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New Twist on Power Walking
An anonymous reader writes "Carrying a newly designed backpack loaded with between 44 and 84 pounds of gear, users generate enough electricity to simultaneously power an MP3 player, a PDA, night vision goggles, a handheld GPS, a CMOS image decoder, a GSM terminal in talk mode, and Bluetooth."
Sounds a lot like the energy differential shown by hopping kangaroos. Their energy consumption is remarkably low given the velocities they generate and it seems to be the result of energy stored in their lower leg tendons. In other words they are using the same benefits to get a large increase in overall energy output with a marginal increase in metabolic consumption.
"The first thing to do when you find yourself in a hole is stop digging."
Maybe next they can reduce the need to carry water by recycling urine!
For most applications this is a nonstarter: if it's daytime, solar would work better (since it'd work at rests too) and for many operations at nigth, simply carrying a battery is easier, because you want say your nigth-vision goggles to keep working even if you leave the backpack behind for some job.
self-winding watches have been around for many years to store energy in springs to power a watch, and Seiko and other companies have watches which store electricy in ultra-capacitors.
why a backpack?
why not use wrist- or ankle-mounted generators, which get a lot more movement, so presumably the generator could be a lot smaller and lighter?
You may generate 7 watts but if you are storing that in a battery you won't get that much back out.
It's a good idea though since a suspended load is going to be absorbing energy anyway (ie. the springy-ness), might as well use that to generate power.
However, a lot more energy could be generated by absorbing the person's weight (plus anything they carry). For example, if you could store the energy absorbed by the padding of your shoes as you walked. Now that would be some power.
The ratio of people to cake is too big
Well, my mod points expired, so I'll have to just agree with you.
US Army's been developing computers for infantry for the last few years (I forget the code name, but it was typical Pentagon two parts macho two parts silly one part corny) and the stuff I read/saw said that the limiting factor was battery life. Rechargables are HEAVY. Tack that onto a 90kg pack that he's carrying anyway, and range gets shorter as your soldiers carry more If a grunt can power his laptop, field radio, GPS, and other electronics on the battlefield by walking and carrying the stuff he has to take anyway, and have that power generation help HIM to walk more efficiently, he can effectively power his gadgets for free AND get extended range by using less energy to walk/run. I can't see any way Defense ISN'T gonna be all over this like white on rice.
I've been somewhat involved in Geocaching, and one of the biggest complaints of cachers is running out of batteries for their GPS. One of the most popular trade items is spare AA batteries. If they can make this affordable to the consumer, and you can carry your water, trades, poncho, and whatever else you need for a day in the woods and power your Garmin or Magellan on the strength of that, that's huge.
Then there's the college kids with their newfangled eye-pods, high schoolers with cells, grade schoolers with game boys. They all carry a bunch of books everywhere they go. My high school backpack was 30-40lbs. That's a cell or PDA no prob. Retrofit a briefcase for Joe Yuppie to carry his paperwork and recharge his blackberry or laptop at the same time. Less time tied to an outlet, more time being on the road and productive (or so he'd have you believe). Get a small rig, put your mp3 player in it, strap it to your waist and go jogging. Kiss your low-battery warning goodbye. Make a tiny version and build it into a digital wristwatch, never change your battery again.
How are these people NOT going to be writing their own check?
Dare to Hope. Prepare to be Disappointed.
The guy carrying the pack is already raising it by a small amount with every step (because it bobs as he walks). Thus he is doing work. If the weight is suspended, it won't bounce as much with each step, and some of the energy previously used to lift the pack will go into the batteries. At least hopefully that's how it works out.