Une nouvelle façon de produire de l'électricité ! ! !

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Bonjour,

Je viens de découvrir un communiqué du "Institute of Physics" présentant une façon originale de produire de l'électricité.

J'avoue n'en avoir jamais entendu parler auparavant et je voulais savoir si quelqu'un disposait d'autres renseignements à ce sujet.

Il s'agit, si j'ai bien compris, de mettre de l'eau sous pression et de la faire passer dans des "microcanaux" ...

Par ailleurs, j'ai bien trouvé quelque chose sur les

http://www.clarkson.edu/~isokolov/Pu...LTechnique.pdf

mais le lien ne me semble pas évident...


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13 October 2003

Let water power your mobile phone: scientists discover new source of electricity

A new way of generating electricity from flowing water could mean that in the future you will never have to charge up your mobile phone again. Instead of a normal battery, mobile phones could be fitted with a battery that uses water - you just need to pressurise it regularly.

Research published today by the Institute of Physics journal, Journal of Micromechanics and Microengineering reveals a new method of generating electric power by harnessing the natural electrokinetic properties of a liquid such as ordinary tap water when it is pumped through tiny microchannels. The research team from the University of Alberta, Edmonton, Canada, have created a new source of clean non-polluting electric power with a variety of possible uses, ranging from powering small electronic devices to contributing to a national power grid.

The research was led by Professor Daniel Kwok and Professor Larry Kostiuk from the University of Alberta. Professor Kostiuk said: “This discovery has a huge number of possible applications. It’s possible that it could be a new alternative energy source to rival wind and solar power, but this would need huge bodies of water to work on a commercial scale. Hydrocarbon fuels are still the best source of energy but they’re fast running out and so new options like this one could be vital in the future”.

He continued:

“The applications in electronics and microelectronic devices are very exciting. This technology could provide a new power source for devices such as mobile phones or calculators which could be charged up by pumping water to high pressure. What we have achieved so far is to show that electrical power can be directly generated from flowing liquids in microchannels”.

The key to electrical power generation is to create a sustainable electrical charge separation. The physical phenomenon involved in this research is the charge separation that occurs at solid-liquid interfaces due to the dissociation of the solid. As a result, the surface becomes charged and opposite-charged ions in the liquid are attracted to it; while like-charged ions are repelled, resulting in a thin liquid layer with a net charge. This region, known as the Electric Double Layer (EDL), ranges from several nanometers to a few micrometers thick, but is the primary mechanism for charge separation.

The research team constructed a solid-liquid interface as a channel with a diameter similar to the EDL and forced the liquid through this channel, the net charges in the EDL are transported downstream. This preferential transport of one type of ion will create a current, and hence voltage difference across the ends of the channel if the solid is non-conducting.

When an external electric circuit is added by placing electrodes at the ends of the channel, then electrical energy is extracted as current flows between the electrodes. The source of that energy is the work done to push the liquid through the channel. Although the power generated from a single channel is extremely small, millions of parallel channels can be used to increase the power output.

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The paper ‘Electrokinetic Microchannel Battery By Means of Electrokinetic and Microfluidic Phenomena’ by Jun Yang, Fuzhi Lu, Larry W. Kostiuk and Daniel Y. Kwok is published in the Institute of Physics journal, Journal of Micromechanics and Microengineering. It will be published on the web on 20th October 2003 at http://stacks.iop.org/JMM/13/963. The journal’s hompage is http://www.iop.org/EJ/JMM

Institute of Physics journal, Journal of Micromechanics and Microengineering. It will be published on the web on 20th October 2003 at http://stacks.iop.org/JMM/13/963. The journal’s hompage is http://www.iop.org/EJ/JMM
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Perso je pense que l'électricité va devenir commee l'eau une source de conflit. Je pense comme nikola tesla que l'électrcité doit être gratuite pour tout le monde et que toute les sources sont bonne à prendre.

[Cécile]

l'électrcité doit être gratuite pour tout le monde

Ca me semble difficile et dangereux, pour deux raisons :
- elle coûte cher à produire
- la gratuité encouragerait le gaspillage. Or, toutes les études sur les ressources de notre planète montrent qu'il faut au contraire réduire nos consommations, malgré tous les progrès technologiques qu'on peut réaliser.

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Pour information, un complément :



Scientists seek new energy solution in water



A team of scientists has discovered a completely new way to make electricity from flowing water.

The breakthrough, the first new method of electricity production for 160 years, could provide free, clean energy for devices such as mobile phones and calculators.

On a large scale, it could conceivably be used to feed power into the national grid.

Dr David Lynch, Dean of the Faculty of Engineering at the University of Alberta in Canada, where the technology was developed, said: "The discovery of an entirely new way of producing power is an incredible fundamental research breakthrough that occurs once in a lifetime."

A water powered mobile phone would contain a small reservoir pressurised by a hand pump.

Electricity is generated as the water is released and surges through an array of tiny microchannels.

The system relies on the natural 'electrokinetic' effect of a fluid flowing over a solid surface.

An interplay of forces results in a thin layer of water - where it meets the surface - with a net electric charge.

This region is known as the Electric Double Layer (EDL). Normally it goes unnoticed, but the Alberta scientists found that forcing water through a channel with a diameter similar to the EDL produces a flowing current.

The amount of electricity generated by one microchannel is minute. But millions of parallel channels can produce enough power to operate electronic equipment such as a mobile phone.

Professor Larry Kostiuk, a thermodynamicist at the university, hit on the idea after a chance conversation with a fellow scientist about surface-interface phenomena.

Later, he and nanofabrication researcher Professor Daniel Kwok - the other party in the conversation - illuminated a real light bulb by passing water through a porous glass filter.

Their findings were published in the Journal of Micromechanics and Microengineering.

Professor Kostiuk said: "This discovery has a huge number of possible applications. It could be a new alternative energy source to rival wind and solar power, although this would need huge bodies of water to work on a commercial scale."

"Hydrocarbon fuels are still the best source of energy, but they're fast running out and so new options like this one could be vital in the future.

"This technology could provide a new power source for devices such as mobile phones or calculators which could be charged up by pumping water to high pressure."


Story filed: 07:03 Monday 20th October 2003

[A voir en vidéo sur Futura]

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Quelques détails...


Kostiuk and co-workers used a glass disk 2 centimetres in diameter that contained 450 000 circular microchannels, each between 10 and 16 microns across. They held a reservoir of water 30 centimetres above the array and allowed it to flow through the disc under hydrostatic pressure, generating a current of 1500 nanoamps in the process. The power output could be improved by increasing the pressure drop, adjusting the size of the microchannels, decreasing the thickness of the glass disk or using a liquid with a higher salt concentration.

http://www.mece.ualberta.ca/staff/kostiuk.htm

http://www.physicsweb.org/article/news/7/10/11


Si vous avez quelques idées relatives aux applications pratiques, n'hésitez pas à les faire connaître !

Le courant est faible mais pourrait être augmenté en mettant plus de micro-canaux en parallèle...