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Comment by ratsbane | Hacker News Reader

Am I the only one to think "hey, I could try this at home?" 1) prepare carbon slurry 2) pour on dvd 3) etch with LightScribe DVD drive... 4) Peel of graphene layer ...?

I wonder what, exactly, goes into the carbon slurry and if it's necessary to etch a particular pattern with the LightScribe.

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The professors who found this actually wrote a paper [1] explaining every step that they did to create their supercapacitor, including the formula for the gel-like electrolyte they used. The biggest problem I've found to making this at home is getting graphite oxide. They are expensive on the net (google it, not linking any store because I don't know any trustworthy), or hard to make (the usual method requires strong oxiders like sulfuric acid) [2]. There is a bottom-up approach to making them, that uses glucose [3], but I have no idea how hard it is, I need help from someone more knowledgeable in Chemistry before I try it. So if you want to really try this out, read those papers.

[1] http://www.sciencemag.org/content/335/6074/1326.abstract [2] https://en.wikipedia.org/wiki/Graphene_oxide [3] http://pubs.rsc.org/en/Content/ArticleLanding/2012/JM/c2jm15...

I thought so too but the result would be a CD with grey stuff on it.

My plan is to sell Lightscribe DVD drives and graphite oxide, like the store that sold shovels to gold miners.

I wondered about the etching process too. It might not be at all like a normal R/W pattern for a DVD. They could conceivably be scanning radially, or using a very slow revolution, or (is this possible?) re-tuning the beam's frequency. Not insurmountable, but might require low-level re-writing of the driver, depending.

>(is this possible?) re-tuning the beam's frequency.

No. DVD burners simply use a 630nm or 650nm red laser diode. It can not be re-tuned more than a few nm, by regulating the temperature of the diode.

You could replace the diode, but that is more effort than it's worth, and there's not much else to replace it with. If you wanted more power you might use a different diode, but the diodes are almost always buried really far in there and you would have to replace the electronics as well.

or just rig your own device and grab the high powered laser off of a blue ray player and slowly pull it to the outer edge. Seems a whole lot easier than having to deal with it messing up a drive within a computer.

I'm right there with you. I've been looking around to see more details on the process. Besides getting ahold of the materials, i think the most difficult part would be taking a graphene sheet and actually making it a supercapacitor. I think it requires layering it between some sort of electrolyte sheets right?

The supercapacitor they created is planar, you don't need to layer multiple sheets, you just need to print it then deposit the gel-like electrolyte and put it together with some copper tape and klapton tape. It's written/explained in their paper: http://www.sciencemag.org/content/335/6074/1326.abstract

Yes, sounds right. Quoting from the paper cited above "Thus, a device can be readily made by sandwiching an ion porous separator [Celgard 3501 (Celgard, Charlotte, NC)] between two identical LSG electrodes."

But the gel seperator they used was the standard industrial seperator gel for sCaps...there was a video on this, but it's too late tonight, i'll look for it tomorrow.

You don't even need the DVD burner - you can use sticky tape[1] (to make graphene anyway). That is actually how it was discovered[2], and that was worth a Nobel prize.

[1] http://www.scientificamerican.com/slideshow.cfm?id=diy-graph...

[2] http://www.independent.co.uk/news/science/the-graphene-story...

You have no control of the layer thickness through this process, and their supercapacitor design actually uses the graphite oxide that isn't turned into graphite as an insulator between the graphene sheets (their supercapacitor is planar, it does not use multiple layers). So no, while you can get graphene from a pencil and sticky tape, that's useless for this application.

After reading several papers on this I think that the hardest issue would depositing the GO and electrolytic layers on a CD substrate. Although there are some fairly reliable and not terribly difficult methods I doubt many would have the materials at home. I would love to try this but I'm a poor student. I may see if I can locate some GO onthe chem labs this summer when no ones around.

Their paper [1] show that it is actually quite simple, glue a PET layer to the CD, then deposit graphite oxide solution and let it dry overnight, to then put it in the lightscribe drive. They also explain how the supercapacitor is built with the electrolyte and how to make the electrolyte yourself, the hardest part from what I've read is actually getting graphite oxide.

[1] http://www.sciencemag.org/content/335/6074/1326.abstract

It's graphene, especially tiny bits of it, a bit of a biohazard also? (Think asbestos)

I've never heard of any health risks. People seem to handle graphite pencils ok (OTOH, coal dust isn't exactly the best thing in the world for you, but it is hardly asbestos)

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