Tag Archives: Georgia Tech

Mini Lisa made possible by ThermoChemical NanoLithography

One of the world’s most recognizable images has undergone a makeover of sorts. According to an Aug. 6, 2013 news item on Azonano, researchers Georgia institute of Technology (Georgia Tech) in the US, have created a mini Mona Lisa,

The world’s most famous painting has now been created on the world’s smallest canvas. Researchers at the Georgia Institute of Technology have “painted” the Mona Lisa on a substrate surface approximately 30 microns in width – or one-third the width of a human hair.

The team’s creation, the “Mini Lisa,” demonstrates a technique that could potentially be used to achieve nanomanufacturing of devices because the team was able to vary the surface concentration of molecules on such short-length scales.

The Aug. 5, 2013 Georgia Tech news release, which originated the news item, provides more technical details,

The image was created with an atomic force microscope and a process called ThermoChemical NanoLithography (TCNL). Going pixel by pixel, the Georgia Tech team positioned a heated cantilever at the substrate surface to create a series of confined nanoscale chemical reactions. By varying only the heat at each location, Ph.D. Candidate Keith Carroll controlled the number of new molecules that were created. The greater the heat, the greater the local concentration. More heat produced the lighter shades of gray, as seen on the Mini Lisa’s forehead and hands. Less heat produced the darker shades in her dress and hair seen when the molecular canvas is visualized using fluorescent dye. Each pixel is spaced by 125 nanometers.

“By tuning the temperature, our team manipulated chemical reactions to yield variations in the molecular concentrations on the nanoscale,” said Jennifer Curtis, an associate professor in the School of Physics and the study’s lead author. “The spatial confinement of these reactions provides the precision required to generate complex chemical images like the Mini Lisa.”

Production of chemical concentration gradients and variations on the sub-micrometer scale are difficult to achieve with other techniques, despite a wide range of applications the process could allow. The Georgia Tech TCNL research collaboration, which includes associate professor Elisa Riedo and Regents Professor Seth Marder, produced chemical gradients of amine groups, but expects that the process could be extended for use with other materials.

“We envision TCNL will be capable of patterning gradients of other physical or chemical properties, such as conductivity of graphene,” Curtis said. “This technique should enable a wide range of previously inaccessible experiments and applications in fields as diverse as nanoelectronics, optoelectronics and bioengineering.”

Another advantage, according to Curtis, is that atomic force microscopes are fairly common and the thermal control is relatively straightforward, making the approach accessible to both academic and industrial laboratories.  To facilitate their vision of nano-manufacturing devices with TCNL, the Georgia Tech team has recently integrated nanoarrays of five thermal cantilevers to accelerate the pace of production. Because the technique provides high spatial resolutions at a speed faster than other existing methods, even with a single cantilever, Curtis is hopeful that TCNL will provide the option of nanoscale printing integrated with the fabrication of large quantities of surfaces or everyday materials whose dimensions are more than one billion times larger than the TCNL features themselves.

Here’s an image of the AFM and the cantilever used in the TCNL process to create the ‘Mini Lisa’,

Atomic force microscope (AFM) modified with a thermal cantilever. The AFM scanner allows for precise positioning on the nanoscale while the thermal cantilever induces local nanoscale chemical reactions. Courtesy Georgia Tech

Atomic force microscope (AFM) modified with a thermal cantilever. The AFM scanner allows for precise positioning on the nanoscale while the thermal cantilever induces local nanoscale chemical reactions. Courtesy Georgia Tech

Finally, the “Mini Lisa’,

Georgia Tech researchers have created the "Mini Lisa" on a substrate surface approximately 30 microns in width. The image demonstrates a technique that could potentially be used to achieve nano-manufacturing of devices because the team was able to vary the surface concentration of molecules on such short length scales. Courtesy Georgia Tech

Georgia Tech researchers have created the “Mini Lisa” on a substrate surface approximately 30 microns in width. The image demonstrates a technique that could potentially be used to achieve nano-manufacturing of devices because the team was able to vary the surface concentration of molecules on such short length scales. Courtesy Georgia Tech

For those who can’t get enough of the ‘Mini Lisa’ or TCNL, here’s a link to and a citation for the research team’s published paper,

Fabricating Nanoscale Chemical Gradients with ThermoChemical NanoLithography by Keith M. Carroll, Anthony J. Giordano, Debin Wang, Vamsi K. Kodali, Jan Scrimgeour, William P. King, Seth R. Marder, Elisa Riedo, and Jennifer E. Curtis. Langmuir, 2013, 29 (27), pp 8675–8682 DOI: 10.1021/la400996w Publication Date (Web): June 10, 2013
Copyright © 2013 American Chemical Society

This article is behind a paywall.

Solar cells made even more leaflike with inclusion of nanocellulose fibers

Researchers at the US Georgia  Institute of Technology (Georgia Tech)  and Purdue University (Indiana) have used cellulose nanocrystals (CNC), which is also known as nanocrystalline cellulose (NCC), to create solar cells that have greater efficiency and can be recycled. From the Mar. 26, 2013 news item on Nanowerk,

Georgia Institute of Technology and Purdue University researchers have developed efficient solar cells using natural substrates derived from plants such as trees. Just as importantly, by fabricating them on cellulose nanocrystal (CNC) substrates, the solar cells can be quickly recycled in water at the end of their lifecycle.

The Georgia Tech Mar. 25, 2013 news release, which originated the news item,

The researchers report that the organic solar cells reach a power conversion efficiency of 2.7 percent, an unprecedented figure for cells on substrates derived from renewable raw materials. The CNC substrates on which the solar cells are fabricated are optically transparent, enabling light to pass through them before being absorbed by a very thin layer of an organic semiconductor. During the recycling process, the solar cells are simply immersed in water at room temperature. Within only minutes, the CNC substrate dissolves and the solar cell can be separated easily into its major components.

Georgia Tech College of Engineering Professor Bernard Kippelen led the study and says his team’s project opens the door for a truly recyclable, sustainable and renewable solar cell technology.

“The development and performance of organic substrates in solar technology continues to improve, providing engineers with a good indication of future applications,” said Kippelen, who is also the director of Georgia Tech’s Center for Organic Photonics and Electronics (COPE). “But organic solar cells must be recyclable. Otherwise we are simply solving one problem, less dependence on fossil fuels, while creating another, a technology that produces energy from renewable sources but is not disposable at the end of its lifecycle.”

To date, organic solar cells have been typically fabricated on glass or plastic. Neither is easily recyclable, and petroleum-based substrates are not very eco-friendly. For instance, if cells fabricated on glass were to break during manufacturing or installation, the useless materials would be difficult to dispose of. Paper substrates are better for the environment, but have shown limited performance because of high surface roughness or porosity. However, cellulose nanomaterials made from wood are green, renewable and sustainable. The substrates have a low surface roughness of only about two nanometers.

“Our next steps will be to work toward improving the power conversion efficiency over 10 percent, levels similar to solar cells fabricated on glass or petroleum-based substrates,” said Kippelen. The group plans to achieve this by optimizing the optical properties of the solar cell’s electrode.

The news release also notes the impact that using cellulose nanomaterials could have economically,

There’s also another positive impact of using natural products to create cellulose nanomaterials. The nation’s forest product industry projects that tens of millions of tons of them could be produced once large-scale production begins, potentially in the next five years.

One might almost  suspect that the forest products industry is experiencing financial difficulty.

The researchers’ paper was published by Scientific Reports, an open access journal from the Nature Publishing Group,

Recyclable organic solar cells on cellulose nanocrystal substrates by Yinhua Zhou, Canek Fuentes-Hernandez, Talha M. Khan, Jen-Chieh Liu, James Hsu, Jae Won Shim, Amir Dindar, Jeffrey P. Youngblood, Robert J. Moon, & Bernard Kippelen. Scientific Reports  3, Article number: 1536  doi:10.1038/srep01536 Published 25 March 2013

In closing, the news release notes that a provisional patent has been filed at the US Patent Office.And one final note, I have previously commented on how confusing the reported power conversion rates are. You’ll find a recent comment in my Mar. 8, 2013 posting about Ted Sargent’s work with colloidal quantum dots and solar cells.

Samsung ‘GROs’ graphene-based micro-antennas and a brief bit about the business of nanotechnology

A Feb. 22, 2013 news item on Nanowerk highlights a Samsung university grant (GRO) programme which announced funding for graphene-based micro-antennas,

The Graphene-Enabled Wireless Communication project, one of the award-winning proposals under the Samsung Global Research Outreach (GRO) programme, aims to use graphene antennas to implement wireless communication over very short distances (no more than a centimetre) with high-capacity information transmission (tens or hundreds of gigabits per second). Antennas made ??of [sic] graphene could radiate electromagnetic waves in the terahertz band and would allow for high-speed information transmission. Thanks to the unique properties of this nanomaterial, the new graphene-based antenna technology would also make it possible to manufacture antennas a thousand times smaller than those currently used.

The GRO programme—an annual call for research proposals by the Samsung Advanced Institute of Technology (Seoul, South Korea)—has provided the UPC-led project with US$120,000 in financial support.

The Graphene-Enabled Wireless Communication project is a joint project (from the news item; Note: A link has been removed),

“Graphene-Enabled Wireless Communications” – a proposal submitted by an interdepartmental team based at the Universitat Politècnica de Catalunya, BarcelonaTech (UPC) and the Georgia Institute of Technology (Georgia Tech)—will receive US$120,000 to develop micrometre-scale graphene antennas capable of transmitting information at a high speed over very short distances. The project will be carried out in the coming months.

The Graphene-Enabled Wireless Communication project, one of the award-winning proposals under the Samsung Global Research Outreach (GRO) programme, aims to use graphene antennas to implement wireless communication over very short distances (no more than a centimetre) with high-capacity information transmission (tens or hundreds of gigabits per second). Antennas made ??of graphene could radiate electromagnetic waves in the terahertz band and would allow for high-speed information transmission. Thanks to the unique properties of this nanomaterial, the new graphene-based antenna technology would also make it possible to manufacture antennas a thousand times smaller than those currently used.

There’s more about the Graphene-Enabled Wireless Communication project here,

 A remarkably promising application of graphene is that of Graphene-enabled Wireless Communications (GWC). GWC advocate for the use of graphene-based plasmonic antennas -graphennas, see Fig. 1- whose plasmonic effects allow them to radiate EM waves in the terahertz band (0.1 – 10 THz). Moreover, preliminary results sustain that this frequency band is up to two orders of magnitude below the optical frequencies at which metallic antennas of the same size resonate, thereby enhancing the transmission range of graphene-based antennas and lowering the requirements on the corresponding transceivers. In short, graphene enables the implementation of nano-antennas just a few micrometers in size that are not doable with traditional metallic materials.

Thanks to both the reduced size and unique radiation capabilities of ZZ, GWC may represent a breakthrough in the ultra-short range communications research area. In this project we will study the application of GWC within the scenario of off-chip communication, which includes communication between different chips of a given device, e.g. a cell phone.

A new term, graphenna, appears to be have been coined. The news item goes on to offer more detail about the project and about the number of collaborating institutions,

The first stage of the project, launched in October 2012, focuses on the theoretical foundations of wireless communications over short distances using graphene antennas. In particular, the group is analysing the behaviour of electromagnetic waves in the terahertz band for very short distances, and investigating how coding and modulation schemes can be adapted to achieve high transmission rates while maintaining low power consumption.

The group believes the main benefits of the project in the medium term will derive from its application for internal communication in multicore processors. Processors of this type have a number of sub-processors that share and execute tasks in parallel. The application of wireless communication in this area will make it possible to integrate thousands of sub-processors within a single processor, which is not feasible with current communication systems.

The results of the project will lead to an increase in the computational performance of these devices. This improvement would allow large amounts of data to be processed at very high speed, which would be very useful for streamlining data management at processing centres (“big data”) used, for example, in systems like Facebook and Google. The project, which builds on previous results obtained with the collaboration of the University of Wuppertal in Germany, the Royal Institute of Technology (KTH) in Sweden, and Georgia Tech in the United States, is expected to yield its first results in April 2013.

The project is being carried out by the NaNoNetworking Centre in Catalonia (N3Cat), a network formed at the initiative of researchers with the UPC’s departments of Electronic Engineering and Computer Architecture, together with colleagues at Georgia Tech.

Anyone interested in  Samsung’s GRO programme can find more here,

The SAMSUNG Global Research Outreach (GRO) program, open to leading universities around the world, is Samsung Electronics, Co., Ltd. & related Samsung companies (SAMSUNG)’s annual call for research proposals.

As this Samsung-funded research project is being announced, Dexter Johnson details the business failure of NanoInk in a Feb. 22, 2013 posting on his Nanoclast blog (on the IEEE [International Institute of Electrical and Electronics Engineers] website), Note: Links have been removed,

One of the United State’s first nanotechnology companies, NanoInk, has gone belly up, joining a host of high-profile nanotechnology-based companies that have shuttered their doors in the last 12 months: Konarka, A123 Systems and Ener1.

These other three companies were all tied to the energy markets (solar in the case of Konarka and batteries for both A123 and Ener1), which are typically volatile, with a fair number of shuttered businesses dotting their landscapes. But NanoInk is a venerable old company in comparison to these other three and is more in what could be characterized as the “picks-and-shovels” side of the nanotechnology business, microscopy tools.

Dexter goes on to provide an  analysis of the NanoInk situation which makes for some very interesting reading along with the comments—some feisty, some not—his posting has provoked.

I am juxtaposing the Samsung funding announcement with this mention of Dexter’s piece regarding a  ‘nanotechnology’ business failure in an effort to provide some balance between enthusiasm for the research and the realities of developing businesses and products based on that research.

Developing self-powered batteries for pacemakers

Imagine having your chest cracked open every time your pacemaker needs to have its battery changed? It’s not a pleasant thought and researchers are working on a number of approaches to change that situation.  Scientists from the University of Michigan have presented the results from some preliminary testing of a device that harvests energy from heartbeats (from the Nov. 4, 2012 news release on EurekAlert),

In a preliminary study, researchers tested an energy-harvesting device that uses piezoelectricity — electrical charge generated from motion. The approach is a promising technological solution for pacemakers, because they require only small amounts of power to operate, said M. Amin Karami, Ph.D., lead author of the study and research fellow in the Department of Aerospace Engineering at the University of Michigan in Ann Arbor.

Piezoelectricity might also power other implantable cardiac devices like defibrillators, which also have minimal energy needs, he said.

Today’s pacemakers must be replaced every five to seven years when their batteries run out, which is costly and inconvenient, Karami said.

A University of Michigan at Ann Arbor March 2, 2012 news release provides more technical detail about this energy-harvesting battery which the researchers had not then tested,

… A hundredth-of-an-inch thin slice of a special “piezoelectric” ceramic material would essentially catch heartbeat vibrations and briefly expand in response. Piezoelectric materials’ claim to fame is that they can convert mechanical stress (which causes them to expand) into an electric voltage.

Karami and his colleague Daniel Inman, chair of Aerospace Engineering at U-M, have precisely engineered the ceramic layer to a shape that can harvest vibrations across a broad range of frequencies. They also incorporated magnets, whose additional force field can drastically boost the electric signal that results from the vibrations.

The new device could generate 10 microwatts of power, which is about eight times the amount a pacemaker needs to operate, Karami said. It always generates more energy than the pacemaker requires, and it performs at heart rates from 7 to 700 beats per minute. That’s well below and above the normal range.

Karami and Inman originally designed the harvester for light unmanned airplanes, where it could generate power from wing vibrations.

Since March 2012, the researchers have tested the prototype (from the Nov. 4, 2012 news release on EurekAlert),

Researchers measured heartbeat-induced vibrations in the chest. Then, they used a “shaker” to reproduce the vibrations in the laboratory and connected it to a prototype cardiac energy harvester they developed. Measurements of the prototype’s performance, based on sets of 100 simulated heartbeats at various heart rates, showed the energy harvester performed as the scientists had predicted — generating more than 10 times the power than modern pacemakers require. The next step will be implanting the energy harvester, which is about half the size of batteries now used in pacemakers, Karami said. Researchers hope to integrate their technology into commercial pacemakers.

There are other teams working on energy-harvesting batteries, in my July 12, 2010 posting I mentioned a team led by Professor Zhong Lin Wang at Georgia Tech (Georgia Institute of Technology in the US) which is working on batteries that harvest energy from biomechanical motion such as heart beats, finger tapping, breathing, etc.

Nanotechnology’s economic impacts and full lifecycle assessments

A paper presented at the International Symposium on Assessing the Economic Impact of Nanotechnology, held March 27 – 28, 2012 in Washington, D.C advises that assessments of the economic impacts of nanotechnology need to be more inclusive. From the March 28, 2012 news item on Nanowerk,

“Nanotechnology promises to foster green and sustainable growth in many product and process areas,” said Shapira [Philip Shapira], a professor with Georgia Tech’s [US]  School of Public Policy and the Manchester Institute of Innovation Research at the Manchester Business School in the United Kingdom. “Although nanotechnology commercialization is still in its early phases, we need now to get a better sense of what markets will grow and how new nanotechnology products will impact sustainability. This includes balancing gains in efficiency and performance against the net energy, environmental, carbon and other costs associated with the production, use and end-of-life disposal or recycling of nanotechnology products.”

But because nanotechnology underlies many different industries, assessing and forecasting its impact won’t be easy. “Compared to information technology and biotechnology, for example, nanotechnology has more of the characteristics of a general technology such as the development of electric power,” said Youtie [Jan Youtie], director of policy research services at Georgia Tech’s Enterprise Innovation Institute. “That makes it difficult to analyze the value of products and processes that are enabled by the technology. We hope that our paper will provide background information and help frame the discussion about making those assessments.”

From the March 27, 2012 Georgia Institute of Technology news release,

For their paper, co-authors Shapira and Youtie examined a subset of green nanotechnologies that aim to enable sustainable energy, improve environmental quality, and provide healthy drinking water for areas of the world that now lack it. They argue that the lifecycle of nanotechnology products must be included in the assessment.

I was hoping for a bit more detail about how one would go about including nanotechnology-enabled products in this type of economic impact assessment but this is all I could find (from the news release),

In their paper, Youtie and Shapira cite several examples of green nanotechnology, discuss the potential impacts of the technology, and review forecasts that have been made. Examples of green nanotechnology they cite include:

  • Nano-enabled solar cells that use lower-cost organic materials, as opposed to current photovoltaic technologies that require rare materials such as platinum;
  • Nanogenerators that use piezoelectric materials such as zinc oxide nanowires to convert human movement into energy;
  • Energy storage applications in which nanotechnology materials improve existing batteries and nano-enabled fuel cells;
  • Thermal energy applications, such as nano-enabled insulation;
  • Fuel catalysis in which nanoparticles improve the production and refining of fuels and reduce emissions from automobiles;
  • Technologies used to provide safe drinking water through improved water treatment, desalination and reuse.

I checked both Philip Shapira‘s webpage and Jan Youtie‘s at Georgia Tech to find that neither lists this latest work, which hopefully includes additional detail. I’m hopeful there’ll be a document published in the proceedings for this symposium and access will be possible.

On another note, I did mention this symposium in my Jan. 27, 2012 posting where I speculated about the Canadian participation. I did get a response (March 5, 2012)  from Vanessa Clive, Nanotechnology File, Industry Sector, Industry Canada who kindly cleared up my confusion,

A colleague forwarded the extract from your blog below. Thank you for your interest in the OECD Working Party on Nanotechnology (WPN) work, and giving some additional public profile to its work is welcome. However, some correction is needed, please, to keep the record straight.

“It’s a lot to infer from a list of speakers but I’m going to do it anyway. Given that the only Canadian listed as an invited speaker for a prestigious (OECD/AAAS/NNI as hosts) symposium about nanotechnology’s economic impacts, is someone strongly associated with NCC, it would seem to confirm that Canadians do have an important R&D (research and development) lead in an area of international interest.

One thing about this symposium does surprise and that’s the absence of Vanessa Clive from Industry Canada. She co-authored the OECD’s 2010 report, The Impacts of Nanotechnology on Companies: Policy Insights from Case Studies and would seem a natural choice as one of the speakers on the economic impacts that nanotechnology might have in the future.”

I am a member of the organizing committee, on the OECD WPN side, for the Washington Symposium in March which will focus on the need and, in turn, options for development of metrics for evaluation of the economic impacts of nano. As committee member, I was actively involved in identifying potential Canadian speakers for agenda slots. Apart from the co-sponsors whose generosity made the event possible, countries were limited to one or two speakers in order to bring in experts from as many interested countries as possible. The second Canadian expert which we had invited to participate had to pull out, unfortunately.

Also, the OECD project on nano impacts on business was co-designed and co-led by me, another colleague here at the time, and our Swiss colleague, but the report itself was written by OECD staff.

I did send (March 5, 2012)  a followup email with more questions but I gather time was tight as I’ve not heard back.

In any event, I’m looking forward to hearing more about this symposium, however that occurs, in the coming weeks and months.

Finger pinches today, heartbeats tomorrow and electricity forever

Devices powered by energy generated and harvested from one’s own body have been of tremendous interest to me. Last year I mentioned some research in this area by Professor Zhong Lin Wang at Georgia Tech (Georgia Institute of Technology) in a July 12, 2010 posting. Well, Wang and his team recently announced that they have developed the first commercially viable nanogenerator. From the March 29, 2011 news item on Physorg.com,

After six years of intensive effort, scientists are reporting development of the first commercially viable nanogenerator, a flexible chip that can use body movements — a finger pinch now en route to a pulse beat in the future — to generate electricity. Speaking here today at the 241st National Meeting & Exposition of the American Chemical Society, they described boosting the device’s power output by thousands times and its voltage by 150 times to finally move it out of the lab and toward everyday life.

“This development represents a milestone toward producing portable electronics that can be powered by body movements without the use of batteries or electrical outlets,” said lead scientist Zhong Lin Wang, Ph.D. “Our nanogenerators are poised to change lives in the future. Their potential is only limited by one’s imagination.”

Here’s how it works  (from Kit Eaton’s article on Fast Company),

The trick used by Dr. Zhong Lin Wang’s team has been to utilize nanowires made of zinc oxide (ZnO). ZnO is a piezoelectric material–meaning it changes shape slightly when an electrical field is applied across it, or a current is generated when it’s flexed by an external force. By combining nanoscopic wires (each 500 times narrower than a human hair) of ZnO into a flexible bundle, the team found it could generate truly workable amounts of energy. The bundle is actually bonded to a flexible polymer slice, and in the experimental setup five pinky-nail-size nanogenerators were stacked up to create a power supply that can push out 1 micro Amp at about 3 volts. That doesn’t sound like a lot, but it was enough to power an LED and an LCD screen in a demonstration of the technology’s effectiveness.

Dexter Johnson at Nanoclast on the IEEE (Institute of Electrical Engineering and Electronics) website notes in his March 30, 2010 posting (http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/powering-our-electronic-devices-with-nanogenerators-looks-more-feasible) that the nanogenerator’s commercial viability is dependent on work being done at the University of Illinois,

I would have happily chalked this story [about the nanogenerator] up to one more excellent job of getting nanomaterial research into the mainstream press, but because of recent work by Eric Pop and his colleagues at the University of Illinois’s Beckman Institute in reducing the energy consumed by electronic devices it seems a bit more intriguing now.

So low is the energy consumption of the electronics proposed by the University of Illinois research it is to the point where a mobile device may not need a battery but could possibly operate on the energy generated from piezoelectric-enabled nanogenerators contained within such devices like those proposed by Wang.

I have a suspicion it’s going to be a while before I will be wearing nanogenerators to harvest the electricity my body produces. Meanwhile, I have some questions about the possible uses for nanogenerators (from the Kit Eaton article),

The search for tiny power generator technology has slowly inched forward for years for good reason–there are a trillion medical and surveillance uses–not to mention countless consumer electronics applications– for a system that could grab electrical power from something nearby that’s moving even just a tiny bit. Imagine an implanted insulin pump, or a pacemaker that’s powered by the throbbing of the heart or blood vessels nearby (and then imagine the pacemaker powering the heart, which is powered by the pacemaker, and so on and so on….) and you see how useful such a system could be.

It’s the reference to surveillance that makes me a little uneasy.