Researchers demonstrate new technique for generating electricity

November 10, 2014 by Olli Ernvall
Schematic of the new electricity generation technique. Bodies 1 and 2 have different work functions.

Research scientists at VTT Technical Research Centre of Finland have demonstrated a new technique for generating electrical energy. The new method can be used in harvesting energy from mechanical vibrations of the environment and converting it into electricity. Energy harvesters are needed, for example, in wireless self-powered sensors and medical implants, where they could ultimately replace batteries. In the future, energy harvesters can open up new opportunities in many application areas such as wearable electronics.

Research scientists at VTT have successfully generated energy by utilizing the charging phenomenon that occurs naturally between two bodies with different work functions. Work function is the amount of energy needed to remove an electron from a solid and it determines, for example, the well-known photoelectric effect. When two conducting bodies with different work functions are connected to each other electrically, they accumulate opposite charges. Moving of these bodies with respect to each other generates energy because of the attractive electrostatic force between the opposite charges. In VTT's experiment the energy generated by this motion was converted into useful electrical power by connecting the bodies to an external circuit. This new technique also works with semiconductors.

In many sensor applications and such as pacemakers, electricity is typically provided by batteries. Research into small that turn mechanical vibration into electricity has focused on piezoelectric and electrostatic devices. Unlike these devices VTT's technique does not require an integrated battery, electrets or piezo materials.

VTT estimates that the new electricity generation technology could be introduced on an industrial scale within three to six years. Energy harvesters and new sensing solutions are among the projected megatrends of the near future. Energy harvesters can replace batteries and other energy sources in applications where maintenance is difficult or impossible.

The findings of the study were published in the Scientific Reports online journal.

Explore further: Flexible plastics that turn mechanical vibrations into electrical energy

More information: "Harvesting Vibrational Energy Using Material Work Functions". Scientific Reports 4, Article number: 6799 DOI: 10.1038/srep06799

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6 comments

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bjonssen
2.3 / 5 (3) Nov 10, 2014
I believe that our US patent system is broken allowing wealthy entities to buy patents that directly compete with their own aging products (petroleum products) and allowing other countries to take the lead in potentially lucrative and advancing ideas.

Very anti-American.
stabilizer
4 / 5 (3) Nov 10, 2014
Actually this isn't really a new idea. It is apparently a new set of materials that can harness the idea for new applications. As such, it isn't new physics, but it might well be an extremely significant discovery. Imagine if we implant children with these, and use the power to run their cell phones, video games, etc. This would assure that the only way they can live their virtual lives is by having a real life. Get out and run so you can play dungeons of doom, or whatever. They also need to add solar skin, which we can plate the kids with so they have to be out in the sun part of the day. Of course, they will probably just pay for 30 minutes sitting on a paint miixer in a field while they play video games. Doggone kids and their toys, now where did my Iphone go???
Modernmystic
not rated yet Nov 10, 2014
VTT estimates that the new electricity generation technology could be introduced on an industrial scale within three to six years.


Oh yeah? How much a kilowatt hour? Are the ambient vibrations going all the time or is it intermittent? How much of the time? What's the maintenance? What's the land footprint? What materials (ie rare earth's etc) go into this technology? At what environmental cost?

Great for pacemakers maybe. Absolute crap for industrial applications...
Tektrix
5 / 5 (1) Nov 10, 2014
We will be seeing a lot more devices that need only micro-currents of power- devices that are much smaller than the batteries used to power them. And often, because they are so small, these tiny devices will be located in inaccessible or hazardous locations, where changing a battery is out of the question. Or used in applications where batteries are simply too expensive or cumbersome- package and store shelf labels for instance. Energy harvesters are the obvious choice for these little circuits, especially if they are cheap, non-toxic, and reliable.

And you're right, stabilizer, charge separation to generate energy isn't new- Kelvin built one based on falling water drops in the late 1800's: http://en.wikiped..._dropper
Eikka
5 / 5 (3) Nov 17, 2014
Oh yeah? How much a kilowatt hour?


That's not really the question.

Think of it as a generator that can be constructed without reliance on neodymium imported from China. Doesn't matter what you use to turn it, it's still a better idea.
gkam
1 / 5 (1) Nov 17, 2014
Mystic does not get it: This harvests the energy which would be wasted by vibration.

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