banner by Rohit Maudgal
Tiny Tubes, Endless Possibilities
by Austin Kuntz
Cities are built on the strength of steel. For example, tTelephone wires connect people across the world using the conductivity of copper, and lightweight aluminum alloys make it possible for large commercial aircrafts to take to the skies.. Large commercial aircraft take to the skies due to lightweight aluminum alloys. Carbon nanotubes, or CNTs for short, have are 100 to 200 times the strength of stronger than steel, outperform copper in conducting heat and electricity , and are half as light as aluminum. Despite their incredible properties of the substance, CNTs they cannot replace classic materials in every aspect. One reason is because CNTs are extremely small, thereforeand they cannot effectively bond together to the size of something like a steel beam. Even with this limitation, CNTs have an extremely wide set of functions due to their structure. The material is comprisosed entirely of bonded carbon atoms that are bonded together in , arranged in connectingan arrangement of connected hexagons, much like the pattern of a chicken wire fence. Now imagine rolling that chicken wire fence up into the cylinder pattern in which you would find it packaged at the hardware store. The diameter of a CNT, though, is a billion times smaller than the rolled up chicken wireis, ranging from one to 50fifty nanometers, which is about 10,000 times thinner than a human hair.
Recent developments involving CNTs show a promising trend for the future of the nanomaterials industry. In 2015, the market size for CNTs was $1.35 billion, but by 2024 that number is projected to skyrocket to $8.1 billion. This explosive growth rate is due to recent novel applications of this material to medical imaging, computer science, material science and even space exploration. CNTs have seemingly limitless potential, which is just starting to be realized over two decades after their introduction to the scientific community in 1991.
A large part of the versatility of CNTs comes from their extremely small size. In the medical field, this size allows for implementationfor them to be implemented into devices that monitor the cellular level of the body at the cellular level. CNTs have been long used in medical imaging techniques, and a study at Pennsylvania State Universityrsity in State College, Pennsylvania, proposes that using CNT based technology may be the most effective way to detect viruses. While typical viral isolation usually requires some antibody or molecular tag, new devices that use CNT can separate viruses from a sample due to their advantageous size, rather than their chemical properties. Since CNTs are extremely thin and porous, the material acts like a filter that isolates the virus even when there is only a small concentration of a virus in the sample. By altering the distance between the CNTs in the device, differently sized viruses can be removed and subsequently studied. Trapping these viruses is especially important for the identification of new viruses to research new treatments. With this revolutionary method, emerging viral strains can be identified more quickly to respond to an epidemic before they exist on a large scale.
Furthermore, CNT based transistors now outperform the most commonly used silicon transistors. Transistors are electrically conductive switches that give a computer its processing power; the more transistors on a chip in a computer, the faster it will run. Silicon transistors have been almost completely optimized, so for computers to increase in processing power, another method needs to be considered to improve future central processing units. In September of 2016, a team at the University of Wisconsin-Madison posed a possible solution to this problem when they found that CNT based transistors perform five times faster than silicon transistors and use five times less energy. The small size and electrical conductivity of CNTs make them a possible candidate for the expansion of computing technology.
Along the avenue of material science, CNTs have uses on a macroscopic scale as well. A discovery involving CNTs and silkworms paves the way for new possibilities in wearable electronics and medical implants. In September of 2016, researchers at Tsinghua University in Beijing, China strengthened silk with CNTs more effectively than with traditional chemical methods. Silkworms were fed CNTs and graphene, which is the material folded to create CNTs, and the researchers found that not only was the silk able to withstand 50 percent more force before breaking, but it could conduct electricity as well.
Another application of CNT in materials science is Vantablack coating, which is created with vertically aligned CNTs and functions as a coating that can absorb an incredible amount of light. The material was developed in 2012; since 2014 it has been used in observational satellites. Space observation technology needs a reference point that is as dark as possible, and CNTs are capable of producing dark environments. In one square centimeter of the material used for this technology, there are one billion CNTs, allowing it to easily trap light. It absorbs 99.965 percent of visible light, and the spray-on form, developed in March of 2016, absorbs 99.8 percent of light.
The uses for a material this dark are mainly limited to imaging technology, such as telescopes and infrared sensors because it can block outside light from interfering with the technology. The material is also interesting, though, for its aesthetic appeal because of how dark it is. Its level of light absorption is so high that if a crumpled piece of aluminum foil was coated with Vantablack, the folds would not be visible, and only the two-dimensional shape would be observed. Due to this property, Vantablack has artistic applications as well, allowing any object to appear as a silhouette when coated with the substance.
CNTs have optimized devices in numerous fields on Earth and beyond. It is important to keep in mind, though, that many of these developments are recent, so use of this material has not expanded from research settings in many cases. On the other hand, it is also vital to see the possibilities inherent in the application of CNTs. In 2016, CNTs have shown the ability to detect new viruses, process information faster than in our current computers and create electronic clothing. The variability of CNTs means it could replace many classic materials once they are put to the test in more scientific environments. With CNTs overtaking other materials in so many fields, it leaves the question: what can’t these tubes do?