Physics

Graphene tractor beams could one day redirect lightning strikes

Graphene tractor beams could o...
A new study has demonstrated how a tractor beam containing trapped graphene microparticles could one day redirect lightning strikes
A new study has demonstrated how a tractor beam containing trapped graphene microparticles could one day redirect lightning strikes
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A new study has demonstrated how a tractor beam containing trapped graphene microparticles could one day redirect lightning strikes
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A new study has demonstrated how a tractor beam containing trapped graphene microparticles could one day redirect lightning strikes
Electrical sparks propagate along a chain of graphene microparticles in a tractor beam. In this test the electrodes are 30 mm apart, three times further apart than other runs
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Electrical sparks propagate along a chain of graphene microparticles in a tractor beam. In this test the electrodes are 30 mm apart, three times further apart than other runs
Professor Andrey Miroshnichenko (left) and Dr Vladlen Shvedov (right) in the lab
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Professor Andrey Miroshnichenko (left) and Dr Vladlen Shvedov (right) in the lab
A "lightning" bolt in the lab follows the path of a laser tractor beam
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A "lightning" bolt in the lab follows the path of a laser tractor beam
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Lightning strikes are a major trigger for wildfires, including the record-breaking blazes that devastated Australia, California and other regions this year. An international research team has now demonstrated a method that could effectively control where lightning strikes, using graphene microparticles trapped in a “tractor beam.”

A bolt of lightning can become hotter than the surface of the Sun – so it’s no surprise that when they hit dry grass, shrubs or trees, they can spark fires. Couple that with the fact that climate change is reducing rainfall in already fire-prone areas while potentially increasing the intensity of lightning storms, and you’ve got a dangerous recipe. This year’s devastation could become a worryingly regular occurrence.

But what if we had a portable device that can be carried out to the site of a storm, and set up to guide lightning away from fire hazards or vulnerable buildings? Such a breakthrough may be a step closer to reality, thanks to a new study from researchers at Australian National University, the University of New South Wales, Texas A&M, and the University of California, Los Angeles.

A "lightning" bolt in the lab follows the path of a laser tractor beam
A "lightning" bolt in the lab follows the path of a laser tractor beam

The team demonstrated the concept in a lab, by first recreating stormy conditions using two charged parallel plates separated by a small gap of air. Normally, jolts of electricity jump between the plates at random, mimicking lightning, but by using some clever physics, the researchers were able to control where the bolts traveled.

“We had a relatively simple setup,” Andrey Miroshnichenko, co-author of the study, tells New Atlas. “It was just two conducting plates, which were charged. And then we introduced particles, hot particles inside a tractor beam, which induces the discharge between two plates. It showed that we can control where and when the discharge should happen, between the two plates under lab conditions.”

In nature, lightning is essentially electricity looking for the most conductive path to complete a circuit from cloud to cloud, or cloud to ground. For us casual observers, that path often appears random as the bolts arc and fork across the sky, but they’re following very specific channels of ionized gas, which are more conductive than the air around them.

In theory then, you could help guide where lightning strikes by giving it a very conductive path to follow. And that’s where the graphene microparticles come in. With its light weight, strength, and excellent thermal and electrical conductivity, a chain of graphene particles can create the perfect path.

“We introduced hot graphene particles in between (the plates), and in order to do that we used what was called a tractor beam,” Miroshnichenko tells us. “A tractor beam is a hollow core laser beam, and particles were trapped inside. And that’s how we delivered particles in the space between the plates.”

Professor Andrey Miroshnichenko (left) and Dr Vladlen Shvedov (right) in the lab
Professor Andrey Miroshnichenko (left) and Dr Vladlen Shvedov (right) in the lab

This kind of tractor beam won’t be capturing spaceships anytime soon, but it has been shown to work on particles for around a decade now. Essentially, particles are trapped in the center of the hollow laser beam, because whenever they drift into the light a small thrust known as the photophoretic force pushes them back into the darker center.

Energy from the laser also happens to push the particles forward, and heats them up. When they get hot enough, they ionize the air around them, creating a path along the laser beam that’s more conductive – so it’s all but irresistible for lightning.

Put simply, wherever you point this tractor beam, lightning is much more likely to strike.

"We have an invisible thread, a pen with which we can write light and control the electrical discharge to within about one tenth the width of a human hair," says Miroshnichenko.

The effects are clear in videos of the lab experiments (below). The first clip shows the beam of graphene microparticles, which are glowing so brightly from the heat that you can’t even see the electrical discharge zap through them.

In the second clip, the lightning is much more obvious – the first bolt follows right along the beam. After that the beam is switched off, but the next few strikes still follow the rough path left behind by the residual heat. By the end of the video, the lightning goes back to its regular random pattern, highlighting just how much a difference it makes when controlled.

Tractor beam control of lightning strikes

While graphene was a handy test subject, it may not be necessary. Miroshnichenko says that eventually the tractor beam could be made to trap and heat up whatever particles are on hand, including potentially those already in the ambient air.

Another benefit of the new system is that it can be done with relatively low-powered lasers, operating on the scale of milliwatts. Other teams have tried directly ionizing gases using pulses of high-powered lasers, but this technique isn’t as efficient and can’t propagate as far as the tractor beam.

While it’s so far only been tested on small scales in the lab, Miroshnichenko says the system should be relatively straightforward to scale up. The technology is already there, and he hopes to have field tests completed within the next three or four years.

Ultimately, having machines that effectively control where lightning strikes could be invaluable for reducing wildfires, and the huge environmental and property damage and loss of life they incur.

Electrical sparks propagate along a chain of graphene microparticles in a tractor beam. In this test the electrodes are 30 mm apart, three times further apart than other runs
Electrical sparks propagate along a chain of graphene microparticles in a tractor beam. In this test the electrodes are 30 mm apart, three times further apart than other runs

There are still major hurdles to overcome though. At this stage, the experiment was all about inducing the discharge and channeling it to a desired point. Natural lightning is obviously far more powerful than sparks between two small plates, and the team doesn’t yet have the tech to deal with that energy. It would need to be dissipated into the ground the way a lightning rod works, but doing so safely is its own challenge.

In the meantime, the lab-scale technology could also find applications in manufacturing such as welding, or in medicine as a kind of optical scalpel to remove cancerous tissue.

The research was published in the journal Nature Communications.

Source: Australian National University

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10 comments
Techrex
I am throwing spitballs here, but, if lightning strikes occur very often in certain places, like Florida beaches, and a unique lake where they have unbelievable lightning strikes all of the time, could this device be used to direct the lightning strikes to lightning rods, that are grounded in a steel mill's blast furnace' s pool of molten metals? The grounded lightning bolts charges, would be wired into these special carbon rods that Union Carbide makes for steel mill fernances, that use electricity to superheat the contained pool of molten iron or steel. Why should we do that? If the entire world has an insurmountable problem with the disposal of many types of toxic wastes, why not use the power of lightning bolts to destroy it, by dumping it into these superhot molten pool of metals? The resulting gases would be reduced to their single basic elements, which could be commercially recycled for industrial applications, or vented directly into the atmosphere safely. We have always had this 'Brute Force' method of destroying toxic materials, but nobody could afford the costly electric bills!
piperTom
It tickles me to read about "tractor beams" and it's still joyous when it turns out to be a hallow laser trapping particles in the air. Still, it's hard to see how this could ever be practically deployed to fire prone areas -- especially considering the competing method is a simple, inert metal rod just a bit taller than the surrounding trees.
guzmanchinky
Stuff of science fiction made real. I live in California and this kind of tech cold not come soon enough...
Bob Bogen
if you can predict where lightning is going to strike (harvest it), why can't you hook it up to a battery and generate piles of electricity??
notarichman
i think it has already been shown that rockets can attract lightning. so small hobby rockets going up with the same lasar beam might also work and be cheaper, easier?
riczero-b
Does anyone else see the military potential as a disruptor of enemy electronics or high energy weapons? Or indeed the graphene could carry an electron pulse in the opposite direction- Thor' s hammer!
anthony88
A weapon to strike enemies twice and thrice...
FB36
Isn't graphene toxic to breathe?

I think I had read about other experiments in the past, doing lightning/arc channeling by using only air ionizing UV laser or femtosecond laser!

This kind of tech could be actually much more useful than only redirecting/collecting lightning strikes!
Imagine tasers which can be fired from a distance w/o needing wires!
Imagine larger such tasers which can be used by law enforcement to stop cars and/or drones!
Trylon
A balloon or kitesail with a conductive aluminum grounding cable as a tether would be much cheaper and easier. Basically a supertall temporary lightning rod. You could replace it for a few hundred dollars at most if a lightning strike destroys it, which is more than I can say for a laser graphene gadget.
Baker Steve
Unless I've misunderstood, if this were scaled up to deal with real lightning it would discharge down the tractor beam and vaporize the kit that was generating it, a hi-tech equivalent of 'The operation was successful but the patient died.'