins to produce energy, Sharpes said.

“We improved the mechanism by making each step feel more natural versus the slight sinking motion soldiers experienced when using our previous version. We also sped up the generator’s timing mechanism to produce energy for longer than the previous version, which is a positive direction to achieve harvester efficiency.”

With the new-and-improved design, Army engineers produced a user-friendly product that works with the body to offset the counter-torque produced by rotational mechanism, making for a more comfortable step, Sharpes added.

Devices like Sharpes’ could help soldiers achieve energy independence, requiring fewer batteries and therefore lighter loads all while taking advantage of kinetic energy to power wearable technology and electronics such as radios.

Julie Douglas, another engineer at the C5ISR Center, has invented a backpack that can also convert kinetic energy into usable electrical energy.

Business Opportunity

With the increase in popularity of wearable fitness tech, the insole could also find a home in commercial markets, helping users power smartwatches, phones or other devices while walking or running.

TechLink, the Army’s partnership intermediary for technology transfer, is helping innovative companies identify the opportunity for commercializing the invention.

Brian Metzger, senior technology manager at TechLink, called the insole invention a “potential game-changer” for both military and commercial markets.

“The simplicity and flexibility of the insole mean that there are many ways that a company could adapt it,” Metzger said. “From cutting down weight for soldiers and increasing their power sustainability, to all the possible commercial uses for a product like this, the insole is an incredible marriage of design and execution.”

To learn more about how your businesses can leverage Army R&D contact, Brian Metzger, at or 406-994-7782.