Pounding Pavement Generates Electricity When Wearing Novel Backpack

[emad]

Pounding Pavement Generates Electricity When Wearing Novel Backpack



Scientists have developed a backpack that makes "power walking" a reality. Described today in the journal Science, the novel device translates the regular up and down movement of a walker's hips into electrical energy. The contraption could conceivably help provide power to soldiers, relief workers, scientists and others on remote trips.

When out for a stroll, a person's hips move up and down between five and seven centimeters during every step. Larry Rome of the University of Pennsylvania and his colleagues exploited this trait to design their new "suspended load" backpack. The bag is based around a frame, which is connected to a wearer's hips, and as the frame gets raised and lowered, the backpack's contents move up and down. This pogo stick-like motion generates mechanical energy, which in turn is converted into electricity by an attached motor. In laboratory tests, volunteers wearing backpacks that weighed between 20 to 38 kilograms generated about 7.4 watts of power, an amount that could simultaneously operate multiple small electronic devices. (Equipment bags of target users typically weigh more than 36 kilograms, the scientists say, with up to 25 percent of the load attributed to replacement batteries.) Because the amount of mechanical energy correlates to how much weight is moved, a heavier pack or a faster gait both translated into greater power generation.


The scientists note that the backpack's outer metal frame, which weighs under six kilograms, slightly altered how subjects walked, making their strides more efficient. "Metabolically speaking, we've found this to be much cheaper than we anticipated," Rome remarks. "The energy you exert could be offset by carrying an extra snack, which is nothing compared to the weight of extra batteries." The team hopes to refine the design, which is currently a prototype, and perhaps someday remove the need to lug replacement batteries on long treks. --Sarah Graham
http://www.sciam.com/article.cfm?chanID=sa003&articleID=000E2203-A303-1320-A30383414B7F00A7

[Ready4Change]

1. Very cool

Very nifty idea.

I can see incorporating coils like those used in those shake powered flashlights into the frame of a backpack. I also wonder if the generation of power from these coils might damp out the motion of the backpack, decreasing the effort needed to control the backpacks motion?

Could make hiking motions more effiecient, as well as saving weight otherwise used for batteries.

Great idea.

[emad]

2. Uness you are Asian Muslim living in UK and carrying a backpack

similar-looking to those circa 7 July and 21 July 2005...

[Ready4Change]

3. Well, barring unfortunate styling choices.

Maybe it could be done "Hello Kitty" style? After, what self respecting religious terrorist fanatic would be caught dead wearing a pink Hello Kitty backpack? (grin)

But yah, having a generator in the backpack might make getting through airport customs a real hassle.

[muriel_volestrangler]

4. Perhaps, but the best solution is to use the Nepalese method

as shown in the linked article: http://www.sciam.com/article.cfm?articleID=00090E37-07CC-12B2-87CC83414B7F0000

the head band ('namlo' to the Nepalese, the rare 'tumpline' to Canadians) is the most efficient way of carrying heavy loads. But we've ignored it in western backpack design.

Since the article says it's target users carry packs of about 36kg, and up to 25% of that is batteries, it's fairly clear they're talking about the military. Who else carries 20lbs of batteries with them? With LED headtorches, a few AA batteries last forever these days. I suppose civilians could do with a way of powering digital cameras.