A great deal is being written about graphene, in textiles and other industries. We talked to Vorbeck Materials Corp. President & CEO Dr. John Lettow to learn more about what many are characterizing as a miracle material.
In its press release, the committee stated: “Graphene is a thin flake of carbon, just one atom thick.…As a material it is completely new—not only the thinnest ever but also the strongest. As a conductor of electricity, it performs as well as copper. As a conductor of heat, it outperforms all other known materials. It is almost completely transparent, yet so dense that not even helium, the smallest gas atom, can pass through it. Carbon, the basis of all known life on earth, has surprised us once again.”
Kudos to Geim and Novoselov for receiving this prestigious award and the glowing description of the material from the Royal Swedish Academy of Sciences. But it should also be noted that beyond the great work at the University of Manchester, there is significant other work going on to leverage the value of this miracle material for new and innovative uses. We spoke with Dr. John Lettow, President & CEO of Vorbeck Materials Corp., whose company is also conducting groundbreaking graphene work.
WhatTheyThink: Dr. Lettow, when did you and the team begin working with graphene?
John Lettow: We started working with Princeton in the 2005–2006 timeframe, around the time the very first exciting papers about graphene were coming out, and well before the hype of the Nobel prize. Vorbeck derived its technology from research at Princeton—we license technology from them—and Princeton Professor Ilhan Askay is a co-founder of the company and a scientific advisor for us.
WTT: Can you describe graphene for us in layman’s terms?
JL: Graphene is derived from graphite, or related to graphite chemically. I use the analogy that graphite, which you might most commonly relate to as the material used in pencils, is like a ream of paper, where you have lots of carbon layers stacked up in crystallographic order. Graphene is the single sheet within that stack. When you are using graphite in a pencil, it is soft. As you write, chemically what happens is the layers within that ream of paper are sliding over each other and leaving a smudge. When you take the single sheet out, it is very strong, like a single sheet of paper, and has very different electrical and thermal properties, where the electrons move quickly and easily. It’s a very exceptional material.
WTT: How are you working with graphene? What are the application areas you are exploring?
JL: We are working in three different areas: batteries, inks, and coatings, and blending graphene with other materials to enhance not only electrical conductivity, but also the strength and electrical/thermal properties of those materials.
WTT: Can you give us examples of each?
JL: With batteries, graphene goes into the electrodes of the battery itself, the anode and cathode, or negative and positive electrodes. When you mix graphene into the electrode compositions, you get a material with a faster charge/recharge rate because of the electrical conductivity of graphene blended in with lithium-ion storage materials. You also get a longer lifetime—it can go through more cycles before it wears down.
WTT: Is this commercially available yet?
JL: It is not fully commercial yet; it is still in development, at least in our case. It is hard to predict when it will become commercially available because we are working through partners to productize it and are dependent on their technology insertion cycles. But I would expect batteries with graphene will begin to enter the market within the next year or two.
WTT: How about inks and coatings? What are some of the applications there?
JL: This is primarily for printed electronics. It an be used with inkjet, flexography, screen printing and offset. We do have products that are being utilized based on printed electronics with commercial customers and with the military. The benefit as opposed to other ways to create printed electronics is that previously, we were using carbon black or carbon particles which have lower conductivity, or silver particles.
Some of the advantages of using graphene versus those materials are that graphene as a carbon is much more conductive than other carbon-based conductive materials. Against silver inks, it is much more flexible and robust in the sense that you can take things printed with our graphene inks and boil them in salt water for hours and they don’t corrode. You can flex them thousands of times, and they don’t break or wear out. So versus carbon or metallics, our inks and coatings with graphene are more robust and flexible, and chemically inert so they don’t corrode, and they don’t have ill effects as a result of temperature. This makes them ideal for the wearable electronics environment where you have sweat, salt, water, rain, as well as real mechanical stresses. You need to be able to wash things. We have put our printed electronics through 50 complete wash and dry cycles with detergent without losing functionality. And they are a very thin coating. Going back to our paper analogy, if you are using graphene, and you print on a surface with binders and other things in your inks and coatings, it lays on the surface, like papier mâché with single sheets of paper. But when you use other particles, like carbon black, it’s like using papier mâché with whole reams of paper, and the bonding between the particles is not very good.
WTT: And when you combine graphene with other materials, what are some examples there?
JL: In this case, you are blending the graphene sheets with other materials such as polymers, plastics or rubber, and you are strengthening the material. Rubber for tires is a good example here. It not only enhances the strength and thermal stability of the tire, but it improves the rolling resistance. When driving, you lose as much energy through the rolling resistance of your tires as you do through aerodynamics—wind resistance. This becomes an important factor in fuel efficiency for vehicles and can make tires last longer. While this is not commercially available for tires yet, we do have a collaboration with Reliance Industries of India, one of the largest synthetic rubber producers in the world, and we are working on scaling commercialization with partners like Reliance.
WTT: I understand you are also working with AFFOA on fiber computing. How does graphene fit in there?
JL: With graphene being one of the strongest materials known, it enhances mechanical properties. There are two ways we use graphene with fibers. You can blend it into the fiber itself and then spin it. Because graphene sheets are so thin and flexible, you can spin and draw the fiber to a much greater degree, while with normal particles, you would introduce flaws into the fiber as you spin and draw it. The other way is as a coating or sizing. Just like our other coatings, graphene sheets are wrapped around the fiber itself, creating a conductive layer or introducing thermal properties.
One of the things we are looking at with other AFFOA members as a commercial area is incorporating the graphene electronics into wearables and clothing to create an electronics ecosystem within the apparel, like graphene-based touch pads that you can incorporate into the sleeves of a garment to control devices, all the way through to safety sensors, indicators, and biometric type devices. For example, workers who are remote or lone workers could have apparel that would alert them to a dangerous situation such as presence of hazardous gas.
WTT: This is an exciting area, and we appreciate you helping our members understand it in more of layman’s terms. Any closing thoughts?
JL: It is an exciting area. You don’t have to look to far out into the future to imagine that almost everything that is done in hard devices in cases right now will be migrating into more flexible, softer formats, and into clothing itself, with the exception, perhaps, of the screen, which could be accessed through augmented reality glasses or some other means. It’s also interesting to note that one of the fastest growing areas is in voice interaction, voice control, and touch control, and those can be integrated into clothing with some of the technology that is being developed right now. One of the things I love about it, and that I think will be a huge benefit of this type of technology, is that we will have it with us and accessible to us but not have it be something we have to take out and focus on all the time, ignoring other things in the world around us. I like to think about flexible and apparel-based electronics as something that will be present and accessible all of the time, but not with the same level of constant distraction and demand for attention that our screens are today.