Move over, silicon. In a breakthrough in the quest for the next generation of computers and materials, researchers at USC have solved a longstanding challenge with carbon nanotubes: how to actually build them with specific, predictable atomic structures.
"We are solving a fundamental problem of the carbon nanotube," said Chongwu Zhou, professor in the Ming Hsieh Department of Electrical Engineering at the USC Viterbi School of Engineering and corresponding author of the study published August 23 in the journal Nano Letters. "To be able to control the atomic structure, or chirality, of nanotubes has basically been our dream, a dream in the nanotube field."
If this is an age built on silicon, then the next one may be built on carbon nanotubes, which have shown promise in everything from optics to energy storage to touch screens. Not only are nanotubes transparent, but this research discovery on how to control the atomic structure of nanotubes will pave the way for computers that are smaller, faster and more energy efficient than those reliant on silicon transistors.
"We are now working on scale up the process," Zhou said. "Our method can revoutionize the field and significantly push forward the real applications of nanotube in many fields."
Until now, scientists were unable to "grow" carbon nanotubes with specific attributes — say metallic rather than semiconducting — instead getting mixed, random batches and then sorting them. The sorting process also shortened the nanotubes significantly, making the material less practical for many applications.
For more than three years, the USC team has been working on the idea of using these short sorted nanotubes as "seeds" to grow longer nanotubes, extending them at high temperatures to get the desired atomic structure.
A paper last year by the same team in Nature Communications outlined the technique, and in the current Nano Letters paper, the researchers report on their latest major success: identifying the "growth recipes" for building carbon nanotubes with specific atomic structures.
"We identify the mechanisms required for mass amplification of nanotubes," said co-lead author Jia Liu, a doctoral student in chemistry at the USC Dornsife College of Letters, Arts and Sciences, recalling the moment when, alone in a dark room, she finally saw the spectral data supporting their method. "It was my Eureka moment."
"To understand nanotube growth behaviors allows us to produce larger amounts of nanotubes and better control that growth," she continued.
Each defined type of carbon nanotube has a frequency at which it expands and contracts. The researchers showed that the newly grown nanotubes had the same atomic structure by matching the Raman frequency.
"This is a very exciting field, and this was the most difficult problem," said co-lead author Bilu Liu, a postdoctoral research associate at the USC Viterbi School of Engineering. "I met Professor Zhou [senior author of the paper] at a conference and he said he wanted to tackle the challenge of controlling the atomic structure of nanotubes. That's what brought me to his lab, because it was the biggest challenge."
In addition, the study found that nanotubes with different structures also behave very differently during their growth, with some nanotube structures growing faster and others growing longer under certain conditions.
"Previously it was very difficult to control the chirality, or atomic structure, of nanotubes, particularly when using metal nanoparticles," Bilu Liu said. "The structures may look quite similar, but the properties are very different. In this paper we decode the atomic structure of nanotubes and show how to control precisely that atomic structure."
Additional authors of the study are Jialu Zhang of USC and Xiaomin Tu and Ming Zheng of the National Institute of Standards and Technology,.
The research was funded by the Office of Naval Research and the Defense Threat Reduction Agency of the U.S. Department of Defense.
Suzanne Wu | EurekAlert!
Superconductivity research reveals potential new state of matter
17.08.2017 | DOE/Los Alamos National Laboratory
Spray-on electric rainbows: Making safer electrochromic inks
17.08.2017 | Georgia Institute of Technology
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy