I shall have a look - good find!

Interesting

I am now convinced that our "civilisation" will experience an extraordinary revolution in a few years.

3D printing combined with Graphene technology is going to be HUGE! In about 10 - 20 years.

Imagine being able to print your own PV panels, not like todays panels, but thin film at 20 to 40 percent efficiency

At the moment these machines print with a range of raw materials. But what Im imagining is when we can print with graphene, this will be a killer technology. Read a bit about graphene and it becomes clear its a remarkable material that could be used across the board.


http://www.zdnet.com/the-10-strangest-facts-about-graphene-3040093050/

"But what is it that makes this material so remarkable? Here are 10 of the strangest facts about graphene.

1. Strength
"The most amazing thing to me about graphene is its strength. This is a sheet of atoms that you can pick up. That blows my mind."

So says Professor James (Jim) Tour of Rice University in Texas, and who are we to argue with that? A sheet of atoms that you can pick up: say it out loud to yourself a couple of times.

Everyone you ask about graphene's amazing properties says the same thing: it is really hard to pick one feature when the material is so astonishing. So let's consider a few more of them.

2. No band gap
Graphene has no band gap. A band gap is the gap between the energy of an electron when it is bound to an atom, and the so-called conduction band, where it is free to move around. An electron can't have an energy level between those two states.
This makes graphene a wonderful candidate for use in photovoltaic (PV) cells, for instance, because it can absorb photons with energy at every frequency — photons of different frequencies of light are converted to electrons with matching energy levels. A material with a band gap can't convert wavelengths of light that correspond to the forbidden energy states of the electrons. No band gap means everything is accepted.

This opens the tantalising possibility of highly efficient PV cells, but it's a problem if you want to use graphene in transistors, where you need the band gap to provide the isolation necessary if you want it to act as a switch that can be turned off.

It is possible to induce a small band gap in graphene by doping it. This is good enough for very fast amplifiers for radio work, but for transistors that make efficient logic circuitry you need a bigger gap.

3. Ballistic conduction
Yes, this is a really weird one: ambient temperature "unimpeded" conduction of electrons. It was observed in multi-walled carbon nanotubes at least as far back as 2002, and since graphene is basically an unzipped carbon nanotube, it does it too.
The hexagonal lattice has the longest "mean free path" of any known material — of the order of microns. This is the distance an electron can travel freely without bumping into anything, or having its path disrupted by scattering; the things that induce resistance. When the mean free path is longer than the dimensions of the material, you get ballistic transport.

In graphene, the mean free path is of the order of 65 microns — long enough that electronic components could be made that would operate at ambient temperatures with virtually no resistance. This is similar to superconductivity, but at room temperature.

4, 5 & 6. Best at electricity
And in case that doesn't impress you, Manchester University's Dr Leonid Ponomarenko points out that graphene also has "the highest current density (a million times that of copper) at room temperature; the highest intrinsic mobility (100 times more than in silicon); and conducts electricity in the limit of no electrons". Which means it can carry more electricity more efficiency, faster and with more precision than any other material.

7. Transparency
Back to Professor Tour for this one: "Another amazing thing about graphene is that you can see it. You can lay a sheet on a white piece of paper and actually see it. It is amazingly transparent, absorbing just 2.3 percent of light that lands on it, but if you have a blank sheet to compare it to, you can see that it is there." That means you can see a single layer of atoms with your naked eye, if they're graphene.
As well as making graphene even more useful as a potential solar cell component, its transparency makes it ideal for use in touchscreens. Currently most screens are made from Indium Tin Oxide (ITO), which absorbs 10 percent of incident light. But ITO is quite brittle, whereas graphene is extremely...

8 & 9. Elastic
Well, for a crystal, anyway. Graphene stretches up to 20 percent of its length. And yet it is also the stiffest known material — even stiffer than diamond.

10. Thermal conductivity
Graphene also beats diamond in thermal conductivity. In fact, graphene now holds the record for conducting heat — it's better than any other known material.

11. Impermeable
Here's one for luck. Graphene is also the most impermeable material ever discovered. "Even helium atoms cannot squeeze through," Dr Ponomarenko says. This makes it a great material for building highly sensitive gas detectors, for example, since even the smallest quantity of a gas will get caught in its lattice, changing its electrical properties.

All of the above makes graphene a good contender for yet another record: the material with the most records. For a substance that's only been closely studied since 2004, this makes it the child prodigy of material science, and one well worth the intense interest it continues to generate.

You print the high capacity graphene battery along with the inverter, PV panels etc etc

Are they still having trouble making it consistently and without contaminants.

I like 3D printing, used to do it in the 90's, was sticky resin and a laser then, sintering metal powder and a larger laser sounds fun.

Posted By: bot de paille
3D printing combined with Graphene technology is going to be HUGE! In about 10 - 20 years.

Er, I wouldn't hold your breath. The melting temperature of graphene is something like 4900K, which is one of the highest known. So whatever your 3D printer is made of would melt a long, long time before the graphene did.

You might need to roll it a bit flatter with a rolling pin.

Posted By: Seret

Posted By: bot de paille
3D printing combined with Graphene technology is going to be HUGE! In about 10 - 20 years.

Er, I wouldn't hold your breath. The melting temperature of graphene is something like 4900K, which is one of the highest known. So whatever your 3D printer is made of would melt a long, long time before the graphene did.

No, not true. Graphene has already been printed with a modified Epson Sylus printer. A normal DVD player has also been used with a DVD was dusted with graphite oxide, creating a layer of Graphene.

http://www.3ders.org/articles/20111128-first-printed-graphene-electronics.html

"Recently, Andrea Ferrari and peers at the University of Cambridge in the UK have managed to solve this problem and demonstrated a giant leap forward. By using a modified Epson Stylus 1500 Ink-jet printer and some customised cartridges, they have printed out onto a Silicon based substrate.

They peel graphene layers off with ultrasound (in jargon: sonication) from a graphite block and filter them so that the largest pieces are no longer clogging the printer head. Then they solve the flakes in the solvent N-methylpyrrolidone, or NMP, which counteracts the infamous coffee ring effect(In physics, a coffee ring is a pattern left by a puddle of particle-laden liquid after it evaporates). The ink is accumulated on the edge by this coffee ring effect. Another nice feature is that NMP is not very toxic. The last step was to place the NMP with dissolved grafeenvlokken in a printhead. The researchers printed a number of circuits and thin film transistors.

http://www.rsc.org/chemistryworld/News/2012/March/graphene-dvd-player-burn-supercapacitor.asp

Posted By: bot de paille
No, not true. Graphene has already been printed with a modified Epson Sylus printer.

Right I get you. So you're not actually talking about AM using graphene itself then. I still think your 10-20 year time frame from the price of graphene to become affordable enough to see widespread use is pretty quick. It's a pretty exotic material.

Additive Manufacturing. Generic catchall name that covers the bargain bin RepRap style extrusion printing, as well as more techy stuff like Selective Laser Sintering, stereolithography, etc.

It certainly sounds promising , In fact I'd say I even find it quite exciting . Lots more in this Graphene than I realised.

Love to see the Spring 2033 Screwfix catalogue if all this comes true.

I find it interesting that this thread started with an effort to point us in the direction of empowering intermediate technologies directly accessible to ordinary people and communities, using locally available renewable resources, and now we've all got carried away with something that seems inevitably to end up being exploited at the hands of the military-industrial complex and all its corporate interests for massive profits, with all the implications that brings.

Wouldn't it be nice, for example, to know how to make effective, easy-to-use building sealants out of cheap, abundant and locally available feedstocks. That's the sort of stuff I'd like to know about...

Posted By: Peter ClarkWhen the oil is going or gone we won't need Graphene, we will need locally produced and minimally processed insulation materials, building materials, food... well everything really.

Yes, up to a point - we will need locally produced and minimally processed bulk stuff. Also, I think we'll need to do a lot less travelling.

However, I really don't think there's a need to give up on high tech stuff. There will be a need to do it very differently and much less wastefully, not assuming that gadgets will be obsolete and thrown away before the end of the battery life and so on.

If we assume that the end of fossil fuels means the end of a large proportion of the population having access to a huge amount of information, entertainment, communication, and so on and don't make an effort to think ahead and work out how alternatives can work then it'll become a self-fulling prophecy.

There seems to be a mindset that it's a choice between a fossil-fuel business-as-usual society or some rather dour and drab survival. Maybe it is but it seems silly not look for other solutions first.

As to the graphene. Fine, interesting. Glad people are working on it. But it's still vapourware.

Posted By: Ed DaviesThere seems to be a mindset that it's a choice between a fossil-fuel business-as-usual society or some rather dour and drab survival. Maybe it is but it seems silly not look for other solutions first.

I certainly try hard, consciously, not to subscribe to this 'simple choice' mindset.

The thread was about low tech DIY, I understand that as meaning finding a way to do things less wastefully.

In my mind low tech does not match dour and drab, but hi tech often seems to.

The challenge might be to keep the best of traditional low tech and combine with the best of modern hi tech, but in a way that is practical when fossil fuels, and all that depends upon them, are in short supply.

How do you envisage things working in a way that is not extremely low tech when we have no fossil fuels?

Peter