285-micron racecar (credit: Vienna University of Technology)

For those interested in atomically precise manufacturing, 3D-printing is an interesting microscale technology for making centimeter-scale objects. We commented on this technology a few months ago with the introduction of two competing technologies for printing complex digitally-designed plastic consumer items. Foresight Senior Associate Charles Vollum sends word of the extension of 3D-printing to nanoscale (approximately 100 nm) resolution. In addition, the new procedure is much faster and enables true 3D fabrication, without requiring layer-by-layer fabrication. A hat tip to KurzweilAI for describing this Vienna University of Technology news release “3D-printer with nano-precision“:

Printing three dimensional objects with incredibly fine details is now possible using “two-photon lithography”. With this technology, tiny structures on a nanometer scale can be fabricated. Researchers at the Vienna University of Technology (TU Vienna) have now made a major breakthrough in speeding up this printing technique: The high-precision-3D-printer at TU Vienna is orders of magnitude faster than similar devices (see video). This opens up completely new areas of application, such as in medicine.

The video shows the 3d-printing process in real time. Due to the very fast guiding of the laser beam, 100 layers, consisting of approximately 200 single lines each, are produced in four minutes.

Setting a New World Record

The 3D printer uses a liquid resin, which is hardened at precisely the correct spots by a focused laser beam. The focal point of the laser beam is guided through the resin by movable mirrors and leaves behind a polymerized line of solid polymer, just a few hundred nanometers wide. This high resolution enables the creation of intricately structured sculptures as tiny as a grain of sand. “Until now, this technique used to be quite slow”, says Professor Jürgen Stampfl from the Institute of Materials Science and Technology at the TU Vienna. “The printing speed used to be measured in millimeters per second – our device can do five meters in one second.” In two-photon lithography, this is a world record. …

Photoactive Molecules Harden the Resin

3D-printing is not all about mechanics – chemists had a crucial role to play in this project too. “The resin contains molecules, which are activated by the laser light. They induce a chain reaction in other components of the resin, so-called monomers, and turn them into a solid”, says Jan Torgersen. These initiator molecules are only activated if they absorb two photons of the laser beam at once – and this only happens in the very center of the laser beam, where the intensity is highest. In contrast to conventional 3D-printing techniques, solid material can be created anywhere within the liquid resin rather than on top of the previously created layer only. Therefore, the working surface does not have to be specially prepared before the next layer can be produced (see Video), which saves a lot of time. A team of chemists led by Professor Robert Liska (TU Vienna) developed the suitable initiators for this special resin. …

Because of the dramatically increased speed, much larger objects can now be created in a given period of time. This makes two-photon-lithography an interesting technique for industry. At the TU Vienna, scientists are now developing bio-compatible resins for medical applications. They can be used to create scaffolds to which living cells can attach themselves facilitating the systematic creation of biological tissues. The 3d printer could also be used to create tailor made construction parts for biomedical technology or nanotechnology.

We are still three orders of magnitude away from atomic precision and limited in the choice of materials to one polymer; however, the more useful 3D printing technology becomes, the more interest to extend it toward general purpose atomically precise manufacturing.
—James Lewis, PhD

Miguel F. Aznar, Foresight’s Director of Education, sends the following nanotechnology education items.

Nano Outreach and Education in Ibero America

NanoDYF promotes nanoscience / nanotechnology outreach and education in Ibero America. The NanoDYF 2012 conference in Puebla, Mexico 2012 June 11 – 13, will draw together leaders in research, education, business, and politics to share discoveries and discuss objectives for this outreach. I will present on critical thinking about nanotechnology. More information is at http://www.nanodyf.org/ (use translate.Google.com if you don’t read Spanish). The NanoMex 2012 Conference runs immediately afterward, June 13 – 15, at the same location.

Buckyball Toy

Would you like a Buckyball model to hang from your ceiling? Trying to teach someone how hexagons and pentagons drive the shape of C₆₀? Would you like to see which size Buckyballs can form? Having trouble visualizing armchair and zig-zag carbon nanotubes? Would you like to let your mind wander while toying with shapes that carbon can form? About $3 lets you model a C₆₀. Buy 2 x $3 to model C₇₀, C₇₆, C₈₂, etc. Buy more to model carbon nanotubes.

These are not general purpose models. Each “carbon” is black plastic with 3 equally distributed bonding bumps in a plane and “bonds” are white plastic tubes that fit snugly over the bumps. One of the three bonds is an implied double bond, so if identifying it is important, a permanent marker is easiest. Spray-painting 1/3 of the tubes might look better. Diamond cannot be modeled with this kit, as it requires all four bonds exposed for tetrahedral bonding. Also, this kit is much smaller than the near-standard Prentice-Hall molecular modeling kits. It will not connect to those.

The model is easy to assemble, but holds together for hanging, handing around, or rolling on the floor. The least expensive I’ve found is at Suntekstore.com, which ships free out of Hong Kong. See here. If you would like to sponsor a school by providing a class-set of these kits, I would be happy to facilitate (aznar@foresight.org).

Swiss Children Learn Nano Fundamentals

The Switzerland-based Innovation Society has developed SimplyNano 1 (use translate.Google, if you don’t read German), an experiment kit being distributed to 7th – 10th grade classrooms in Switzerland. It focuses on nano dimensions, surfaces, and reactivity. It includes teaching guides plus materials to make a Lego + laser model of an atomic force microscope. Read a short article translated to English.

I have not received a kit yet, but if as good as it looks and priced reasonably, it could improve nano education in the US. When / if I can answer these questions in the affirmative, I will repost and welcome those who would like to sponsor a school for acquiring a set of these kits.

Miguel F. Aznar
Director of Education
Foresight Institute

A couple months ago we noted that Abundance, by Foresight Advisor Peter Diamandis and science writer Steven Kotler hit #1 on both Amazon and BarnesAndNoble. On Wednesday, April 11, Singularity University will present a live webcast with co-founder and chairman Peter H. Diamandis on Abundance:

Diamandis will present the case that the world is getting better at an accelerating rate through the convergence of four powerful forces: the exponential advancement of technology, DIY (Do It Yourself) innovators, Techno-philanthropists, and the Rising Billion, which, acting together, will create abundance in the areas of clean water, nutritious food, affordable housing, personalized education, top-tier global health care, and ubiquitous energy – helping to solve humanity’s biggest challenges.

Diamandis co-authored Abundance with award-winning technology writer Steven Kotler, bringing together decades of data and extensive interviews with hundreds of innovators and entrepreneurs, including Larry Page, Steven Hawking, Dean Kamen, Daniel Kahneman, Elon Musk, Bill Joy, Stewart Brand, Jeff Skoll, Ray Kurzweil, Ratan Tata, and Craig Venter.

The Wall Street Journal called Abundance “a manifesto for the future that is grounded in practical solutions.” The Economist Magazine said it was “a godsend for those who suffer from Armageddon fatigue!” Sir Richard Branson said: “Abundance provides proof that the proper combination of technology, people and capital can meet any grand challenge.”

Peter Diamandis co-founded Singularity University with Ray Kurzweil in 2008, and currently serves as its Chairman and a member of the Faculty. He is also Founder and Chairman of the X PRIZE Foundation, which leads the world in designing and launching large incentive prizes to drive radical breakthroughs in the areas of exploration, energy and environment, education, global development and life sciences. Diamandis is a leading speaker on innovation, counseling senior business leaders how to utilize exponential technologies and incentivized innovation to dramatically accelerate their business and career objectives. Dr. Diamandis earned a BS in molecular genetics and aerospace engineering from MIT, and an MD from Harvard Medical School. He is also known for “Peter’s Laws,” including “The best way to predict the future is to create it yourself!”

Webcast participation requires registration. Questions can be submitted in advance or during the webcast via Twitter (#whichwaynext).
—James Lewis, PhD

As synthetic biology seeks to build ever more complex biological machines, the possibility of a bridge from biological to artificial molecular machine systems grows less far-fetched. Recent advances in yeast molecular biology are leading to the ability to make more complex molecular machines in yeast, substantially augmenting the synthetic biology toolkit. A hat tip to ScienceDaily for reprinting this AlphaGalileo news release from Imperial College London: “Scientists develop tools to make more complex biological machines from yeast“:

Scientists are one step closer to making more complex microscopic biological machines, following improvements in the way that they can “re-wire” DNA in yeast, according to research published today in the journal PLoS ONE [open access article].

The researchers, from Imperial College London, have demonstrated a way of creating a new type of biological “wire”, using proteins that interact with DNA and behave like wires in electronic circuitry. The scientists say the advantage of their new biological wire is that it can be re-engineered over and over again to create potentially billions of connections between DNA components. Previously, scientists have had a limited number of “wires” available with which to link DNA components in biological machines, restricting the complexity that could be achieved.

The team has also developed more of the fundamental DNA components, called “promoters”, which are needed for re-programming yeast to perform different tasks. Scientists currently have a very limited catalogue of components from which to engineer biological machines. By enlarging the components pool and making it freely available to the scientific community via rapid Open Access publication, the team in today’s study aims to spur on development in the field of synthetic biology.

Future applications of this work could include tiny yeast-based machines that can be dropped into water supplies to detect contaminants, and yeast that records environmental conditions during the manufacture of biofuels to determine if improvements can be made to the production process.

Dr Tom Ellis, senior author of the paper from the Centre for Synthetic Biology and Innovation and the Department of Bioengineering at Imperial College London, says: “From viticulture to making bread, humans have been working with yeast for thousands of years to enhance society. Excitingly, our work is taking us closer to developing more complex biological machines with yeast. These tiny biological machines could help to improve things such as pollution monitoring and cleaner fuels, which could make a difference in all our lives.”

Dr Benjamin Blount, first author of the paper from the Centre for Synthetic Biology and Innovation and the Department of Bioengineering at Imperial College London, says: “Our new approach to re-wiring yeast opens the door to an exciting array of more complex biological devices, including cells engineered to carry out tasks similar to computers.”

In the study, the Imperial researchers modified a protein-based technology called TAL Effectors, which produce TALOR proteins, with similar qualities to wires in electronic devices. These TALORS can be easily re-engineered, which means that they can connect with many DNA-based components without causing a short circuit in the device.

The team says their research now provides biological engineers working in yeast with a valuable new toolbox.

Professor Richard Kitney, Co-Director of the Centre for Synthetic Biology and Innovation at the College, adds: “The work by Dr Ellis and the team at the Centre really takes us closer to developing much more complex biological machines with yeast, which may help to usher in a new age where biological machines could help to improve our health, the way we work, play and live.”

Professor Paul Freemont, Co-Director of the Centre for Synthetic Biology and Innovation at the College, concludes: “One of the core aims of the Centre is to provide tools and resources to the wider scientific community by sharing our research. Dr Ellis’s team has now begun to assemble characterised biological parts for yeast that will be available to researchers both in academia and industry.”

Promoters are DNA sequences that signal transcription of a gene to make a messenger RNA molecule that is then translated to make the protein product encoded by the gene. By systematically mutagenizing the core sequence of one promoter, the researchers created a library of 36 promoters that could be independently regulated. They also created a library of proteins to specifically turn off individual variant promoters. They thus designed a complex network of gene regulation that can be used for arbitrary engineering purposes rather than those networks that have evolved to fit the yeast’s own metabolic needs. One wonderful aspect of this work is that, not only are the results published in an open access journal rather than sequestered behind a pay wall, but the biological “parts” created are available to other biological engineers to elaborate the toolbox that is available to synthetic biology and, perhaps eventually, for a folded polymer path toward productive nanosystems. IMHO, this collaborative “Open Source-like” approach being pursued in synthetic biology provides an admirable paradigm for the development of advanced nanotechnology.
—James Lewis, PhD

Photo and description courtesy of University of Washington

“The various levels of electrical signal from the sequence of a DNA strand pulled through a nanopore reader (top) corresponds to specific DNA nucleotides, thymine, adenine, cytosine and guanine (bottom).”

We recently noted the contribution of nanotechnology-based DNA sequencing methods to research and to the emerging field of personalized medicine. Another major step along this path was taken more recently by combining a mutated protein pore with a DNA polymerase molecular motor. A hat tip to ScienceDaily for reprinting this University of Washington news release written by Vince Stricherz “Tiny reader makes fast, cheap DNA sequencing feasible“:

Researchers have devised a nanoscale sensor to electronically read the sequence of a single DNA molecule, a technique that is fast and inexpensive and could make DNA sequencing widely available.

The technique could lead to affordable personalized medicine, potentially revealing predispositions for afflictions such as cancer, diabetes or addiction.

“There is a clear path to a workable, easily produced sequencing platform,” said Jens Gundlach, a University of Washington physics professor who leads the research team. “We augmented a protein nanopore we developed for this purpose with a molecular motor that moves a DNA strand through the pore a nucleotide at a time.”

The researchers previously reported creating the nanopore by genetically engineering a protein pore from a mycobacterium. The nanopore, from Mycobacterium smegmatis porin A, has an opening 1 billionth of a meter in size, just large enough for a single DNA strand to pass through.

To make it work as a reader, the nanopore was placed in a membrane surrounded by potassium-chloride solution, with a small voltage applied to create an ion current flowing through the nanopore. The electrical signature changes depending on the type of nucleotide traveling through the nanopore. Each type of DNA nucleotide – cytosine, guanine, adenine and thymine – produces a distinctive signature.

The researchers attached a molecular motor, taken from an enzyme associated with replication of a virus, to pull the DNA strand through the nanopore reader. The motor was first used in a similar effort by researchers at the University of California, Santa Cruz, but they used a different pore that could not distinguish the different nucleotide types.

Gundlach is the corresponding author of a paper published online March 25 by Nature Biotechnology [abstract] that reports a successful demonstration of the new technique using six different strands of DNA. The results corresponded to the already known DNA sequence of the strands, which had readable regions 42 to 53 nucleotides long.

“The motor pulls the strand through the pore at a manageable speed of tens of milliseconds per nucleotide, which is slow enough to be able to read the current signal,” Gundlach said.

Gundlach said the nanopore technique also can be used to identify how DNA is modified in a given individual. Such modifications, referred to as epigenetic DNA modifications, take place as chemical reactions within cells and are underlying causes of various conditions.

“Epigenetic modifications are rather important for things like cancer,” he said. Being able to provide DNA sequencing that can identify epigenetic changes “is one of the charms of the nanopore sequencing method.”

The ability to identify epigenetic modifications (mostly methylations of specific nucleotides) is indeed a plus, although we can hope that with further development the technology will be able to read DNA sequences far longer than 42 to 53 nucleotides. Because repeating sequences are prevalent in the human genome, the ability to do long reads is very important.
—James Lewis, PhD

Photo and description courtesy of UMass Amherst

“A card-sized pad of Geckskin can firmly attach very heavy objects such as this 42-inch television weighing about 40 lbs. (18 kg) to a smooth vertical surface. The key innovation by Bartlett and colleagues was to create a soft pad woven into a stiff fabric that includes a synthetic tendon. Together these features allow the stiff yet flexible pad to “drape” over a surface to maximize contact.”

Another example of current nanotechnology too cool to ignore is provided by a card-sized adhesive that can support up to 700 pounds on a glass surface, be easily released, and reused many times. A hat tip to ScienceDaily for reprinting this UMass Amherst news release “Inspired by gecko feet, UMass Amherst scientists invent super-adhesive material“:

For years, biologists have been amazed by the power of gecko feet, which let these 5-ounce lizards produce an adhesive force roughly equivalent to carrying nine pounds up a wall without slipping. Now, a team of polymer scientists and a biologist at the University of Massachusetts Amherst have discovered exactly how the gecko does it, leading them to invent “Geckskin,” a device that can hold 700 pounds on a smooth wall.

Doctoral candidate Michael Bartlett in Alfred Crosby’s polymer science and engineering lab at UMass Amherst is the lead author of their article describing the discovery in the current online issue of Advanced Materials [abstract]. The group includes biologist Duncan Irschick, a functional morphologist who has studied the gecko’s climbing and clinging abilities for over 20 years. Geckos are equally at home on vertical, slanted, even backward-tilting surfaces.

“Amazingly, gecko feet can be applied and disengaged with ease, and with no sticky residue remaining on the surface,” Irschick says. These properties, high-capacity, reversibility and dry adhesion offer a tantalizing possibility for synthetic materials that can easily attach and detach heavy everyday objects such as televisions or computers to walls, as well as medical and industrial applications, among others, he and Crosby say.

This combination of properties at these scales has never been achieved before, the authors point out. Crosby says, “Our Geckskin device is about 16 inches square, about the size of an index card, and can hold a maximum force of about 700 pounds while adhering to a smooth surface such as glass.”

Beyond its impressive sticking ability, the device can be released with negligible effort and reused many times with no loss of effectiveness. For example, it can be used to stick a 42-inch television to a wall, released with a gentle tug and restuck to another surface as many times as needed, leaving no residue.

Previous efforts to synthesize the tremendous adhesive power of gecko feet and pads were based on the qualities of microscopic hairs on their toes called setae, but efforts to translate them to larger scales were unsuccessful, in part because the complexity of the entire gecko foot was not taken into account. As Irschick explains, a gecko’s foot has several interacting elements, including tendons, bones and skin, that work together to produce easily reversible adhesion.

Now he, Bartlett, Crosby and the rest of the UMass Amherst team have unlocked the simple yet elegant secret of how it’s done, to create a device that can handle excessively large weights. Geckskin and its supporting theory demonstrate that setae are not required for gecko-like performance, Crosby points out. “It’s a concept that has not been considered in other design strategies and one that may open up new research avenues in gecko-like adhesion in the future.”

The key innovation by Bartlett and colleagues was to create an integrated adhesive with a soft pad woven into a stiff fabric, which allows the pad to “drape” over a surface to maximize contact. Further, as in natural gecko feet, the skin is woven into a synthetic “tendon,” yielding a design that plays a key role in maintaining stiffness and rotational freedom, the researchers explain.

Importantly, the Geckskin’s adhesive pad uses simple everyday materials such as polydimethylsiloxane (PDMS), which holds promise for developing an inexpensive, strong and durable dry adhesive.

An amazing example of how controlling structure at the nanometer scale can provide very substantial forces at the macroscopic scale.
—James Lewis, PhD

Credit: Image courtesy of University of Texas at Austin

“Hindlimb ischemia was created in rats and treatments were delivered over seven days with an osmotic pump. The laser doppler imaging above shows the rat’s hind limb prior to treatment (on the left) and with increased blood flow (image on the right) just seven days after treatment.”

A major advantage of nanoparticles used in nanomedicine is that they can combine and deliver together more than one therapeutic component. This capability has been brought to bear in the quest to encourage regenerative blood vessel growth after ischemic disease, which causes much cardiovascular morbidity. Delivering a growth factor in a nanoparticle containing a different biomolecule as a coreceptor achieves results where delivering the factor alone had failed. A hat tip to ScienceDaily for reprinting this University of Texas at Austin news release “New Ability to Regrow Blood Vessels Holds Promise for Treatment of Heart Disease“:

University of Texas at Austin researchers have demonstrated a new and more effective method for regrowing blood vessels in the heart and limbs — a research advancement that could have major implications for how we treat heart disease, the leading cause of death in the Western world.

The treatment method developed by Cockrell School of Engineering Assistant Professor Aaron Baker could allow doctors to bypass surgery and instead repair damaged blood vessels simply by injecting a lipid-incased substance into a patient. Once inside the body, the substance stimulates cell growth and spurs the growth of new blood vessels from pre-existing ones.

The method has been tested successfully on rats, and findings of the study were published recently in the Proceedings of the National Academy of Sciences [abstract].

“Others have tried using growth factors to stimulate vessel growth in clinical trials and have not been successful,” said Baker, a faculty member in the school’s Department of Biomedical Engineering. “We think that a major reason for this is that previous methods assumed that the diseased tissues retained the ability to respond to a growth stimulus. Our method basically delivers extra components that can restore growth factor responsiveness to the tissue of patients with long-standing clinical disease.”

The ability to regrow blood vessels could prove crucial to treating chronic myocardial ischemia disease, which affects up to 27 million patients in the U.S. and leads to a reduction of blood flow in the heart and lower limbs — ultimately causing organ dysfunction and failure. …

The new method introduced by Baker and his research team builds on a promising revascularization approach that, up until now, has shown limited efficacy in clinical trials for treating human disease.

The method combines a growth factor — a substance capable of stimulating cellular growth, proliferation and cellular differentiation, as well as healing wounds — known as fibroblast growth factor 2 (FGF-2) with a lipid-embedded receptor to enhance its activity.

A challenge for scientists and engineers, however, has been getting FGF-2 to bind with cell receptors — the very molecules often found on the surface of the cell that receive chemical signals and direct activity in the cell from outside sources.

To overcome this, Baker’s method embeds the growth factors in synthetic lipid-based nanoparticles containing a coreceptor known as syndecan-4. The nanoparticles containing co-receptors that, when delivered with the growth factor, enable improved cell binding so that the growth factor can direct the targeted cell to divide, proliferate and form new cells for tissue regrowth.

The incased substance was injected into rats with hindlimb ischemia and stimulated a complete recovery from the ischemia in just seven days.

Mammalian cells are very complex mechanisms, and several decades of experience with biotechnology have demonstrated that newly discovered molecules expected to do great things often underperform expectations because changing a cell requires several molecules working together. Nanoparticles have the potential to be complex enough to accomplish what single molecules cannot.
—James Lewis, PhD

Image courtesy of Oregon State University

Nanomedicine will make major contributions to health care not only by providing new and improved therapies, but by providing new diagnostic methods that will be faster and less expensive than currently available procedures. A hat tip to KurzweilAI News for reprinting this news release from Oregon State University “Nanotube technology leading to fast, lower-cost medical diagnostics“:

Researchers at Oregon State University have tapped into the extraordinary power of carbon “nanotubes” to increase the speed of biological sensors, a technology that might one day allow a doctor to routinely perform lab tests in minutes, speeding diagnosis and treatment while reducing costs.

The new findings have almost tripled the speed of prototype nano-biosensors, and should find applications not only in medicine but in toxicology, environmental monitoring, new drug development and other fields.

The research was just reported in Lab on a Chip [abstract], a professional journal. More refinements are necessary before the systems are ready for commercial production, scientists say, but they hold great potential.

“With these types of sensors, it should be possible to do many medical lab tests in minutes, allowing the doctor to make a diagnosis during a single office visit,” said Ethan Minot, an OSU assistant professor of physics. “Many existing tests take days, cost quite a bit and require trained laboratory technicians.

“This approach should accomplish the same thing with a hand-held sensor, and might cut the cost of an existing $50 lab test to about $1,” he said.

The key to the new technology, the researchers say, is the unusual capability of carbon nanotubes. An outgrowth of nanotechnology, which deals with extraordinarily small particles near the molecular level, these nanotubes are long, hollow structures that have unique mechanical, optical and electronic properties, and are finding many applications.

In this case, carbon nanotubes can be used to detect a protein on the surface of a sensor. The nanotubes change their electrical resistance when a protein lands on them, and the extent of this change can be measured to determine the presence of a particular protein – such as serum and ductal protein biomarkers that may be indicators of breast cancer.

The newest advance was the creation of a way to keep proteins from sticking to other surfaces, like fluid sticking to the wall of a pipe. By finding a way to essentially “grease the pipe,” OSU researchers were able to speed the sensing process by 2.5 times.

Further work is needed to improve the selective binding of proteins, the scientists said, before it is ready to develop into commercial biosensors.

“Electronic detection of blood-borne biomarker proteins offers the exciting possibility of point-of-care medical diagnostics,” the researchers wrote in their study. “Ideally such electronic biosensor devices would be low-cost and would quantify multiple biomarkers within a few minutes.”

The above news item indicates not only how nanotechnology is going to improve medical care, but it hints at the future economic impact of widespread nanotechnology. If a five-minute test using a handheld biosensor in the doctor’s office replaces several expensive lab tests performed by skilled technicians, what happens to the jobs of those technicians? Historically technological innovation has created more and better jobs than those that were lost, and in this case the expanding nanotechnology industry may create jobs for the displaced medical lab technicians. But it is not at all clear that this trend will persist with the more radical displacements that will occur as nanotechnology advances toward productive nanosystems and atomically precise manufacturing. As early as 1986 in Engines of Creation Eric Drexler described how advanced nanotechnology and artificial intelligence could produce a world of abundance with no need of human labor and proposed an Inheritance Day to distribute the wealth. Three years ago here on Nanodot J Storrs Hall described how artificial general intelligence could produce an “early retirement” for the human race (see “Early retirement” and “Early retirement — how soon?“). Perhaps the issue of how transformative technologies will affect jobs, employment, and the distribution of wealth deserves more attention.
—James Lewis, PhD

Christopher William Ince Jr. writes about the role of carbon nanotubes in providing superior materials for the wind energy industry:

A major problem plaguing the wind energy industry is the inability of current manufacturing materials used in wind turbine blades to keep up with increasing demand. Dr. Usama Younes and Dr. Serkan Unal of Bayer MaterialScience LLC plan to release the results of a study recently conducted by Bayer on its development of polyurethane turbine blades designed to withstand increased stress. The study discusses how the properties of carbon nanotubes improves the fracture toughness of the materials used in the blades. According to Dr. Younes,

“Incorporation of a small amount of multi-walled carbon nanotubes improves the fracture of both polyurethane and epoxy composites by as much as 48 percent. The addition of carbon nanotubes is a viable option to improve the strength of wind turbine blades.”

This development was made possible by a grant from the Department of Energy for the purposes of comparing current materials with newer polyurethane systems as well as for the development of stronger composites for turbine blades.

Source: Azonano. (2012). Carbon Nanotubes Improve Fracture Toughness of Polyurethane Composites for Wind Turbine Blades.

Respectfully,
Christopher William Ince Jr.

Image courtesy of The University of Sheffield, project leader Professor John Rodenburg, of the University of Sheffield´s Department of Electronic and Electrical Engineering

Although not visible at this magnification, the high resolution image in the open access research publication clearly shows the gold atoms, with a spacing of 0.236 nm between atomic planes.

In his famous visionary 1959 talk in which he described molecular machines building with atomic precision, Feynman suggested that if physicists wanted to help biologists, they should improve the electron microscope by a hundred times to see individual atoms. Many improvements have been made over the years, such as aberration-correcting electron lenses, but a recent contribution from the University of Sheffield has succeeded in showing for the first time that it is possible to recover the complex exit wave from a diffraction image at atomic resolution, over a wide field of view, and using low-energy electrons. A hat tip to ScienceDaily for reprinting this University of Sheffield news release “Scientists revolutionise electron microscope“:

For over 70 years, transmission electron microscopy (TEM), which `looks through´ an object to see atomic features within it, has been constrained by the relatively poor lenses which are used to form the image.

The new method, called electron ptychography, dispenses with the lens and instead forms the image by reconstructing the scattered electron-waves after they have passed through the sample using computers.

Scientists involved in the scheme consider their findings to be a `first step´ in a `completely new epoch of electron imaging´. The process has no fundamental experimental boundaries and it is thought it will transform sub-atomic scale transmission imaging.

Project leader Professor John Rodenburg, of the University of Sheffield´s Department of Electronic and Electrical Engineering, said: “To understand how material behaves, we need to know exactly where the atoms are. This approach will enable us to look at how atoms sit next to one another in a solid object as if we´re holding them in our hands.

“We´ve shown we can improve upon the resolution limit of an electron lens by a factor of five. An extension of the same method should reach the highest resolution transmission image ever obtained; about one tenth of an atomic diameter. No longer does TEM have to be bound by the paradigm of the lens, its Achilles´ heel since its invention in 1933.” …

Professor Rodenburg added: “We measure diffraction patterns rather than images. What we record is equivalent to the strength of the electron, X-ray or light waves which have been scattered by the object – this is called their intensity. However, to make an image, we need to know when the peaks and troughs of the waves arrive at the detector – this is called their phase.

“The key breakthrough has been to develop a way to calculate the phase of the waves from their intensity alone. Once we have this, we can work out backwards what the waves were scattered from: that is, we can form an aberration-free image of the object, which is much better than can be achieved with a normal lens.

“A typical electron or X-ray microscope image is about one hundred times more blurred than the theoretical limit defined by the wavelength. In this project, the eventual aim is to get the best-ever pictures of individual atoms in any structure seen within a three-dimensional object.” …

The research was published in Nature Communications as an open access article “Ptychographic electron microscopy using high-angle dark-field scattering for sub-nanometre resolution imaging“. Although the image in the press release (above) of the gold particles is too low a magnification to see the rows of atoms, the high resolution version of the image in the research paper clearly shows the gold atoms, with a spacing of 0.236 nm between atomic planes. Additional information is available on the authors’ project web site “Welcome to the ΠΦ project“.
—James Lewis