DIY graphene supercapacitor fabrication using a LightScribe DVDROM - Page 1
Forum section: electronics / general

author: cdev
author_rank: Super Contributor
timestamp: May 30, 2017, 12:04:07 am
content: This looks interesting.http://newsroom.ucla.edu/releases/ucla-researchers-develop-new-technique-243553______quoted text_____The new cost-effective fabrication method, described in a study published this week in the journal Nature Communications, holds promise for the mass production of these supercapacitors, which have the potential to transform electronics and other fields."The integration of energy-storage units with electronic circuits is challenging and often limits the miniaturization of the entire system," said Kaner, who is also a professor of materials science and engineering at UCLA's Henry Samueli School of Engineering and Applied Science. "This is because the necessary energy-storage components scale down poorly in size and are not well suited to the planar geometries of most integrated fabrication processes.""Traditional methods for the fabrication of micro-supercapacitors involve labor-intensive lithographic techniques that have proven difficult for building cost-effective devices, thus limiting their commercial application," El-Kady said. "Instead, we used a consumer-grade LightScribe DVD burner to produce graphene micro-supercapacitors over large areas at a fraction of the cost of traditional devices. Using this technique, we have been able to produce more than 100 micro-supercapacitors on a single disc in less than 30 minutes, using inexpensive materials."The process of miniaturization often relies on flattening technology, making devices thinner and more like a geometric plane that has only two dimensions. In developing their new micro-supercapacitor, Kaner and El-Kady used a two-dimensional sheet of carbon, known as graphene, which only has the thickness of a single atom in the third dimension.Kaner and El-Kady took advantage of a new structural design during the fabrication. For any supercapacitor to be effective, two separated electrodes have to be positioned so that the available surface area between them is maximized. This allows the supercapacitor to store a greater charge. A previous design stacked the layers of graphene serving as electrodes, like the slices of bread on a sandwich. While this design was functional, however, it was not compatible with integrated circuits.In their new design, the researchers placed the electrodes side by side using an interdigitated pattern, akin to interwoven fingers. This helped to maximize the accessible surface area available for each of the two electrodes while also reducing the path over which ions in the electrolyte would need to diffuse. As a result, the new supercapacitors have more charge capacity and rate capability than their stacked counterparts.Interestingly, the researchers found that by placing more electrodes per unit area, they boosted the micro-supercapacitor's ability to store even more charge.Kaner and El-Kady were able to fabricate these intricate supercapacitors using an affordable and scalable technique that they had developed earlier. They glued a layer of plastic onto the surface of a DVD and then coated the plastic with a layer of graphite oxide. Then, they simply inserted the coated disc into a commercially available LightScribe optical drive — traditionally used to label DVDs — and took advantage of the drive's own laser to create the interdigitated pattern. The laser scribing is so precise that none of the "interwoven fingers" touch each other, which would short-circuit the supercapacitor."To label discs using LightScribe, the surface of the disc is coated with a reactive dye that changes color on exposure to the laser light. Instead of printing on this specialized coating, our approach is to coat the disc with a film of graphite oxide, which then can be directly printed on," Kaner said. "We previously found an unusual photo-thermal effect in which graphite oxide absorbs the laser light and is converted into graphene in a similar fashion to the commercial LightScribe process. With the precision of the laser, the drive renders the computer-designed pattern onto the graphite oxide film to produce the desired graphene circuits.""The process is straightforward, cost-effective and can be done at home," El-Kady said. "One only needs a DVD burner and graphite oxide dispersion in water, which is commercially available at a moderate cost."The new micro-supercapacitors are also highly bendable and twistable, making them potentially useful as energy-storage devices in flexible electronics like roll-up displays and TVs, e-paper, and even wearable electronics.

author: Ampera
author_rank: Super Contributor
timestamp: May 30, 2017, 12:54:33 am
content: Hah, Lightscribe. I never had a drive that did that, but I think nobody else did either.

author: cdev
author_rank: Super Contributor
timestamp: May 30, 2017, 01:21:26 am
content: re:LightScribeYou can make very nicely labeled disks with them.Also, there are other applications. (makingencoder disksfor example)

author: Halcyon
author_rank: Unknown
timestamp: May 30, 2017, 01:32:51 am
content: Quote from: TwoOfFive on May 30, 2017, 12:54:33 amThey were more popular than you think, it's just not many people really took any notice. Many brand-name laptops shipped with Lightscribe compatible drives by default. You can still pick up current DVD/Blu ray burners on the market today that support writing of Lightscribe labels, even if they don't have the Lightscribe logo printed on the front of the drive (you need to check the specs).I think blank Lightscribe media is pretty much extinct these days not to mention even when they were available, they were expensive and the print quality was fairly poor by comparison to other printing techniques. Print speed was also comparatively slow.

author: Brumby
author_rank: Unknown
timestamp: May 30, 2017, 02:24:11 am
content: That encoder pattern looks neat - but you would never use that layout for a real encoder wheel.

author: cdev
author_rank: Super Contributor
timestamp: May 30, 2017, 03:07:40 am
content: It reminds me a lot of some Southwestern pottery designs.

author: noidea
author_rank: Unknown
timestamp: May 30, 2017, 05:22:49 am
content: Quote from: cdev on May 30, 2017, 03:07:40 amMore like the stroboscopic marks that used to be around the platter of old high end turntables so that you could check they were running at the correct RPM

author: CJay
author_rank: Super Contributor
timestamp: May 30, 2017, 06:55:30 am
content: Quote from: TwoOfFive on May 30, 2017, 12:54:33 amI've got three or four, possibly more here. There was a period where every HP machine that came with an optical writer had a Lightscribe capable drive so there are a *LOT* of them out there.I probably have some media too but the one time I used it, I was rather disappointed with the speed and results so went back to my marker pen.

author: Halcyon
author_rank: Unknown
timestamp: May 30, 2017, 08:50:51 am
content: Quote from: noidea on May 30, 2017, 05:22:49 amOr those printed on the motors on some 5.25" Floppy Disk Drives for adjustment.

author: CJay
author_rank: Super Contributor
timestamp: May 30, 2017, 09:32:33 am
content: Quote from: Halcyon on May 30, 2017, 08:50:51 amAh, fun times, those drives were good to work on and the speed controller boards combined with the motors made nice PCB drills, LM2917 frequency to voltage chips on a lot of them IIRC