Graphene is a widely known two-dimensional carbon allotrope that is as versatile as any material found on Earth. Its amazing properties as the lightest and strongest material, compared to its ability to conduct heat and electricity better than anything else, means that it can be integrated into a huge number of applications. Initially this means that graphene is used to help improve the performance and efficiency of current materials and substances, but in the future it will also be developed with other two-dimensional (2 d) crystals to create some even more amazing compounds that can be adapted to a wider range of applications. To understand the potential applications of graphene, it is first necessary to understand the basic properties of the material.
The first time graphene was synthesized; scientists literally dissected a piece of graphite, layer by layer, until only one layer remained. This process is known as mechanical exfoliation. The resulting graphite monolayer (called graphene) is only 1 atom thick, making it the thinnest material that does not become unstable when it is open to the elements (temperature, air, etc.). Because graphene is only one atom thick, other materials can be created by anachronistically inserting layers of graphene with other compounds (e.g., one layer of graphene, one layer of another compound, followed by another layer of graphene, etc.), effectively using graphene as an atomic scaffolding for the design of other materials. These newly created compounds may also be top materials, like graphene, but may have more applications.
Not surprisingly, after the development of graphene and the discovery of its special properties, interest in other 2D crystals has increased greatly. These other 2D crystals (e.g., boron nitride, niobium dienophthalate, and tantalum sulfide) can be used in combination with other 2D crystals, and the range of applications is virtually limitless. So, for example, if you use composite magnesium diboride (MgB2), which is considered a relatively efficient superconductor, and then add a separate graphene layer to its alternating atomic layer of magnesium boron, its efficiency as a superconductor increases. Or, another example is in the combination of the mineral pyromolybdenite (supervisor), which can be used as a semiconductor, with a graphene layer (graphene is a wonderful conductor) in the creation of NAND flash memories, developing flash memories much smaller and more flexible than the existing technology, (as to a group of researchers who have demonstrated at the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland).
The only problem with graphene is that high-quality graphene is a great conductor with no bandgap (can not be closed). Therefore, in order to use graphene in future nanoelectronic devices, a bandgap needs to be engineered into graphene that will reduce its electron mobility to the levels currently seen in strained silicon films. This essentially means that future research and development will be needed so that graphene replaces silicon in the future for use in power systems. However, several recent research groups have shown that this is not only possible, but probable, and we are looking at months, not years, until this is realized at least at a basic level. Some say this type of research should be avoided because it is similar to turning graphene into something it is not.
In any case, these two examples are just the tip of the iceberg in an area of research where graphene is a material that can be used in many disciplines, including, but not limited to: bioengineering, composites, energy technology, and nanotechnology.
Bioengineering will certainly be an area where graphene will be an important part of the future; although there are some hurdles to overcome before it can be used. Current estimates suggest that it won't be until 2030 when we'll start to see graphene widely used in biological applications as we still need to understand its biocompatibility (and it has to go through a lot of safety, clinical trials, and regulation, which, simply put, will take a long time). However, the properties it displays suggest that it could revolutionize the field in many ways. With its large surface area, high conductivity, thinness and strength, graphene would be a good candidate for the development of fast and efficient bioelectrical sensing devices capable of monitoring glucose levels, hemoglobin levels, cholesterol and even DNA sequencing. Eventually, we may even see engineered "toxic" graphene, which could be used as an antibiotic or even an anti-cancer treatment. In addition, because of its molecular composition and potential biocompatibility, it could be used in tissue regeneration processes.
One particular area where we will soon start to see graphene used on a commercial scale is in the field of optoelectronics; specifically touchscreens, liquid crystal displays (LCDs), and organic light-emitting diodes (oled). For the material to be used in optoelectronic applications, it must be able to transmit more than 90% of the light and also provide electronic conductivity in excess of 1 x 106Ω1m1 and therefore low resistance. Graphene is an almost completely transparent material capable of optically transmitting up to 97.7% of light. As we mentioned before, it is also highly conductive, making it great for optoelectronic applications such as LCD touchscreens in smartphones, tablets, desktop computers and TVs.
The most widely used material today is indium tin oxide (ITO), and the development of ITO manufacturing technology over the past few decades has allowed ITO materials to be well suited for this application. However, recent tests have shown that graphene has the potential to match the performance of ITO, even in its current (relatively undeveloped) state. In addition, recent studies have shown that the optical absorption of graphene can be altered by tuning the Fermi energy levels. Although this does not sound like a great improvement over ITO, graphene shows additional properties and by replacing ITO with graphene, very clever technologies could be developed in the field of optoelectronics. The fact that high-quality graphene has high tensile strength and flexibility (with a bending radius of less than the 5-10mm required for rollable e-paper) makes it almost inevitable that it will soon be used for these applications.
In terms of potential real-world electronic applications, we can eventually expect to see devices such as graphene-based e-paper capable of displaying interactive and updatable information, as well as flexible electronic devices including portable computers and TVs.
"Graphene is a material that can be used in a wide range of disciplines including, but not limited to: bioengineering, composites, energy technology, and nanotechnology."
Another outstanding property of graphene is that while it allows water to pass through it, it is almost completely immune to liquids and gases (even the relatively small helium molecule). This means that graphene can be used as an ultrafiltration medium, acting as a barrier between two substances. The advantage of using graphene is that it is only 1 single atom thick and can also be developed as a barrier to electronically measure strain and pressure (among many other variables) between 2 substances. A group of researchers at Columbia University managed to create single-layer graphene filters with pore sizes as small as 5 nm (currently, advanced nanoporous membranes have pore sizes of 30-40 nm). Although these pore sizes are very small, the pressure during the ultrafiltration process is reduced because the graphene is very thin. Jointly currently, graphene is much stronger and less fragile than aluminum oxide (currently used in filtration applications below 100nm). What does this mean? Well, it could mean that graphene is being developed for water filtration systems, desalination systems, and efficient and more economically viable biofuel creation.
Graphene is strong, tough, and very light. Aerospace engineers are currently incorporating carbon fiber into the production of aircraft because it is also very strong and lightweight. However, graphene is stronger and also lighter. Eventually, graphene is expected to be utilized (possibly integrated into plastics, such as epoxy) to create a material that can replace steel in aircraft structures, improving fuel efficiency, range and weight reduction. Due to its electrical conductivity, it could even be used to coat aircraft surface materials to prevent electrical damage from lightning strikes. In the example, the same graphene coating could also be used to measure strain rates, notifying pilots of any changes in the stress levels at which an airplane wing is subjected.
Providing very low levels of light absorption (around 2.7% of white light) while also providing high electron mobility means that graphene can be used as an alternative to silicon or ITO in the manufacture of photovoltaic cells. Silicon is currently widely used in the production of photovoltaic cells, but while silicon cells are very expensive to produce, graphene-based cells are likely to be much less so. When a material such as silicon converts light into electricity, it produces photons for each electron produced, meaning that much of the potential energy is lost to heat. Recently published research has demonstrated that when graphene absorbs a photon, it actually produces multiple electrons. Additionally, while silicon is able to generate electricity from certain wavelengths of the light band, graphene is able to operate at all wavelengths, meaning that graphene has the potential to be just as efficient as silicon, ITO, or (also widely used) gallium arsenide. Being flexible and thin means that graphene-based photovoltaic cells can be used in clothing; to help charge cell phones, or even used as vintage photovoltaic windows or curtains to power homes.
One area of research that is highly investigated is energy storage. While all areas of electronics have been evolving at a very fast pace over the last few decades (refer to Moore's Law, which states that the number of transistors used in electronic circuits will double every two years), the problem has always been storing energy when not in use, please use batteries and capacitors. These energy storage solutions are much slower to develop. The problem is that batteries may take up a lot of energy but can take a long time to recharge, on the other hand, capacitors can be recharged very quickly but do not hold as much energy (relatively speaking) ).
Currently, scientists are working on improving the performance of lithium-ion batteries (by using graphene as an anode) to provide higher storage capacity with better lifetime and charging rates. In addition, graphene is being researched and developed for use in the manufacture of supercapacitors, which are capable of charging very quickly and can also store large amounts of electricity. Graphene-based micro-supercapacitors may be developed for low-energy applications such as smart phones and portable computing devices, and may be commercially available within the next 5 to 10 years. Graphene-enhanced lithium-ion batteries could be used in higher-energy applications, such as electric vehicles, or they could be used as lithium-ion batteries in smartphones,
Article reprinted from Public:Graphene Radar