MIT's Mini-Energy-Harvester A new energy harvesting device converts low-frequency vibrations into electricity. The device, the size of a U.S. quarter, is shown mounted on a stand Arman Hajati

The rumbling you feel driving along a bridge may soon serve a purpose beyond just waking you up behind the wheel. Researchers at MIT have developed a tiny energy-harvester that is able to harness low-frequency vibrations like those made by a bridge or pipeline and converting them to electricity for wireless sensors.

Wireless sensors are used for all kinds of things, from monitoring factory machines and oil pipelines to keeping track of pollution. While the efficiency of their energy consumption has improved, the sensors' batteries still need to be changed occasionally. MIT's device, a microelectromechanical system (we prefer the term energy-harvester) makes electricity from the vibrations of foot traffic and other low-power energy sources from the environment, potentially removing the need for batteries completely.

The quarter-sized energy-harvester has improved on the designs of similar devices by taking inspiration from the bridges themselves. MIT's energy-harvester consists of a microchip with a bridge-like structure anchored at either end. On the bridge is a weight sitting on one layer of piezoelectric material (PZT), which naturally gathers electric charge when faced with mechanical stress. Other devices use a cantilever beam instead of a bridge to pick up vibrations, which is much less efficient. MIT's design picks up a wider range of vibrations and produces 100 times more energy than any other harvester available.

The next step for the project is to get the device to pick up lower-frequency vibrations and generate at least 100 microwatts of power, a target that would be able to power a whole network of wireless sensors.

[MIT]

17 Comments

Combining today's technologies, I believe we can come close to perpetual energy. To those who don't know what that is..it means that a machine is auto-sufficient..basically generating its own energy and/or not loosing any. I don't think we are there yet for perpetual but combining; solar, battery, wind vibration heat and movement into one...we get close i'm sure..

What do you guys think...

Big deal. My grandfather made a radio that used radio waves to power it almost 100 years ago.

also we have made great advancements in oils that reduce friction and engines that are so much more efficient. What are we waiting for to combine this into one? or at least try.. I've heard of soo many university projects where cars could reach 80mpg...then what happens...it gets patented and dissapears...waiting for our dear conglomerates to decide when is the proper time to introduce such technologies and how to market them properly to get every possible dollar out of the consumer... anyways...i think we could be light years ahead.. but because of these business plans...marketing schemes..we are offered out-dated products..

light years ahead ppl...really

This is a bit off topic, but it is essentially a reply to midoman's talks about oil and mpg, etc.
External combustion engines are the way of the future, using steam to drive some sort of engine like a corkscrew super charger, turbine or even conventional piston engines. Even heating up a mass of NaCl to make it molten then using that later on to boil the water into steam is an idea which holds promise.
Internal Combustion engines are inefficient, prone to excessive wear and have too many 'economy boosting' attachments on them. I believe that with steam, the same efficiency will be able to be achieved with far less additional components to the basic running gear of the engine.

I do a lot of data entry in the office each day. Loads of email composition and replies. Thousands of keystrokes making my keyboard sound like a mini machine gun. This morning I was wondering if there could be a way to somehow tap into those tippity taps per minute. I was stumped... that is until I stumbled across this article tonight! I think that an energy-generating keyboard would be a compelling proof of concept project to demonstrate this technology. I wonder how much electricity I would be able to generate by the end of the day. Probably not much. Well then how about a skyscraper full of office workers?

Can someone do the math for me?

The only practical use of keystroke power is to transmit the data without need for wires, But this saves as serious amount of wire! for a keyboard which does this visit Algra at http://www.algra.ch/files/PR%20DP%20Wireless%20engl.pdf - and for a system which allows you to turn on lighting and control the energy use inside a building, powered by keystrokes, ambient light and internal temperature differences see EnOcean

As I flushed the toilet and watched the water flow away, I wondered if it would be practical to retrofit a highrise building with a scaled down hydroelectric generator to recover some of the energy from the flowing water. And if we can do that why cant we install the same thing on storm drains and major sewer lines? And here is another thought, why not make portable hydroelectric generators that float, and are tethered, to provide electricity in flood conditions. Imagine getting free power from the same disaster that caused the outage! Would have been nice to have this year with all the flooding. Just a few ideas from my strange brain.

@KnotTubeRight
Brb, stealing your idea! Those are actually some really great ideas. Come to think of it, if they just set up some turbines in the gas lines they could get some power back too as users required the gas, it would need to go past the turbines.

You people are forgetting that none of these ideas no matter how good will never happen due to the simple fact...MONEY...until you stop hearing about a green project such as a company putting up Solar or Wind Power and the main odjection being money. Until this does NOT happen we are basically screwed. There is 0 reason money should ever be a reason to save our selfs and our planet hate to tell everyone if we don't have a place to live does not matter how much money it might of costs or how much you might of saved you are dead....

@Delkomatic
There are many non-profiting energy plants out there. Nuclear and dams are an example. But money can be a great incentive for people to develop new ideas. It creates a sort of motivation to build something because of the idea that if you do you can live more easily or even live at all. Things cost money and unless you are willing to spill up all the dough or someone else is willing to cough up the dough, the driving force needs to be money. If it is, other investors pour money into the project that helps pay for R&D and manufacturing.
That or let the government do the research and cough up taxes.

You have a better solution?

jefro, im gonna find you and hit you so damn hard. you suck.
X
(SUCK IT)

jefro,

"Crystal diode powered radio."

"....A crystal radio receiver, also called a crystal set or cat's whisker receiver, is a very simple radio receiver, popular in the early days of radio. It needs no battery or power source and runs on the power received from radio waves by a long wire antenna. It gets its name from its most important component, known as a crystal detector, originally made with a piece of crystalline mineral such as galena. This component is now called a diode....

....The rectifying property of crystals was discovered in 1874 by Karl Ferdinand Braun, and crystal detectors were developed and applied to radio receivers between 1894 and 1906 by Jagadish Chandra Bose G. W. Pickard and others...."

http://en.wikipedia.org/wiki/Crystal_radio

@Midoman
I like your idea about perpetual motion. Here's a spin on that, cars are made of a lot of steel. Steel is attracted to magnets. Just take a really strong magnet and hang it from a pole just in front of the car, the steel in the car will be pulled forward by magnetism. Voila, perpetual motion. If only it were that simple.
But in all seriousness, I believe that I know of a perpetual motion machine already in existence. We all know of it. We all experience it every day. It is us and we are it. It is the universe. It has always been here and will always be here. How much more perpetual can you get? We will find a theory of everything someday. Until then, mankind will rape this planet,(and probably others,) to fulfill his never ending desire for power. Don't get me started on power. "When the power of love is greater than the love of power, the world will know peace." Jimi Hendrix.

We need to be careful not to confuse self-powered machines with mythical "perpetual motion machines". The difference is that self-powered machines use a power source derived from their environment (such as rectified radio waves or vibrations converted to electricity through the piezoelectric effect) have an efficiency of less than 100% and are therefor actually POSSIBLE.
Perpetual motion machines have a theoretical efficiency greater than 100%, and therefor are completely IMPOSSIBLE.

Maybe using the movement of the shocks on your car could power something.

Using shock or impact mechanics to harvest energy is a very hard task to do due to its frequency and force applied. Piezo material are known for its brittleness, especially the PZT. Vibrations will do.

This design actually is very good compare to all the devices out there because it can altered itself for bandwidth variations to optimize its efficiency. Unless you can make sure your the frequency source is constant, e.g. make sure the force you applied on the keyboard is same the whole time, this device will be proven powerful and had the highest efficiency.

hi



June 2013: American Energy Independence

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