Materials

Could graphene ripples be tapped into as a clean, limitless energy source?

Could graphene ripples be tapp...
The natural wave-like movements of carbon atoms in graphene could turn the material into a potentially limitless source of energy
The natural wave-like movements of carbon atoms in graphene could turn the material into a potentially limitless source of energy
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University of Arkansas physics professor Paul Thibado led the research
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University of Arkansas physics professor Paul Thibado led the research
A scanning tunneling microscope image of a sheet of graphene
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A scanning tunneling microscope image of a sheet of graphene
The scanning tunneling microscope that the University of Arkansas team used to observe motion in sheets of graphene
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The scanning tunneling microscope that the University of Arkansas team used to observe motion in sheets of graphene
The natural wave-like movements of carbon atoms in graphene could turn the material into a potentially limitless source of energy
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The natural wave-like movements of carbon atoms in graphene could turn the material into a potentially limitless source of energy

As if graphene wasn't versatile enough already, researchers at the University of Arkansas have now found a way for the two-dimensional material to be used as a source of clean and potentially unlimited energy. By tapping into the random fluctuations of the carbon atoms that make up graphene sheets, the scientists can generate an alternating current strong enough to indefinitely power a wristwatch.

Graphene is a lattice of carbon just one atom thick, and its incredible strength and conductivity of electricity and heat mean it might soon start cropping up in everything from light bulbs to dental fillings, microphones, motorbike helmets, water filters, smartphone screens and even heat-dissipating shoes

A scanning tunneling microscope image of a sheet of graphene
A scanning tunneling microscope image of a sheet of graphene

The University of Arkansas researchers stumbled onto a new potential use for the material, when they set out to study the innate movements of graphene using a scanning tunneling microscope. In a phenomenon called Brownian motion, particles suspended in a fluid will randomly move in response to collisions with larger particles in the environment. In the case of a sheet of graphene, the atoms vibrate in response to the temperature around them, making sections of the linked carbon atoms rise and fall like waves on the ocean, sending ripples running through the material.

This motion could be tapped into as a source of energy, using a device the researchers have coined a Vibration Energy Harvester (VEH). The system starts with a sheet of negatively-charged graphene, suspended between two metal electrodes. When groups of atoms rise, the graphene curves and touches the top electrode, creating a positive charge, and when they fall they touch the lower electrode, which creates an alternating current.

A Potential Source of Clean, Limitless Energy

Of course, being on the microscopic scale the amount of energy produced is tiny in the grand scheme of things, but it's all relative. Each individual ripple warps an area measuring 10 nanometers squared, and when that comes in contact with an electrode it produces 10 picowatts of power. That's barely a spark, but that energy increases exponentially when scaled up to patches of graphene measuring 10 microns wide (10,000 nanometers).

The scanning tunneling microscope that the University of Arkansas team used to observe motion in sheets of graphene
The scanning tunneling microscope that the University of Arkansas team used to observe motion in sheets of graphene

In all, those patches can generate enough energy to power a wristwatch, and since it occurs naturally and endlessly, the VEH could create a small battery alternative that theoretically never wears out and never needs charging. Next, the researchers plan to experiment with other materials besides graphene, and eventually the technique could be applied to other small electronic devices, such as pacemakers, hearing aids and other wearables.

The research was published in the journal Physical Review Letters.

Source: University of Arkansas

12 comments
piperTom
Has the second law of thermodynamics been repealed?
Redmercury
Hahah, life certainly flies in the face of the 2nd law, as do many of our creations.
GuillermoRuizCamauer
No, this is using thermal energy from the environment and converting it to electrical energy. The ripples in the graphene sheet come from thermal energy in the environment.
MerlinGuy
To answer the Title's question - No.
Jonathan Colvin
It does rather sounds like it is violating the laws of thermodynamics, unless it is using temperature gradients like a thermoelectric cell. If it just sits there in a uniform temperature bath and harvests energy, that sounds very much like a violation of the laws of thermodynamics.
Paul Muad'Dib
It's not violating any laws of quantum mechanics or thermodynamics. Energy is all around us, we are literally made of it. They probably had to have some very sophisticated device and or specific conditions to make it work, that will be the snag.
highlandboy
So how sure were the researchers that the energy wasn’t being pumped into the graphine by the tunneling electron microscope? The excitation level of an atom (or several atoms) may have been raised by the process of observing it.
Bob
I would have to see this scaled up to the output of a button cell battery to find it useful or would it be huge by comparison?
BanisterJH
I think the second law of thermodynamics doesn't apply at this scale. The graphene, sort of like Maxwell's demon is only responding to the most energetic collisions that are happening from particles at the tip of the high end of the bell curve. Because it's managing to respond to individual collisions, the averaging necessary for the macro scale thermodynamic law to work doesn't occur. Quantum phenomena follow different rules. Another example is how microwaves tuned to the rotational quantum number of water pass right through styrofoam (because it can't pick up energy in exactly that size chunk), but the heat from the rotating water molecules gets trapped inside the cup.
Grunchy
We already have self-winding automatics & solar collectors that can power wrist watches practically indefinitely. I also have a Seiko kinetic which is essentially a mini generator powering the quartz. Micro harvesters & power efficient circuits are the future. An FM harvester is also cheap & simple, there's another option. For example, my Casio "wave ceptor" has an FM receiver to self-adjust to an atomic clock each night at 1am or so, to me it should be using that as an energy source as well!