Carbon Nanotubes Could Soon Replace Silicon In Electronic Devices

Carbon nanotube research has finally had a breakthrough that may allow production of microprocessors that are at least twice as fast as their silicon counterparts. According to Motherboard, nanotechnologists at the University of Wisconsin have developed a nanotube transistor that rivals silicon-based transistors in speed and efficiency. The technology could lead to devices which not only process data faster but also use less electricity, which would extend battery life.

Associate professor of materials science and engineering Michael Arnold expressed his excitement over the development.

“Making carbon nanotube transistors that are better than silicon transistors is a big milestone. This achievement has been a dream of nanotechnology for the last 20 years.”

Researchers in the field have known for quite some time that carbon nanotubes make better conductors than anything else so far discovered. The structures are only one atom thick, making them a perfect conduit for small scale electronics such as transistors in a microchip. However, carbon nanotubes have been difficult to create in a form pure enough for such applications.

Previous attempts to isolate nanotubes have fallen short due to small metallic impurities, which hindered the material’s semiconducting potential. One could think of it like a coffee straw that has hardened sugar crystals coating the inside. Sipping through the straw would still allow coffee through, but a clear straw would obviously be much better.

After decades of research, scientists have developed a technique to produce carbon nanotubes that are 99.99 percent pure. Falling back on the coffee straw analogy, this means that straws that had once had 10,000 sugar crystals, now only have one. This development is significant.

Researchers created and tested a transistor constructed of the material and discovered that it “was able to achieve a current that was 1.9 times higher than the most state-of-the-art silicon transistors in use today.”

The technique used to create the nearly pure carbon nanotubes is called “floating evaporative self-assembly.” The procedure, developed in 2014, was published in the peer-reviewed scientific journal, Langmuir.

According to Motherboard, “This technique works by leveraging the self-assembling properties of carbon nanotubes in a polymer solution, which also allows the researchers to manipulate the proper spacing of the ultrapure nanotubes on a wafer.”

While the study’s yield is a transistor nearly twice as efficient as contemporary components, a much greater efficiency is possible.

“Based on what is known about carbon nanotubes today, the researchers estimate that future transistors which make use of this nanotechnology should be able perform [sic] five times faster and use five times less energy than their silicon equivalents,” states Motherboard.

This advancement is also opening the door for the extension of Moore’s Law. In 1965, Intel’s co-founder, Gordon Moore, observed that the number of transistors on an integrated circuit had doubled every year since the IC was invented. He predicted that this would continue indefinitely. Once miniaturization took off, Moore’s Law was altered slightly to state that every 18 months processing speed and storage capacity would double.

This axiom held true for decades. However, Moore’s Law has been stumbling for the last several years because transistors have gotten almost as small as they can physically get. According to Inhabitat, computer scientists at IBM have already developed storage devices on the atomic scale. Also, chip manufacturers have abandoned trying to fit more transistors on an integrated circuit and instead just cram more ICs into their chipsets. For example, PC Advisor reports that Intel’s Core i7 Extreme has 12 physical cores on the chip.

“The recently released 2015 International Technology Roadmap for Semiconductors has predicted that the transistor would stop shrinking in just five years, by 2021,” Futurism states.

In essence, processors are to the point where they are growing in physical size to keep up with Moore’s Law and have been for some time. As carbon nanotube technology becomes more refined and less expensive, chipsets can again shrink in physical size, while still increasing performance.

The need to improve the cost-effectiveness and practicality of carbon nanotubes is unquestionable, but the technology also needs to be embraced if there is any chance for it to be utilized. Arnold expresses a need to change the negative view that the industry has developed over the last 20 years toward the technology.

“There has been a lot of hype about carbon nanotubes that hasn’t been realized, and that has kind of soured many people’s outlook. But we think the hype is deserved. It has just taken decades of work for the materials science to catch up and allow us to effectively harness these materials.”

Development in the field has been slower than the techniques currently employed by chip makers, so it has become regarded as too much talk and too little action. Without buy-in from the industry, carbon nanotube advancement will continue to be slow. Researchers will have to campaign for a change in perception of the technology if it is to become the next advancement in the computing industry.

[Image via University of Wisconsin, Madison]