Category Archives: emergencies

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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Instant buildings: Kinetic architecture

Revisiting an idea I raised in a blog in July last year. Even I think it was badly written so it’s worth a second shot.

Construction techniques are diverse and will get diverser. Just as we’re getting used to seeing robotic bricklaying and 3D printed walls, another technique is coming over the horizon that will build so fast I call it kinetic architecture. The structure will be built so quickly it can build a bridge from one side just by building upwards at an angle, and the structure will span the gap and meet the ground at the other side before gravity has a chance to collapse it.

The key to such architecture is electromagnetic propulsion, the same as on the Japanese bullet trains or the Hyperloop, using magnetic forces caused by electric currents to propel the next piece along the existing structure to the front end where it acts as part of the path for the next. Adding pieces quickly enough leads to structures that can follow elegant paths, as if the structure is a permanent trace of the path an object would have followed if it were catapulted into the air and falling due to gravity. It could be used for buildings, bridges, or simply art.

It will become possible thanks to new materials such as graphene and other carbon composites using nanotubes. Graphene combines extreme strength, hence lightness for a particular strength requirement, with extreme conductivity, allowing it to carry very high electric currents, and therefore able to generate high magnetic forces. It is a perfect material for kinetic architecture. Pieces would have graphene electromagnet circuitry printed on their surface. Suitable circuit design would mean that every extra piece falling into place becomes an extension to the magnetic railway transporting the next piece. Just as railroads may be laid out just in front of the train using pieces carried by the train, so pieces shot into the air provide a self-building path for other pieces to follow. A building skeleton could be erected in seconds. I mentioned in my original blog (about carbethium) that this could be used to create the sort of light bridges we see in Halo. A kinetic architecture skeleton would be shot across the divide and the filler pieces in between quickly transported into place along the skeleton and assembled.

See https://timeguide.wordpress.com/2016/07/25/carbethium-a-better-than-scifi-material/. The electronic circuitry potential for graphene also allows for generating plasma or simply powering LEDs to give a nice glow just like the light bridges too.

Apart from clever circuit design, kinetic architecture also requires pieces that can interlock. The kinetic energy of the new piece arriving at the front edge would ideally be sufficient to rotate it into place, interlocking with previous front edge. 3d interlocking is tricky but additional circuitry can provide additional magnetic forces to rotate and translate pieces if kinetic energy alone isn’t enough. The key is that once interlocked, the top surface has to form a smooth continuous line with the previous one, so that pieces can move along smoothly. Hooks can catch an upcoming piece to make it rotate, with the hooks merging nicely with part of the new piece as it falls into place, making those hooks part of a now smooth surface and a new hook at the new front end. You’ll have to imagine it yourself, I can’t draw it. Obviously, pieces would need precision engineering because they’d need to fit precisely to give the required strength and fit.

Ideally, with sufficiently well-designed pieces, it should be possible to dismantle the structure by reversing the build process, unlocking each end piece in turn and transporting it back to base along the structure until no structure remains.

I can imagine such techniques being used at first for artistic creations, sculptures using beautiful parabolic arcs. But they could also be used for rapid assembly for emergency buildings, instant evacuation routes for tall buildings, or to make temporary bridges after an earthquake destroyed a permanent one. When a replacement has been made, the temporary one could be rolled back up and used elsewhere. Maybe it could become routine for making temporary structures that are needed quickly such as for pop concerts and festivals. One day it could become an everyday building technique. 

High-rise external evacuation

A quick googling turned up this great idea, using an escape chute attached to the top of a fire crane. The chute has a fireproof external layer and people slow or speed their descent in it simply by varying their posture. Read the pdf for more details:

http://www.escapeconsult.biz/download.php?module=prod&id=26

But the picture tells all you need to know. You can see it reaches very high, up to 100m with the tallest fire appliance.

It is a great idea, but you can still see how it could be improved, and the manufacturer may well already have better versions on the way.

Firstly, the truck is already leaning, even though it has extendable feet to increase the effective base area. This affects all free-standing fire rescue cranes and ladders (suspension ladders, or ladders able to lean against a wall obviously include other forces). Physics dictates that the center of gravity, with the evacuees included, must remain above the base or it will start to topple. The higher it reaches and the further from the truck, the harder that becomes, and the fewer people can simultaneously use the escape chute. Clearly if it is go even higher, we need to find new ways of keeping the base and center of gravity aligned, or to prevent it toppling by leaning the ladder securely against a sound piece of wall that isn’t above a fire.

One solution is obvious. Usually with a high-rise fire, a number of fire appliances would be there. By linking several appliances to the ladder in a stable pattern, the base area then becomes far larger, the entire area enclosed by the combined appliances. At the very least, they can spread out across a street, and sometimes as in the Grenfell Tower fire, there is a lot of nearby space to spread over. With a number of fire appliances, the crane is also not limited to the carrying capacity of a single appliance.

If theses are specialist hi-rise appliances, one or two would carry telescopic arms to support the rescue equipment, with one or more trucks using tension wires to increase the base area.

We also need to speed up entry to the chute and preferably make it accessible to more windows. The existing system has access via a small hole that might be slow to pass through, and challenging for larger people or those with less mobility. A funneled design would allow people to jump in from several windows or even drop from a floor above. Designing the access to prevent simultaneous arrivals at the chute is easy enough, even if several people jump in together

Also, it would be good if the chute could take evacuees away from the building and flames as fast as possible. Getting them to the ground is a lesser priority. Designing the funnel so it crosses several windows, with a steep slope away from the building (like an airplane escape slide) before it enters the downward chute would do that.

Another enhancement would be that instead of a broad funnel and single chute, a number of chutes could be suspended, with one for each window. Several people would be able to descend down different chutes at the same time. with a much broader base area, toppling risk would still be greatly reduced.

If a few support arms could be extended from the crane towards the building, that would provide extra stability until their strength (or building fabric) is compromised by fire. Further support might sometimes be available from window cleaning platform apparatus that could support the weight of the rescue chutes. If emergency escape chutes are built into the platforms could even make for an instant escape system before fire services arrive.

With these relatively straightforward enhancements, this evacuation system would be even better and would allow many people to escape who otherwise wouldn’t. OK, here’s a badly drawn pic: