Sunday, November 07, 2010

How Graphene Ping-Pong Balls will Change the World

How Graphene Ping-Pong Balls will Change the World

Steve Coulter
Nov 6, 2010

Graphene is a recently-discovered material of remarkable physical and electrical properties. It is actually found in abundance in nature in the form of graphite. Graphene is simply a single molecular layer of graphite. Graphite is common pencil lead. When you write with a pencil, you create a thin layer of graphite on paper. Apply ordinary scotch tape to that graphite, and you can pull off tiny specks of graphene.

If you had studied these specks of carbon monolayer graphene macromolecules ten years ago, you might have earned the Nobel Prize instead of Andre Geim and Konstantin Novoselov, of the University of Manchester.

Courtesy of Wikipedia, here's a nice drawing of two layers of graphene:




The most intense interest around graphene has been the potential applications in electronics. Graphene has a conductive "cloud" of electrons on each side of this sheet of carbon atoms. These electron clouds can be manipulated to form the smallest possible transistors.

Graphene-based elctronics promise enormous adavances in smaller computer size and reduced power requirements.

We will probably soon see graphene-based photovoltaic solar cells that will be able to generate electricity from sunlight with astonishingly thin, light-weight layers.

Graphene is really a crystalline form of carbon. Diamond is the more familiar crystalline form of carbon. Graphene is stronger than diamond, but it is somewhat elastic.

Crystals have a tendency to be quite stable physical forms. They can often be "grown" in the laboratory under precise conditions. This is also true of graphene, which can be formed in layers deposited on, e.g., copper.

Now consider a factory which might produce spheres of graphene the size of ping-pong balls. The stuff is stronger than diamond, but if we produced spheres of only one molecule thickness, they'd be too fragile to hold their own weight. So we're here considering spheres of sufficient thickness to have the approximate strength of ping-pong balls. One imagines these would have a thickness of thousands of layers. "Thousands of layers" sounds thick, but at atom-sized dimensions, were still talking about microscopic thickness.

These could be formed inside molds of two copper half-spheres. One side of the mold would have a tiny port for a needle-like probe to introduce the carbon substrate to be deposited on the inside of the mold.

Open the mold, and you have a graphene sphere with a miniscule hole. It would probably resembe a soap bubble of the kind you might see a child blow for fun.

Now, put that bubble in a vacuum, and seal the hole with a tiny dot of adhesive tape. There's now a vacuum inside the ball, so the tape hardly even needs adhesive to stay put. Alternatively, it might be possible to deposit more graphene at the hole to complete the sphere.

The peculiar thing about this ping-pong ball is that it's lighter than air. The whole sphere would weigh only perhaps a few milligrams and the vacuum inside would weigh nothing. The sphere would be considerably lighter than if it were filled with helium gas or hydrogen gas. But it would be far stronger than any lighter-than-air balloon.

Since the raw material for graphene is essentially coal or natural gas, it could be possible in the remote future to mass produce vacuum-filled graphene spheres for pennies per liter of vacuum.


GSVB Aircraft

Fill a few common garbage bags with these, tie the bags together, and you can lift yourself into the sky. Bring a parachute before you lift off, please.

Graphene sphere-based lift has powerful advantages over current balloon-based bouyancy using helium or hydrogen gas. Balloons have to permit expansion of gas as they rise, and cannot generally be made into structures of mechanical rigidity or stregth. Only in very large sizes can they be turned into navigable aircraft (dirigibles, or blimps).

Graphene Sphere Vaccuum Bouyancy ( GSVB ) devices offer astounding versatility and applications. You can pack these spheres into lightweight structures comprised primarily of fabric like nylon, shaped in any way you like. The dimensions don't change with altitude, the graphene spheres don't expand or contract.

So lets think about unmanned GSVB aircraft design. These things will hover without using any power. Now put solar cells on the top surface (which will soon be graphene-based and ultralight in weight), and put some lightweight batteries in the structure (which may also soon be graphene-based and ultralight in weight). Add a computer control, radio interface, and propulsion by simple electric fans.

What you now have is a lighter-than-air drone aircraft that can stay aloft for years at a time. With GPS technology, it can hover over a very precise location, at a controlled altitude of anything from a few feet to several miles high. It could be as small as a basketball or as large as the QE2 ocean liner.

Now consider almost ANY application, invention, or device that has ever been conceived of using unmanned aircraft, blimps, ballooons, dirigibles, or satellites. Most of the ideas that have ever been cooked up since the first balloon flight of 1783 can now be carried out with this new and more-versatile technology.

Since these drone aircraft are navigable, they can be released from anyplace on the globe, travel to any point on the globe, stay there as long as desired, and then navigate back to base for maintenance and refitting.

Obviously, surveillance devices would be a prime use. Espionage, security, border control, law enforcement uses spring to mind. Unlike heavier-than-air drones, these craft would be silent. Unlike balloons, they could not be easily shot down with mere bullets.

Many current applications for communication satellites could be deployed more cheaply with GSVB drones. A single communications drone a few miles in altitude might only be able to serve a single metropolitan area, but these drones could simultaneously have functions of modern microwave relay stations.

A cloud of such hovering communications drones could provide TV and internet service to whole nations with minimal ground-based equipment. Laying coaxial cable or fiberoptic lines over miles of ground could soon become obsolete.

Again, with GPS positioning and solar-powered navigation, an entire fleet of communications drones could have almost totally automated operations, carrying limitless total bandwidth over unlimited geographic range.


Shipping and Transportation

The era of lighter-than-air dirigible transportation mostly died with the Hindenburg disaster of 1937. A promising mode of transportation was probably quashed prematurely. GSVB aircraft might bring this transportation mode back.

With GSVB technology, lighter-than-air craft will be far more compact, rigid, and flight-worthy than balloon-based craft, but will still be somwhat bulky, and therefore much slower than current aircraft. It is unlikely that there will be significant demand for mass passenger travel using such aircraft.

Perhaps there might be specialty demand for airliner cruises that might resemble contemporary oceanliner pleasure cruises.

On the other hand, personal helicopter-like craft could be of use in areas where ground transportation is difficult. With automation, on-board radar, and GPS technology, this transportation mode could be pilotless. You might get into your personal GSVB aircraft, punch in your destination with Google Maps, sit back and await your arrival. In the event of mechanical trouble, you might need to be retrieved by someone, but you wouldn't plummet to the ground. Parachute optional here.

Nor is this technology suitable for freight of heavy cargo. However, relatively lightweight, high-value cargo whose delivery is not time-sensitive could be transported by this mode.

In particular, one thinks of the vast trade in consumer goods from China to the US. With unmanned, solar-powered GSVB aircraft, these items could be shippped over the Pacific -- without the fuel expense, labor expense, or maintenance cost of oceanliners. These craft could be packed in Shanghai, programmed, and launched to arrive at a Los Angeles airport in a week or two.


Ladder to Space

Regardless of how great GSVB drone craft might be, mankind will still want to send some items into orbit and then interplanetary space. Current rocket technology makes sending items into orbit very expensive. Engineers have conceived of a number of cheaper alternatives for sending up massive amounts of space cargo. Among these is the idea of a kind of cannon to shoot items ballistically from ground to space.

The force, energy, and speed necessary to deliver items to space ballistically is a daunting challenge, and the cargo so transported would be subjected to ferocious g-forces at launch. One might be able to reduce the difficulty by having a launch platform start the journey at high altitude.

It would be a relatively straightforward matter to design a very, very large GSVB aircraft to carry the air cannon capable of accelerating a payload of hundreds of pounds to near escape velocity.

More extraordinary pie-in-the sky ideas for space delivery have included a "space elevator." GSVB technology could provide the mechanical support for such a structure from the level of ground to tens of miles high.

Climate Change

If graphene spheres can be manufactured at extremely low cost per-unit, a solution to global warming could be at hand.

These spheres can be coated with white or black coatings. The spheres could be made to be heavier on one side, giving a bottom and top to each floating sphere. Put, say, a white titanium dioxide coating on the top, and a black carbon coating on the bottom. Cheap stuff, really. Release many trillions into the atmosphere.

Sunlight hitting the white side of these spheres would reflect light back into space, increasing the "albedo" of the earth to cool it. Heat radiation from the ground need not be reflected back, but would be absorbed by the dark bottom of each sphere, slightly warming the surrounding air in the upper atmosphere, which by convection would deliver the warmth above the sphere-laden layer. Effectively, we'd have a cooling blanket for the earth.

These spheres are very durable and resilient. They could surely be designed to stay aloft for years, even decades before ultraviolet rays and other radiation would break them down to the point of air entry and fall to earth. The stuff is really mere graphite, found in nature, and non-toxic.

Realistically, nobody would launch trillions of individual spheres that could not be retrieved. If we overshot the cooling or needed to turn off the system, the whole globe would be in trouble.

Really, we'd assemble these spheres into massive sheets held together to form rafts the size of multiple square miles. Around the periphery of each massive floating high-altitude raft would be solar-powered, radio-controlled aparatus to permit these rafts to stay flat and horizontal, and be kept to specific locations and permitting the sheets to be retrieved if necessary.

These navigable rafts could be brought to areas for spot-cooling of the globe. Too hot in Europe? Bring a fleet of sheets there for some shade. Areas near the equator could be cooled to become more livable. The Sahara desert could become a temperate zone while also helping to cool the globe as a whole. Saudi Arabia could become a delightful paradise. The Arctic and Antarctic could be kept cool in coming decades and centuries to save polar bears, ice sheets, fisheries, and humanity itself.

Even if the globe as a whole had misgivings about such schemes, individual nations like Saudi Arabia might choose to pursue such plans.

It may be time to start filing patent applications.....

P.S. I cross-posted this over at the half-bakery (http://www.halfbakery.com/idea/Graphene_20Vacuum_20Balls#1289342392). The brilliant minds there have kindly sought to poke holes in this apparent hare-brained scheme. Rough estimates of the strength of graphene would seem to suggest that these spheres might indeed act pretty much as I've suggested here. Actually manufacturing a prototype would be the main hurdle, but advances in handling this material have been developing at a breath-taking pace. I'm quite optimistic a prototype could be built within 2 years.