Nanotechnology Today – Fuel Cells, Buckyballs and Carbon Nanotubes


Nanotubes images 

To celebrate the 25th anniversary of National Chemistry Week, we visited the Maryland Nanocenter at the University of Maryland (UMD) to check out the latest research in nanotechnology — this year’s theme for NCW.

Three UMD researchers explain how their work in the nano-scale could lead to better fuel cells, solar cells, cancer treatments and super strong materials made from carbon nanotubes. Check out the video for a first hand look at the exciting applications of nanotechnology available today, and those that are just around the corner.

Drs. Eichhorn and Reutt-Robey at the University of Maryland ‘illuminate’ for us some of the current nano-technology being developed for commercial applications.


Video by Kirk Zamieroski Produced by the American Chemical Society

 

 

Another nanotechnology milestone by NASA engineers (w/video)


QDOTS imagesCAKXSY1K 8(Nanowerk News) A NASA engineer has achieved yet  another milestone in his quest to advance an emerging super-black nanotechnology  that promises to make spacecraft instruments more sensitive without enlarging  their size.

 

A team led by John Hagopian, an optics engineer at NASA’s  Goddard Space Flight Center in Greenbelt, Md., has demonstrated that it can grow  a uniform layer of carbon nanotubes through the use of another emerging  technology called atomic layer deposition or ALD. The marriage of the two  technologies now means that NASA can grow nanotubes on three-dimensional  components, such as complex baffles and tubes commonly used in optical  instruments.           Optics engineer John Hagopian works with a nanotube material sample Optics engineer John Hagopian works with a nanotube material sample.  

“The significance of this is that we have new tools that can  make NASA instruments more sensitive without making our telescopes bigger and  bigger,” Hagopian said. “This demonstrates the power of nanoscale technology,  which is particularly applicable to a new class of less-expensive tiny  satellites called Cubesats that NASA is developing to reduce the cost of space  missions.”

Since beginning his research and development effort five years  ago, Hagopian and his team have made significant strides applying the  carbon-nanotube technology to a number of spaceflight applications, including,  among other things, the suppression of stray light that can overwhelm faint  signals that sensitive detectors are supposed to retrieve.

Super Absorbency

During the research, Hagopian tuned the nano-based super-black  material, making it ideal for this application, absorbing on average more than  99 percent of the ultraviolet, visible, infrared and far-infrared light that  strikes it — a never-before-achieved milestone that now promises to open new  frontiers in scientific discovery. The material consists of a thin coating of  multi-walled carbon nanotubes about 10,000 times thinner than a strand of human  hair.

Once a laboratory novelty grown only on silicon, the NASA team  now grows these forests of vertical carbon tubes on commonly used spacecraft  materials, such as titanium, copper and stainless steel. Tiny gaps between the  tubes collect and trap light, while the carbon absorbs the photons, preventing  them from reflecting off surfaces. Because only a small fraction of light  reflects off the coating, the human eye and sensitive detectors see the material  as black.

Before growing this forest of nanotubes on instrument parts,  however, materials scientists must first deposit a highly uniform foundation or  catalyst layer of iron oxide that supports the nanotube growth. For ALD,  technicians do this by placing a component or some other substrate material  inside a reactor chamber and sequentially pulsing different types of gases to  create an ultra-thin film whose layers are literally no thicker than a single  atom. Once applied, scientists then are ready to actually grow the carbon  nanotubes. They place the component in another oven and heat the part to about  1,832  F (750 C). While it heats, the component is bathed in carbon-containing  feedstock gas.

“The samples we’ve grown to date are flat in shape,” Hagopian  explained. “But given the complex shapes of some instrument components, we  wanted to find a way to grow carbon nanotubes on three-dimensional parts, like  tubes and baffles. The tough part is laying down a uniform catalyst layer.  That’s why we looked to atomic layer deposition instead of other techniques,  which only can apply coverage in the same way you would spray something with  paint from a fixed angle.”
ALD to the Rescue
ALD, first described in the 1980s and later adopted by the  semiconductor industry, is one of many techniques for applying thin films.  However, ALD offers an advantage over competing techniques. Technicians can  accurately control the thickness and composition of the deposited films, even  deep inside pores and cavities. This gives ALD the unique ability to coat in and  around 3-D objects.
NASA Goddard co-investigator Vivek Dwivedi, through a  partnership with the University of Maryland at College Park, is now advancing  ALD reactor technology customized for spaceflight applications.
Lachlan Hyde works with an atomic layer deposition system
Lachlan Hyde, an expert in atomic layer deposition at Australia’s  Melbourne Centre for Nanofabrication, works with one of the organization’s two  ALD systems. (Image: MCN)
To determine the viability of using ALD to create the catalyst  layer, while Dwivedi was building his new ALD reactor, Hagopian engaged through  the Science Exchange the services of the Melbourne Centre for Nanofabrication  (MCN), Australia’s largest nanofabrication research center. The Science Exchange  is an online community marketplace where scientific service providers can offer  their services. The NASA team delivered a number of components, including an  intricately shaped occulter used in a new NASA-developed instrument for  observing planets around other stars.
Through this collaboration, the Australian team fine-tuned the  recipe for laying down the catalyst layer — in other words, the precise  instructions detailing the type of precursor gas, the reactor temperature and  pressure needed to deposit a uniform foundation. “The iron films that we  deposited initially were not as uniform as other coatings we have worked with,  so we needed a methodical development process to achieve the outcomes that NASA  needed for the next step,” said Lachlan Hyde, MCN’s expert in ALD.
The Australian team succeeded, Hagopian said. “We have  successfully grown carbon nanotubes on the samples we provided to MCN and they  demonstrate properties very similar to those we’ve grown using other techniques  for applying the catalyst layer. This has really opened up the possibilities for  us. Our goal of ultimately applying a carbon-nanotube coating to complex  instrument parts is nearly realized.”
Source: NASA

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Vaporware: Scientists Use Cloud of Atoms as Optical Memory Device


QDOTS imagesCAKXSY1K 8Talk about storing data in the cloud. Scientists at the Joint Quantum Institute (JQI) of the National Institute of Standards and Technology (NIST) and the University of Maryland have taken this to a whole new level by demonstrating* that they can store visual images within quite an ethereal memory device—a thin vapor of rubidium atoms. The effort may prove helpful in creating memory for quantum computers.

This brief animation (click link to launch mp4) by the NIST/JQI team shows the NIST logo they stored within a vapor of rubidium atoms and three different portions of it that they were able to extract at will. Animation combines three actual images from the vapor extracted at different times.

Their work builds on an approach developed at the Australian National University, where scientists showed that a rubidium vapor could be manipulated in interesting ways using magnetic fields and lasers. The vapor is contained in a small tube and magnetized, and a laser pulse made up of multiple light frequencies is fired through the tube. The energy level of each rubidium atom changes depending on which frequency strikes it, and these changes within the vapor become a sort of fingerprint of the pulse’s characteristics. If the field’s orientation is flipped, a second pulse fired through the vapor takes on the exact characteristics of the first pulse—in essence, a readout of the fingerprint.

“With our paper, we’ve taken this same idea and applied it to storing an image—basically moving up from storing a single ‘pixel’ of light information to about a hundred,” says Paul Lett, a physicist with JQI and NIST’s Quantum Measurement Division. “By modifying their technique, we have been able to store a simple image in the vapor and extract pieces of it at different times.”

It’s a dramatic increase in the amount of information that can be stored and manipulated with this approach. But because atoms in a vapor are always in motion, the image can only be stored for about 10 milliseconds, and in any case the modifications the team made to the original technique introduce too much noise into the laser signal to make the improvements practically useful. So, should the term vaporware be applied here after all? Not quite, says Lett—because the whole point of the effort was not to build a device for market, but to learn more about how to create memory for next-generation quantum computers.

“What we’ve done here is store an image using classical physics. However, the ultimate goal is to store quantum information, which a quantum computer will need,” he says. “Measuring what the rubidium atoms do as we manipulate them is teaching us how we might use them as quantum bits and what problems those bits might present. This way, when someone builds a solid-state system for a finished computer, we’ll know how to handle them more effectively.”

*J.B. Clark, Q. Glorieux and P.D. Lett. Spatially addressable readout and erasure of an image in a gradient echo memory. New Journal of Physics, doi: 10.1088/1367-2630/15/3/035005, 06 March 2013.