There are already a number of gadgets available that are powered through good old-fashioned mechanical energy, but those usually involve cranks that can be uncomfortable to use and bulky to carry around. Mipwr Dynamo represents a different approach: it's an iPhone case with a hidden lever that can be pressed down repeatedly to charge the battery, but is still slim enough to fit in your pocket.

The Mipwr Dynamo design team, founded by Karl Lee and Bob Panos, says the inspiration to build their human-powered phone charger came from seeing reports of people struggling to find power following Hurricane Sandy. It's these situations where electricity is especially scarce, like during a camping trip or a natural disaster, that the Mipwr Dynamo is primarily intended mainly.

A switch on the side of the case releases the small lever at a position where it can be gripped comfortably. Pushing this down spins a magnetic dynamo inside the case and charges a built-in 400 mAh battery through electromagnetic induction. One minute of squeezing the lever will equal about 30 seconds of talk time, according to the designers. When you're done charging, the lever can then be locked back into place.

Fortunately, you won't have to squeeze the case for four hours to completely charge it, since it also includes a port for a micro-USB connection that can recharge your phone and the Mipwr Dynamo simultaneously. When it is fully charged, the developers claim the Mipwr Dynamo's battery provides enough power for two hours of talking or texting.

At the moment, the developers only have working prototypes for the iPhone 4/4S but plan to use the funds from their current Kickstarter campaign to finalize a model for the iPhone 5/5s and begin mass production. They're attempting to raise US$78,000 for the project, and pledges for the Mipwr Dynamo begin at US$25. If all goes well, the company plans to ship the first batch of phone chargers in Feb. 2014.

In the meantime, you can watch the video below to see co-founder Karl Lee demonstrate how the Mipwr Dynamo works.

View gallery - 11 images