Category Archives: levitation

Artificial muscles using folded graphene

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Folded Graphene Concept

Two years ago I wrote a blog on future hosiery where I very briefly mentioned the idea of using folded graphene as synthetic muscles:

https://timeguide.wordpress.com/2015/11/16/the-future-of-nylon-ladder-free-hosiery/

Although I’ve since mentioned it to dozens of journalists, none have picked up on it, so now that soft robotics and artificial muscles are in the news, I guess it’s about time I wrote it up myself, before someone else claims the idea. I don’t want to see an MIT article about how they have just invented it.

The above pic gives the general idea. Graphene comes in insulating or conductive forms, so it will be possible to make sheets covered with tiny conducting graphene electromagnet coils that can be switched individually to either polarity and generate strong magnetic forces that pull or push as required. That makes it ideal for a synthetic muscle, given the potential scale. With 1.5nm-thick layers that could be anything from sub-micron up to metres wide, this will allow thin fibres and yarns to make muscles or shape change fabrics all the way up to springs or cherry-picker style platforms, using many such structures. Current can be switched on and off or reversed very rapidly, to make continuous forces or vibrations, with frequency response depending on application – engineering can use whatever scales are needed. Natural muscles are limited to 250Hz, but graphene synthetic muscles should be able to go to MHz.

Uses vary from high-rise rescue, through construction and maintenance, to space launch. Since the forces are entirely electromagnetic, they could be switched very rapidly to respond to any buckling, offering high stabilisation.

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The extreme difference in dimensions between folded and opened state mean that an extremely thin force mat made up of many of these cherry-picker structures could be made to fill almost any space and apply force to it. One application that springs to mind is rescues, such as after earthquakes have caused buildings to collapse. A sheet could quickly apply pressure to prize apart pieces of rubble regardless of size and orientation. It could alternatively be used for systems for rescuing people from tall buildings, fracking or many other applications.

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It would be possible to make large membranes for a wide variety of purposes that can change shape and thickness at any point, very rapidly.

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One such use is a ‘jellyfish’, complete with stinging cells that could travel around in even very thin atmospheres all by itself. Upper surfaces could harvest solar power to power compression waves that create thrust. This offers use for space exploration on other planets, but also has uses on Earth of course, from surveillance and power generation, through missile defense systems or self-positioning parachutes that may be used for my other invention, the Pythagoras Sling. That allows a totally rocket-free space launch capability with rapid re-use.

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Much thinner membranes are also possible, as shown here, especially suited for rapid deployment missile defense systems:

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Also particularly suited to space exploration o other planets or moons, is the worm, often cited for such purposes. This could easily be constructed using folded graphene, and again for rescue or military use, could come with assorted tools or lethal weapons built in.

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A larger scale cherry-picker style build could make ejector seats, elevation platforms or winches, either pushing or pulling a payload – each has its merits for particular types of application.  Expansion or contraction could be extremely rapid.

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An extreme form for space launch is the zip-winch, below. With many layers just 1.5nm thick, expanding to 20cm for each such layer, a 1000km winch cable could accelerate a payload rapidly as it compresses to just 7.5mm thick!

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Very many more configurations and uses are feasible of course, this blog just gives a few ideas. I’ll finish with a highlight I didn’t have time to draw up yet: small particles could be made housing a short length of folded graphene. Since individual magnets can be addressed and controlled, that enables magnetic powders with particles that can change both their shape and the magnetism of individual coils. Precision magnetic fields is one application, shape changing magnets another. The most exciting though is that this allows a whole new engineering field, mixing hydraulics with precision magnetics and shape changing. The powder can even create its own chambers, pistons, pumps and so on. Electromagnetic thrusters for ships are already out there, and those same thrust mechanisms could be used to manipulate powder particles too, but this allows for completely dry hydraulics, with particles that can individually behave actively or  passively.

Fun!

 

 

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Using carbon to make a Landspeeder or hoverboard

You are probably familiar with Marty McFly’s hovering skateboard and the Star Wars Landspeeder hover-car. How feasible are they? Like most futurists, I get asked about flying cars every week.

Let’s dispose of pedantry first. Flying cars do exist. Some are basically vertical take off planes without the wings, using directed air jets to stay afloat and move. I guess you could use a derivative of that to make a kind of land-speeder. The hovercraft is also a bit Landspeedery, but works differently. Hovercraft are OK, but a Landspeeder floats higher off the ground and without the skirt so it it’s no hovercraft. Well, we’ll see.

Carbon can be used to make a Star Wars Landspeeder or Marty McFly’s hover board from Back to the Future. Both would be almost silent, with no need for messy skirts, fans, or noisy ducted air jet engines, and could looks like the ones in the films. Or you could employ a designer and make one that looks nice instead.

 

Anti-gravity may one day be possible but we don’t know how to do that yet. Conventional wisdom says that either you use noisy ducted air jets or a hovercraft skirt, or else magnetic levitation, as the Landspeeder is meant to be anyway, which can be done but so far needs a special metal track. It couldn’t work on a pavement or side-walk. You can’t use simple magnetic repulsion effects to levitate above concrete or asphalt.

I pointed out a good while ago with my linear induction bicycle lane idea that you could use a McFly style hover-board on it. My daughter’s friends were teasing me about futurists and hoverboards – that’s why.

http://timeguide.wordpress.com/2013/01/30/hover-boards/

That would work. It would be totally silent. However, the Landspeeder didn’t stay on a linear induction mat laid just under the entire desert surface, did it? That would just be silly. If you had a linear induction mat laid under the entire desert surface, you’d put some sort of horse shoes on your camel and it could just glide everywhere at high speed. You wouldn’t need the Landspeeder.

Ignoring conventional wisdom, with some redesign, you can use magnetic levitation to produce a landspeeder or hoverboard that would work on a sidewalk, pavement, road, or even a desert surface. Not water, not the way McFly did anyway. You could also make the hover tanks and everything else that silently hovers near the ground in sci-fi films. And force fields. Sand, asphalt and concrete aren’t made of metal but that doesn’t matter.

Graphene is a really good conductor. Expensive still, but give it a few years and it’ll be everywhere. It is a superb material. With graphene, you can make thin tubes, bigger than carbon nanotubes but still small bore. You could use those to make coils around electron pipes, maybe even the pipes themselves. Electron pipes are particle guides along which you can send any kind of charged particles at high speed, keeping them confined using strong magnetic fields, produced by the coils around the pipe, a mini particle accelerator. I originally invented electron pipes as a high bandwidth (at least 10^22bit/s) upgrade for optical fibre, but they have other uses too such as on-chip interconnect, 3d biomimetic microprinting for things like graphene tubes, space elevator rope and others. In this case, they have two uses.

First you’d use a covering of the pipes on the vehicle underside to inject a strong charge flux into the air beneath the hoverboard (if you’re a sci-fi nut, you could store the energy to do this in a super-capacitor and if you’re really twisted you might even call it a flux capacitor, since it will be used in the system to make this electron flux). The result is a highly charged mass of air. Plasma. So what?

Well, you’d also use some rings of these tubes around the periphery of the vehicle to create a very strong wall of magnetic field beneath the vehicle edge. This would keep the charged air from just diffusing. In addition, you’d direct some of them downwards to create a flow of charged air that would act to repel the air inside, further keeping it confined to a higher depth, or altitude, so you could hover quite a distance off the ground.

As a quick but important aside, you should be able to use it for making layered force fields too, (using layers of separated and repelling layers of charged air. They should resist small forces trying to bend them and would certainly disrupt any currents trying to get through. But maybe they would not be mechanically strong ones. So, not strong enough to stop bullets, but enough to stop or severely disrupt charges from basic plasma weaponry, but there aren’t many of them yet so that isn’t much of a benefit. Anyway… back to the future.

Having done this, you’ll hopefully have a cushion of highly charged air under your vehicle, confined within its circumference, and some basic vents could make up for any small losses. I am guessing this air is probably highly conductive, so it could be used to generate both magnetic and electrostatic forces with the fields produced by all those coils and pipes in the vehicle.

So now, you’d basically have a high-tech, silent electromagnetic hovercraft without a skirt to hold the air in, floating above pretty much any reasonably solid surface, that doesn’t even have to be smooth. It wouldn’t even make very much draft so you wouldn’t be sitting in a dust cloud.

Propulsion would be by using a layer of electron pipes around the edge of the vehicle to thrust particles in any direction, so providing an impulse, reaction and hence movement. The forward-facing and side facing pipes would suck in air to strip the charge off with which to feed the charged air underneath. Remember that little air would be escaping so this would still be silent. Think of the surface as a flat sheet that pushes ionised air through quite fast using purely electromagnetic force.

Plan B would be to use the cover of electron pipes on the underside to create a strong downward air flow that would be smoothed and diffused by pipes doing the side cushion bit. Neither would be visible and spoil the appearance, and smooth flow could still be pretty quiet. I prefer plan A. It’s just neater.

There would be a little noise from the air turbulence created as the air flow for propulsion mixes with other air, but with a totally silent source of the air flow. So basically you’d hear some wind but not much else.

Production of the electron pipes is nicely biomimetic. Packing them closely together in the right pattern (basically the pattern they’d assume naturally if you just picked them up) and feeding carbon atoms with the right charge through them at the right intervals could let you 3D print a continuous sheet of graphene or carbon nanotube. Biomimetic since the tube would grow from the base continuously just like grass. You could even produce an extremely tall skyscraper that way. 30km is a reasonable limit for 2045, but recent figures for graphene strength suggest that structures up to 600km may be theoretically possible by the end of the century.

Could it work. Yes, I think so. I haven’t built a prototype but intuitively it should be feasible. Back to the Future Part 1 takes Marty to Oct 21, 2015. We just passed that and two prototypes hoverboards were available then. Sadly, neither used my technique but a good lab could just about make most and maybe all of this capability any time soon. On the other hand, Star Wars is set very far away and very long ago, so we’re a bit late for that one.

So, feasible, and just a little way in the future. Pretty much the entire vehicle could be carbon based. Carbon fibre and carbon foam would provide most of the structure, graphene windows for streamlining, strength, protection and transparency, graphene and carbon nanotubes for engines, power and levitation.