graphene

43 Articles

Graphene Super Caps: Coming Soon?

December 10, 2015 by 29 Comments

If you read Hackaday regularly, you’ve probably heard that you can use a LASER to create graphene. There’s been a bit of research on how to make practical graphene supercapacitors using the technique (known as LIG or LASER-induced graphene). Researchers at Rice University have been working on this, and apparently they’ve had significant success inducing graphene capacitors on a Kapton substrate. The team has published a paper in Advanced Materials (which is behind a paywall) about their work.

In particular, Rice claims that they have easily produced supercapacitors with an energy density of 3.2 mW/cubic centimeter (that’s what the University’s website reports; they probably mean mW-hours/cubic centimeter) with capacitances near one millifarad per square centimeter. A key benefit of the construction method is that the capacitors continued to work after researchers bent them 10,000 times. A flexible capacitor is useful in wearable devices that would often flex, or in a device like a cell phone that could bend in your back pocket as you sit.

Continue reading “Graphene Super Caps: Coming Soon?” →

Self Folding Graphene Paper

November 13, 2015 by 2 Comments

Origami, the art of folding paper into shapes, is the latest craft to fall to automation. Researchers in China have published a paper in Science Advances describing how they created graphene-based paper that can fold itself. According to their paper (that is, the paper they wrote, not their graphene paper), the new material can adopt a predefined shape, walk, or even turn a corner.

Active materials like shape memory polymers, aren’t new. But there are many practical problems with using such materials. Using MGMs (Macroscopic Graphene Materials), the researchers created paper that can change shape based on light. temperature, or humidity.

The video below shows a few uses including a self-folding box, a worm-like motion device, and a hand-like piece of paper making a grasping motion. The creators mention that there are a wide range of applications including robotics, artificial muscles, and sensing devices. After watching the video, we couldn’t help but wonder how cool a paper flower that opened in the sunlight would be.

We’ve covered how to make your own graphene in a home lab and even inside a DVD burner. We’ll be interested to see who is the first to hack some graphene paper and what you’ll use it for.

Continue reading “Self Folding Graphene Paper” →

Rod Logic And Graphene: Elusive Molecule-Scale Computers

October 19, 2015 by 23 Comments

I collect slide rules. You probably know a slide rule is a mechanical calculator of sorts. They usually look like a ruler (hence the name) and have a sliding part (hence the name) and by using logarithms you can multiply and divide easily by doing number line addition and subtraction (among other things).

It is easy to dismiss old technology like that out of hand as being antiquated, but mechanical computing may be making a comeback. It may seem ancient, but mechanical adding machines, cash registers, and even weapon control computers were all mechanical devices a few decades ago and there were some pretty sophisticated techniques developed to make them work. Perhaps the most sophisticated of all was Babbage’s difference engine, even though he didn’t have the technology to make one that actually functioned (the Computer History Museum did though; you should see it operating in person, but this is good too).

Continue reading “Rod Logic And Graphene: Elusive Molecule-Scale Computers” →

Graphene Grown On Semiconductors Big Step Toward Manufacturability

October 14, 2015 by 11 Comments

No modern technology has been met with more hype than graphene. These single-layer sheets of carbon promise everything from incredibly efficient power grids to more advanced electronics to literal elevators to space. Until now, though, researchers have yet to produce graphene sheets or ribbons in a reliable way. Researchers at the University of Wisconsin at Madison and the US Department of Energy Argonne National Laboratory have done just that, growing graphene nanoribbons on the surface of a germanium crystal.

By using a germanium crystal as a substrate, the researchers have found a directionality to the way these graphene nanoribbons form. This has been a problem for researchers experimenting with graphene microelectronics in the past; labs experimenting with making transistors out of carbon nanotubes found growth is highly unpredictable. The controlled growth of graphene nanoribbons opens the door to more precise fabrication, something that is necessary for microelectronics fabrication.

Synthesis of nanoribbons this small have not been possible before. Because germanium itself is a semiconductor – and was used for the first transistor – this discovery may pave the way for the creation of graphene-based circuits grown using the same semiconductor fabrication processes used today.

Laser Etching Graphene Supercapacitors

October 3, 2015 by 24 Comments

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!]

Ask Hackaday: Graphene Capacitors On Kickstarter

July 26, 2014 by 140 Comments

Last week, we heard of an interesting Kickstarter that puts a capacitor and charging circuit in the same space as a AA battery. This is usually a very simple endeavour, but this capacitor has the same energy density as an alkaline cell. The chemistry inside this capacitor was initially attributed to lithium ion, and a few people in the comments section were wondering how this was possible. The math just didn’t seem to add up.

The guy behind this Kickstarter, [Shawn West], recently spilled the beans on these… interesting capacitors. Apparently, they’re not lithium ion capacitors at all, but graphene capacitors. Graphene capacitors you can buy. On Kickstarter. Graphene capacitors, also known as the thing that will change everything from smartphones to electric vehicles, and everything in between. I will admit I am skeptical of this Kickstarter.

Apparently, these graphene supercaps are in part designed and manufactured by [Shawn] himself. He fabricates the graphene by putting graphite powder in a ball mill for a day, adding a bit of water and surfactant, then running the ball mill for another few days. The graphene then floats to the top where it is skimmed off and applied to a nonconductive film.

There’s absolutely nothing that flies in the face of the laws of physics when it comes to graphene capacitors – we’ve seen a few researchers at UCLA figure out how to make a graphene supercap. The general consensus when it comes to graphene supercaps is something along the lines of, ‘yeah, it’ll be awesome, in 10 years or so.’ I don’t think anyone thought the first graphene capacitors would be available through Kickstarter, though.

I’m a little torn on this one. On one hand, graphene supercaps, now. On the other hand, graphene supercaps on Kickstarter. I’m not calling this a scam, but if [Shawn]’s caps are legit, you would think huge companies and governments would be breaking down his door to sign licensing agreements.

Post your thoughts below.

Synthesizing Graphene In Your Basement Laboratory

April 9, 2013 by 54 Comments

We’re surprised that we haven’t come across any of [Robert Murray-Smith’s] projects before. Looking through his collection of YouTube uploads proves that he’s a very active amateur chemist (we assume this is a hobby because he performs the experiment in a mayonnaise jar). The video we’re featuring today is about ten minutes of his technique for synthesizing graphene. The video can be watched after the break. Be warned that the audio doesn’t sync with the video because he overdubbed the presentation to fix up the poor audio quality from the original.

Graphene is something of a compound-du-jour when it comes to electronic research. You may remember reading about using DVD burners to make graphene film that will go into thinks like super-capacitors to replace batteries. [Robert] starts off his process with a jar of 98% sulfuric acid and 75% phosphoric acid. He pours in powdered graphite (chemical proportions are important here) and gives it a swirl. Next some potassium permanganate is added over about five or ten minutes. From there it goes on the stir plate for three days of constant stirring. During this time the solution will go from green to brown, indicating the presence of graphene oxide.

He goes on from there, but it’s clear he hasn’t found an iron-clad route to his end goal of isolating the graphene for use in constructing things like those super-capcitors we mentioned earlier. If you’ve got a home lab and some interest perhaps you can contribute to his efforts.

Continue reading “Synthesizing Graphene In Your Basement Laboratory” →