Stay back, Pancho! Onward, Rocinante!!!
Is it plausible that "waving the phone in the air for a few minutes" with a bunch of micro-windmills could ever be more efficient than turning a crank for a few minutes?
And don't those crank chargers require some minutes of cranking for each minute of phone use?
I would think that micro-cantilevers that convert vibration into power would be more practical since they could be constantly generating power.
Using this to power nanoscale devices might be possible. But there is no way you would get enough power from a cell-phone-sized volume of these to power an actual cell phone.
So we'll not only have scratched screens to worry about, but tens of tiny fragile spinning mechanical windmills to worry about? Yeah, they'll last long.
...and as for the idea of putting them on the sides of buildings... how long do they really think they'll last against wind, rain, ice, snow, bird shit, moss, soot, etc etc etc.
It's an admirable idea, and awesome technology, but practically they aren't going to last long or work well in the situations described.
How would you be able to touch the surface of the device without scraping millions of nano-propellers off and into your skin?
Will someone think of the tiny birds?
Not only that, but since the power you can generate is proportional to the area of airflow you can intercept, using super tiny windmills on a building just doesn't make a whole lot of sense compared to installing full sized ones.
If you could hook it up to collect the wind coming out of a mouth speaking into a phone, my mother could power lower Manhattan.
I rather doubt they'll be all that useful at powering devices that spend most of their time in a pocket or purse.
I'd be really angry when the mini-props/windmills get stuck in my hair.
Depends which pocket. Just imagine if you could capture energy from all the wind that normally escapes through the back of your pants!
That's how they get you.
I wonder if UT Arlington still takes thermodynamics seriously?
Basically they want to pull the energy equivalent to a good workout by just waving the device a few times?
If with science this solid they get Dep of Energy founding, their next goal should be dieting and getting the young to exercise and avoid bloat.
Like, if just waving your arm a few times is equivalent to a good workout, then it can work in every sense, right?
Remember the One Laptop Per Child cranks? it turned out that when someone that understood energy better than most people understand vaporware took a look at it, it would have taken 3 hours at full power for an athlete to charge one laptop battery. That, for a device designed to be used by 9 year old kids that maybe often were also malnourished. No wonder the crank sort of disappeared except in ads, though OLPC never formally established it had been a bad idea all along.
Cannot trump science, but to avoid messing up, y'all got to accept evidence. Hard thing, that....
But there is no way you would get enough power from a cell-phone-sized volume of these to power a modern cell phone.
Well, you beat me to it. "Apple recommends to keep your iMill nano in your back pocket for optimal recharging".
There just isn't enough energy even with 100% efficiency conversion and assuming the entire surface of the cell phone was covered. Unless there are totally new physics invented, there is no way to generate the kind of power needed to power a device to communicate wirelessly for any distance and reasonable amount of time. I bet even combining all wind, thermal and kinetic energy, you STILL couldn't generate a significant amount.
Like Boris and others have mentioned, it takes real work to generate the power. Wireless devices aren't going to suddenly gain orders of magnitude better energy efficiency. There are some hard limits to broadcasting a signals through air. Plus newer technologies are focused on bandwidth than energy. "The average power consumption for a 10-minute CDMA circuit-switched call was 680 milliwatts" and VoLTE was DOUBLE that.