Graphene Goes to Market
 
As we’ve explained in previous issues of Trends, graphene is truly a “wonder material” that is made from a single layer of carbon atoms in the shape of a honeycomb. It was isolated from graphite in 2004 by University of Manchester scientists Andre Geim and Kostya Novoselov, who won the 2010 Nobel Prize in Physics for their game-changing discovery.

Graphene offers a remarkable combination of properties:

- It is the strongest known material, at 200 times the strength of steel.

- It is harder than diamond.

- It is the thinnest substance ever discovered, at one-millionth the width of a sheet of paper.

- It is extremely flexible and stretchable.

- It conducts both heat and electricity better than any other material.

- It is nearly transparent.

- It filters out nearly every type of liquid gas, while allowing water to flow through it.

Because of these properties, graphene offers the potential to revolutionize any number of industries?if it can be manufactured cost-effectively.

Fortunately, according to a research paper published in the journal Advanced Materials, scientists from the University of Exeter have discovered an innovative new technique that will make it easier and cheaper to produce graphene.1

The current production process for making graphene relies on an expensive, time-consuming method called chemical vapor deposition (CVD). The Exeter researchers created graphene in an industrial cold wall CVD system, called nanoCVD. This approach is based on a concept that is already used to make other products by semiconductor manufacturers.

What this means is that graphene could easily be mass-produced by semiconductor firms, using their current plants, instead of having to invest hundreds of millions of dollars to design and build new factories to make graphene. This approach will allow graphene to be made 100 times faster, while slashing the cost by 99 percent.

Along with other breakthroughs we’ve reported on in the past, this development is finally enabling scientists to feel confident that they’ll be able to take graphene out of the lab and into the real world.

For example, the Exeter researchers are using nanoCVD to develop the first transparent and flexible touch sensor. Taking advantage of graphene’s flexibility, the researchers believe they will be able to make electronic skin for robots that will make the machines move and appear more like humans.

What other applications are on the horizon? Please consider the following forecasts:

First, products based on graphene’s flexibility will transform the electronics industry, allowing wearable electronics to become ubiquitous.

According to Digital Trends, a company called FlexEnable recently demonstrated two prototypes at the 2016 Mobile World Congress in Barcelona: a curved LCD that can be wrapped around a user’s wrist, and a flexible fingerprint sensor that can be used as a security device on a phone or car door.2 Meanwhile, Nokia exhibited virtual reality gloves with flexible graphene sensors that can detect gestures and temperature changes. The Institute of Photonic Sciences displayed a flexible heart rate sensor that accurately records the user’s pulse when it is pressed with a finger; the sensor could be embedded in a FitBit or other wearable health-tracking devices. Smartphones made from graphene could even be folded a few times so they would fit more easily into a pocket or purse.
 
Second, it is possible that graphene may one day improve the economics of certain green technologies so that they will actually generate more energy than they consume.

Currently, because silicon releases only one electron for every photon that hits it, silicon-based solar cells achieve energy efficiency at a dismal rate of 25 percent, despite the massive government subsidies that fund solar startups. However, according to another Digital Trends report, graphene can release several electrons for each photon, so a solar cell made with graphene could potentially achieve energy efficiency of 60 percent.3

Third, graphene may provide a solution to the severe water shortages that afflict vast regions of the world.

Because graphene blocks nearly every liquid and gas except water, it could be used to filter out salt or sludge, enabling billions of people to enjoy access to clean drinking water that is beyond their reach today. Compared to the reverse osmosis process that is currently used in desalination plants, graphene filters would be faster, cheaper, and more energy-efficient. According to Lockheed Martin, which invented a graphene filter called Perforene, the new filter will use only 1 percent of the energy that reverse osmosis uses.
 
Fourth, a new technology that uses graphene could cut consumers’ costs for heat and hot water dramatically.

As recently reported in IEEE Spectrum, UK startup Xefro has developed a new system using graphene as a heating element.4 Xefro contends that its system will save users 25?70 percent on their heating and hot water costs, depending on the type of system that is replaced. According to the report, “Xefro uses graphene-based ink that can be printed on a variety of materials and into just about any configuration. The system takes advantage of graphene’s minimal thermal mass so the heat can be turned on and off quickly, and leverages graphene’s large surface area so that energy isn’t wasted in heating up the heater itself.” That allows the system to avoid the expensive inefficiencies that plague today’s heating systems?the multiple conversions of heat as gas is burned to heat water, which makes radiators hot, which in turn heat the air, which finally makes the room warm.
 
Fifth, graphene will transform DNA sequencing.

According to research published in the journal Nanoscale, a team from the National Institute of Standards and Technology (NIST) improved upon the current approach to sequencing, which entails dividing, copying, labeling, and reassembling pieces of DNA to read the genetic information.5 The NIST team simulated a new concept for faster gene sequencing by pulling a DNA molecule through a small hole in graphene and then detecting changes in electrical current. According to the team, the new technique could identify about 66 billion bases per second with 90 percent accuracy and no false positives. This would be faster and cheaper than conventional DNA sequencing, allowing for prompt processing of forensics evidence. Ultimately, this breakthrough could lead to the development of “DNA sensing devices” that would not depend on the advanced data processing, microscopes, or highly restricted operating conditions that would elevate their costs and limit their functionality in the real world today. Beyond that important application, the NIST researchers theorize that, based on the current accuracy rate of 90 percent, measuring the same DNA strand four times would yield the accuracy rate of 99.99 percent that is needed to sequence the human genome. That could lead to a new era of personalized medicine in which an individual’s unique genome would be used to predict, and then prevent or immediately treat, any medical condition that he or she is genetically predisposed to developing.
 
References
1. Advanced Materials, July 22, 2015, Vol. 27, Iss. 28, “High Quality Monolayer Graphene Synthesized by Resistive Heating Cold Wall Chemical Vapor Deposition,” by Thomas H. Bointon, Matthew D. Barnes, Saverio Russo, and Monica F. Cracin. ⓒ 2015 John Wiley & Sons, Inc. All rights reserved.

http://onlinelibrary.wiley.com/doi/10.1002/adma.201501600/full

2. Digital Trends, February 24, 2016, “5 Ways the ‘Supermaterial’ Graphene Could Transform the Tech Around Us,” by Simon Hill. ⓒ 2016 Designtechnica Corporation. All rights reserved.

http://www.digitaltrends.com/mobile/amazing-graphene-prototypes/

3. Digital Trends, October 17, 2015, “A Material Supreme: How Graphene Will Shape the World of Tomorrow,” by Will Nicol. ⓒ 2015 Designtechnica Corporation. All rights reserved.

http://www.digitaltrends.com/cool-tech/what-is-graphene-and-how-will-it-shape-the-future-of-tech/-ixzz41rcn0mfK

4. IEEE Spectrum, June 2, 2015, “Graphene Heating System Dramatically Reduces Home Energy Costs,” by Dexter Johnson. ⓒ 2015 IEEE Spectrum. All rights reserved.

http://spectrum.ieee.org/nanoclast/green-tech/conservation/graphene-heating-system-dramatically-reduces-home-energy-costs

5. Nanoscale, January 28, 2016, Iss. 4, “Nucleobase-Functionalized Graphene Nanoribbons for Accurate High-Speed DNA Sequencing,” by Eugene Paulechka, Tsijerk A. Wassenaar, Kenneth Kroenlein, Andrei Kazakov, and Alex Smolyanitsky. ⓒ 2016 Royal Society of Chemistry. All rights reserved.

http://pubs.rsc.org/en/Content/ArticleLanding/2016/NR/C5NR07061A-!divAbstract