Invention Awards 2014: Charge Gadgets With Your Footsteps

     Each thud of a hiker’s heel releases enough energy to illuminate a light bulb. Rather than waste that power, Matt Stanton, an engineer and avid backpacker, created a shoe insole that stores it as electricity. The device promises to be an improvement over traditional, hefty power packs as well as solar chargers, which work slowly or not at all, depending on the weather.

          Stanton worked closely with Hahna
Alexander, a fellow Carnegie Mellon University
engineering student, over three years to create
the SolePower system. Instead of using
piezoelectric and other inefficient, bulky
methods of generating electricity, the pair
shrunk down components similar to those
found in hand-cranked flashlights. The result
is a near standard–size removable insole that
weighs less than five ounces, including a
battery pack, and charges electronics via USB.
SolePower’s current version, to be released
later this year, requires a lengthy 15-mile walk
to charge a smartphone. But Stanton says the
company is working toward a design that can
charge an iPhone after less than five miles of
hiking and withstand about 100 million
footsteps of wear and tear.

How It Works:

1) A drivetrain converts the energy of heel

strikes into rotational energy, spinning

magnetic rotors.

2) The motion of the rotors induces an

electrical current within coils of wire.

3) Electricity travels along a wire and into a

lithium-ion polymer battery pack on a

wearer’s shoelaces.

Lead inventors:

Hahna Alexander,

Matt Stanton

Development cost

to date: $300,000

Company: Sole Power LLC