Burn Pictures On A CD-R, No Special Drive Needed

When we routinely carry devices holding tens or hundreds of gigabytes of data, it’s sometimes a shock to remember that there was once a time when 650 MB on a CD was a very big deal indeed. These now archaic storage media came first as silver pre-recorded CD-ROMs, then later as recordable CD-Rs. Most people eventually owned CD writer drives, and some fancy ones came with the feature of etching pictures in the unused portions of the disc.

Haven’t got a fancy drive and desire an etched CD-R? No worries, [arduinocelentano] has a solution, in software which writes a disk image for a standard CD writer whose data makes the visible image on the disc.

CD-Rs have a thin layer of phthalate dye sandwiched between the polycarbonate disc and a silvered layer of lacquer. They’re often gold coloured, but the silvering is in fact just aluminium. The data is encoded as a series of pits and lands crested by the laser vapourising small portions of the dye to make holes.

The code creates a data structure of a standard CD-ROM session which doesn’t contain any usable data, instead whose pits and lands are arranged to form the image. You can find it all in a GitHub repository, and have a go at creating your own offerings. We would have made a Wrencher disc for our pictures, but sadly for some of us who were once in the thick of it we don’t have any CD-Rs any more.

Laser Etching Graphene Supercapacitors

The tech is nothing new, but did you know you can make your own graphene using your DVD burner? No seriously — all you need is a light-scribe compatible DVD burner and some graphite oxide.

It’s pretty simple. By placing a thin film on top of a DVD (or any plastic CD shaped disc), and coating it with graphite oxide, you can literally print patterns of graphene using the laser in your DVD burner. By making the shapes shown above, you can introduce an electrolyte and turn the whole thing into a supercapacitor. Albeit, a tiny super capacitor. But — you can print hundreds of them on a DVD in less than an hour.

We’ve covered this before a few times now, but that doesn’t make it any less interesting. We’re still waiting for someone (one of you guys!) to do a project that actually makes use of graphene! Hurry up!

[Thanks for the tip John!]