Lessons From a Toad: How to Lighten Your Load

ByABC News
January 10, 2007, 7:15 PM

Jan. 11, 2006 — -- He never expected to become an inventor, but Larry Rome has created a backpack for the 21st century that could take a huge load off your shoulders. Or it could charge your cell phone and all those other dandy gizmos that we have to have today.

And it's all because he wanted to know how the lazy toad fish could suddenly lunge forward and grab a tasty morsel that just happened to be passing by.

If that sounds confusing, it's one of the reasons Rome feels these days as if he's stumbled into a "Lethal Weapon" movie. Even his colleagues sometimes wonder what he's up to.

"It seemed like a good idea at the time," he says. And it was.

Rome has invented two different types of backpacks. One runs a tiny generator, fueled by the mechanical energy produced by the movement of the wearer. The other reduces the force of a backpack's load on the wearer by a whopping 82 to 86 percent.

"It's like carrying an extra 12 pounds for free," says Rome, a professor of biology at the University of Pennsylvania.

Rome's ergonomic backpack uses common bungee cords to suspend the load at a constant distance from the ground, thus virtually eliminating the costly ups and downs that result from simply walking forward.

The research that led to his invention was funded by the Office of Naval Research and the National Institutes of Health, both of which hope to see the backpacks produced commercially for use by everyone from firemen rushing to a disaster site to young children who wear backpacks to school that are so heavy they could cripple a kid for life.

But for now, you can't buy one of his backpacks. He hasn't even thought about such consumer-oriented necessities as color and style.

So how does a biologist get into a project like this? For that, we have to go back to the fish.

For years Rome has studied muscles, trying to figure out which types of muscles do which types of activities. Humans have three types of muscle fibers, but it's hard to determine the precise properties of each type because even under a microscope, they're just so close that they blend together.