Finally, you can recharge your iPod with Clif bars. Letterio. In their basement shop full of mills and
When the military needed to recharge batteries on lathes, the two added springs to suspend the cargo the move, they turned to University of Pennsylvania compartment from the pack frame. As the wearer’s professor Larry Rome, an expert in muscle power stride raises and lowers the pack, the load slides up and, it turns out, a capable inventor. His solution: and down, driving vertical rods to spin a geared DC the world’s first electricity-generating backpack. servomotor up to 5,000 rpm to generate electricity.
Rome, who studies fish muscles, says the idea With a 40-80 pound load, Rome’s pack generates struck him in a Navy meeting. U.S. troops were 7 watts, plenty of juice to simultaneously power a lugging 80-pound packs, including 20 pounds of two-way radio, GPS receiver, and night vision gog-batteries for high-tech gadgets. The brass wanted gles (or cellphone, PDA, digital camera, and iPod). to use muscle power to generate electric power, but The load can be locked for stability on sketchy ter-the best existing technology was shoe generators, rain, and then unlocked to generate power again. straight out of Get Smart. Ultimately, the generator pack (patent pending)
“I said, ‘That’s a terrible idea,’” recalls Rome. will weigh just a couple pounds more than a regular “The force of the heel strike is only over a couple backpack. Carrying it burns 3% more energy, but millimeters. The right way became obvious: with wearers say it’s more comfortable, and the extra every step, these guys are lifting 80 pounds 5 to 7 work costs only a couple of extra candy bars. (“Food centimeters — that’s potentially 36 watts of is 100 times more efficient than batteries.”) Green mechanical energy.” bonus: the technology could keep tons of toxic
To turn his brainstorm into hardware, Rome batteries out of landfills. —Keith Hammond grabbed an old external-frame backpack from college days and called his lab’s “very fine machinist” Fred >>Lightning Packs: lightningpacks.com
Photograph courtesy of Larry Rome
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