The Mini-Generator Tzeno Galchev, University of Michigan

Finding large-scale sources of kinetic energy to turn turbines isn't easy. But while there are only so many roaring rivers and flat, windy plains from which to harvest nature's natural motions, there's no shortage of tiny, random vibrations all around us. Now researchers at the University of Michigan have developed mini-generators that harness these.

Miniature kinetic generators aren't new; for instance, many wristwatches are powered by energy gathered from the rhythmic swinging of our arms when we walk. Some piezoelectric generators have even been integrated into fabrics, meaning that your jacket could someday top off your cell phone battery or iPod, provided you move around enough.

But many of these approaches require pronounced movements to harness any real degree of energy. The new Parametric Frequency Increased Generators from the U of M team have a huge advantage over other kinetic energy harvesters because they can scavenge the arbitrary, ambient, non-repeatable vibrations that are far more common in the world around us.

For instance, the vibrations caused by traffic passing over a bridge could power wireless structural sensors on the underside of the structure, and everything from lampposts to skyscrapers could harness energy from wind vibrations to power -- at least partially -- their day-to-day operations. Placed in stairwells, the generators could harness the kinetic energy of climbing to power the emergency lighting, and on electric cars they could feed some of the energy lost through engine rattle back into the energy loop. They could even be used to power sensors in far flung, off-the-grid locales, like fire-detecting sensors deep within forests.

The human body is also a great potential energy source for these kinds of micro-generators. Typical amplitudes found on the human body can produce 500 microwatts, enough to run dozens of wristwatches or ten pacemakers, opening the door to better, more energy intensive medical devices that don't require periodic surgical battery swaps. Which, as anyone with a pacemaker will tell you, is a good thing.

Of course, the technology has a ways to go before it is deployed -- there are only three prototypes in existence right now, with a fourth on the way. But the future of self-sustaining little electronic monitors looks quite busy as we rely more and more on sensor driven data to monitor everything from our infrastructure to our bodies. Being able to unplug from the grid/battery paradigm and harvest energy locally is a big part of that equation.

[PhysOrg]

16 Comments

ive had an idea about electricity from sound waves vibration

i guess this very neatly fits the description.

when you can't sleep, some weird things come to your mind...
and so, it came to me. is it possible to create such material that will change magnetic state by it self, with no other influence around it? than, you place this "fantasy" material inside of the wire coil and you have "free" energy...

st.srki

when you can't sleep, some weird things come to your mind...
and so, it came to me. is it possible to create a flux capacitor? than, you place this "fantasy" object inside a DeLorean and you have a way to travel in time...

Come on, I think of stuff when I am falling asleep too but I don't post in online.

Let's keep perspective: this is a replacement technology for... 9v, AA and AAA batteries. Not hydrodams.

Wow, this is truly amazing.

Lou
www.privacy-online.eu.tc

The uses for this could be endless. Our roads and bridges could be lighted by the passing cars, perhaps waling on the floors of our homes could power led lights. Maybe we could power or at least partially power self-sustaining robotics.

1robotcompanion.com

If you attached this to a device that vibrates, would you have a perpetual energy machine?

If you attached this to a device that vibrates, would you have a perpetual energy machine?

Ahh I cold use one of these in my video game controller. Much better than having to plug the cord in to recharge, that my cat seems to like to attack every time it is strectched across the room.

extremechiton, by any chance, are you talking about a microphone?

@Dontcallmechief. i think you've solved the worlds energy crisis. You've discovered perpetual motion.

If this device can be made small and numerous enough, perhaps by being slit into a comb, it should be able to draw electrical energy straight from the Brownian Motion in liquids, thus defeating the Second Law of Thermodynamics. In a closed system, you'd have Perpetual Motion, or a steady supply of current from normal ambient temperatures.

Bob Stuart

@bobstuart

sigh.
bobbobbob...
this would not defeat the 2nd law. It would not create perpetual motion. The point of these devices is to get to the point that you describe - where even Brownian motion can be an energy source for human-designed systems.

However you appear to forget (or not know) the same part of the 2nd law that all the creationists forget (or don't know): The second law applies to *closed systems*.

You can use this device to gain energy & collect it in a battery for later use in a human endeavor, but it doesn't collect energy from *itself* - it collects energy from fluids (not liquids) outside itself.

these fluids would still not provide the endless energy you seek, however. If they are isolated (closed) systems of relating molecules. Brownian motion is a function of temperature. It can proceed for such long times in part because the collisions between atoms are fantastically elastic. But it is not eternal, and temperature is just a measure of average energy at the macro scale. If this device harvests energy from the collisions, they will no longer be elastic. Instead, the molecular kinetic energy declines in proportion to the inelasticity of the collision. The energy device harvests a proportion - 50%??? - of what is not returned in kinetic energy. This is the efficiency of the device, and it is always less than 100% (preserving the 2nd law).

If you are really lucky, the inefficiency losses are emitted as heat and re-absorbed by the atoms of the powering fluid. This can get the system close to 100% net efficiency, but never exactly to 100% and certainly not over.

The amount gathered by the device plus the inefficiency losses that are not returned to the fluid is the amount of energy lost from the fluid per unit of energy gained by the device. These are small amounts at any given moment, but over time, the fluid is chilled down near absolute zero and well below the ability of the fluid to stay, well, fluid. As a solid, the device will be dramatically less efficient, but will still remove energy, pushing the substance closer and closer to zero.

This means the supply of energy isn't "steady" or from "ambient temperatures." It comes from the energy of a specific set of atoms and declines over time.

Now, if we open the system up, we can assume that it gains energy from the things around it, like air, which are heated by (primarily) the sun, the earth (to some extent) extra-terrestrial matter (to a trivial extent) and extra-terrestrial energy (to a ridiculously trivial extent). But the energy here is no longer coming from the fluid in an infinite way normally understood as perpetual motion. The energy here is fusion 93 million miles away and energy of sub-terranean fission & gravitational compaction (which increases heat energy through friction & other means) as well as a few ergs here & there from meteors heating air as the fall, etc. This heat is eventually communicated to the fluid you are using, if it is below the average temperature for the nearby matter.

None of these processes violate laws of thermodynamics. Indeed, they are predicted by them, or at least described by them, since the processes came first.

Hope this helps.

--)->

It's almost easier to think of places where maybe this technology *couldn't* be used, at least not efficiently, than it is to think of real possibilities: power and telephone lines, plus their support towers, wind turbines and their towers, buildings, especially larger and taller ones, every imaginable sort of vehicle (land, water, air), escalators and moving sidewalks, even attached to a dish or clothes washer.

Assuming, that is -- with knowledge that to assume is to tread into a minefield -- the energy return is worth the investment of money, resources, and time.

bicripbicripbicrip,

I'm not postulating perpetual motion from a closed source. In a perfectly insulated box, one could run a tuning fork from energy drawn from the brownian motion. That covers the "motion" definition, without wasting energy in the gradual breakdown of bearings, etc. All the energy that goes into the circuit and motion winds up as heat again, because nothing gets out and that is the lowest form of energy. So, the fork keeps humming, and can be checked with an energy-neutral sampling method. The "perfectly insulated box" would have to be in a perfectly controlled environment, so you'd have a net loss, except for the demonstration.

If this works, it would be the 1st example I've heard of where higher forms of energy can come from heat without using a difference in temperature and runing into the Carnot limit. It would also work even in very motionless envinronments, as long as they conduct heat. If it is cheap to scale up, your air conditioner could run your electric meter backwards.
Bob Stuart

Another great article, I found the information in regards to the human body fascinating, we need to create a device so we can charge our phones or mp3 players on the go! :-)

www.lightingcentre.com/emergency-lighting.html



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