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Conference video: Nanoscale Materials, Devices, and Processing Predicted from First Principles

Posted by Jim Lewis on January 15th, 2016

Credit: William Goddard

A select set of videos from the 2013 Foresight Technical Conference: Illuminating Atomic Precision, held January 11-13, 2013 in Palo Alto, have been made available on vimeo. Videos have been posted of those presentations for which the speakers have consented. Other presentations contained confidential information and will not be posted.

The seventh speaker at the Computation and Molecular Nanotechnolgies session, William Goddard, presented “Nanoscale Materials, Devices, and Processing Predicted from First Principals”. – video length 34:22. Prof. Goddard addressed some of the method developments to allow modeling of large-scale systems, followed by some examples. He noted that the grand vision over the past 25 years has been that theory can be used to predict something useful. To predict new systems where there is no empirical data it is necessary to start with first principles.

Prof Goddard reviewed the advances that enabled going from first principles to nanoscopic systems of interest. Starting from quantum mechanics to describe a few hundred—perhaps a thousand—atoms, it was necessary to describe realistic temperatures, pressures, and concentrations in systems with millions or billions of atoms.

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Conference video: Mythbusting Knowledge Transfer Mechanisms through Science Gateways

Posted by Jim Lewis on January 14th, 2016

Credit: Gerhard Klimeck

A select set of videos from the 2013 Foresight Technical Conference: Illuminating Atomic Precision, held January 11-13, 2013 in Palo Alto, have been made available on vimeo. Videos have been posted of those presentations for which the speakers have consented. Other presentations contained confidential information and will not be posted.

The fifth speaker at the Computation and Molecular Nanotechnolgies session, Gerhard Klimeck, presented “Mythbusting Knowledge Transfer Mechanisms through Science Gateways” . – video length 40:28. Prof. Klimeck addressed novel ways to disseminate nanotechnology simulations to broader audiences using as an example a user facility, the web site nanoHUB. About 12,000 users sign up for accounts and run half a million simulations throughout the year. Even more people view lectures, seminars, tutorials, for which no account is needed. Looking at a display of the use of the facility from day to day, Prof. Klimeck asked whether the bursts of activity that appear show signs of knowledge transfer happening. Some of this data illustrates the mythbusting over the past ten years—all the things we were told we could not do. For example, the facility used to have about a thousand users per year, and then the tools were made interactive and suddenly that grew to about 12,000 today. Lectures and seminars were introduced and led to dramatic growth. Citing recent interest in MOOCs (massive open online course), Prof. Klimeck noted that they had been a MOOC for a number of years.

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DNA nanotechnology controls which molecules enter cells

Posted by Jim Lewis on January 13th, 2016

Lock and key mechanism (courtesy of Dr Stefan Howorka and Dr Jonathan Burns, UCL)

A useful addition to the toolkits for nanomedicine and synthetic biology would be a cell membrane pore to exclude or admit predetermined molecules on demand. A hat tip to Kurzweil Accelerating Intelligence for describing and pointing to this UCL news release “DNA ‘building blocks’ pave the way for improved drug delivery“:

DNA has been used as a ‘molecular building block’ to construct synthetic bio-inspired pores which will improve the way drugs are delivered and help advance the field of synthetic biology, according to scientists from UCL and Nanion Technologies.

The study, published today in Nature Nanotechnology [abstract] and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), Leverhulme Trust and UCL Chemistry, shows how DNA can be used to build stable and predictable pores that have a defined shape and charge to control which molecules can pass through the pore and when.

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Molecular arm grabs, transports, releases molecular cargo

Posted by Jim Lewis on January 12th, 2016

Cartoon representation of a small-molecule robot able to transport a molecular cargo (shown in red) in either direction from blue-to-green or green-to-blue platform sites. Credit: Leigh Group, University of Manchester

A few months ago we pointed to a very thorough review of artificial molecular machines authored by Prof. David Leigh (winner of the 2007 Feynman Prize in Nanotechnology, Theory category) and three colleagues. Over at ChemistryWorld Simon Hadlington describes recent work from Prof. Leigh’s group using a molecular robot arm to pick up, transport, and release a molecular cargo. “Molecular robot opens the way to nano-assembly lines“:

UK chemists have devised a nanoscale robot that can grasp a cargo molecule, pick it up, place it in a new position some distance away and release it. At no time does the cargo dissociate from the machine or exchange with other molecules. While such a sequence of actions is trivial on a macroscopic scale, to achieve it synthetically with small molecules is unprecedented and could mark the start of a new era of molecular robotics. Multiple similar robots in sequence could, for example, replicate a factory’s assembly line to build increasingly complex molecular structures. …

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Electron tomography reveals precise positions of individual atoms in aperiodic material

Posted by Jim Lewis on January 11th, 2016

The scientists were able to plot the exact coordinates of nine layers of atoms with a precision of 19 trillionths of a meter. Credit: Mary Scott and Jianwei (John) Miao/UCLA

As researchers work to build increasingly complex structures and devices to atomic precision, it will become increasingly useful to be able to image arbitrarily complex 3D nanostructures to atomic precision. This was a challenge that Richard Feynman threw out to electron microscopists in 1959, and UCLA scientists appear to have decisively met Feynman’s challenge. A hat tip to Science Daily for reprinting this UCLA news release written by Katherine Kornei “UCLA physicists determine the three-dimensional positions of individual atoms for the first time“:

Finding will help scientists better understand the structural properties of materials

Atoms are the building blocks of all matter on Earth, and the patterns in which they are arranged dictate how strong, conductive or flexible a material will be. Now, scientists at UCLA have used a powerful microscope to image the three-dimensional positions of individual atoms to a precision of 19 trillionths of a meter, which is several times smaller than a hydrogen atom.

Their observations make it possible, for the first time, to infer the macroscopic properties of materials based on their structural arrangements of atoms, which will guide how scientists and engineers build aircraft components, for example. The research, led by Jianwei (John) Miao, a UCLA professor of physics and astronomy and a member of UCLA’s California NanoSystems Institute, is published Sept. 21 in the online edition of the journal Nature Materials [abstract].

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Nanoparticles ameliorate MS in mice by inducing immune tolerance of myelin

Posted by Jim Lewis on January 7th, 2016

The cerebellum from an animal early in the demyelinating phase of the late-onset disease. The green marks myelinated axons and the red highlights areas of inflammation and demyelination. Courtesy of Maria Traka

Nanoparticles fabricated by a variety of techniques offer great hope for the development of nanomedicine. One of the potential applications for specially engineered nanoparticles is the modulation of an immune system that is targeting an essential molecule, as explained by this news release from Northwestern University written by Maria Paul “How Multiple Sclerosis Can Be Triggered By Brain Cell Death“:

Nanoparticles stop the progressive disease and are being developed for humans

Multiple sclerosis (MS) may be triggered by the death of brain cells that make the insulation around nerve fibers, a surprising new view of the disease reported in a study from Northwestern Medicine and The University of Chicago. And a specially developed nanoparticle prevented MS even after the death of those brain cells, an experiment in the study showed.

The nanoparticles are being developed for clinical trials that could lead to new treatments — without the side effects of current therapies — in adults.

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Inexpensive transparent conductors from correlated metal nanostructures

Posted by Jim Lewis on January 6th, 2016

A figure showing the crystal structure of strontium vanadate (orange) and calcium vanadate (blue). The red dots are oxygen atoms arranged in 8 octohedra surrounding a single strontium or calcium atom. Vanadium atoms can be seen inside each octahedron. Credit image: Lei Zhang/Penn State

It is usually both interesting and useful when technology identifies multiple paths to the same goal, particularly when a new path has a major advantage, such as a much lower cost and substituting an abundant resource for a limited one. A hat tip to Kurzweil Accelerating Intelligence for reprinting this Penn State news release written by Walt Mills “Transparent metal films for smartphone, tablet and TV displays“:

A new material that is both highly transparent and electrically conductive could make large screen displays, smart windows and even touch screens and solar cells more affordable and efficient, according to the Penn State materials scientists and engineers who discovered it.

Indium tin oxide, the transparent conductor that is currently used for more than 90 percent of the display market, has been the dominant material for the past 60 years. However, in the last decade, the price of indium has increased dramatically. Displays and touchscreen modules have become a main cost driver in smartphones and tablets, making up close to 40 percent of the cost. While memory chips and processors get cheaper, displays get more expensive from generation to generation. Manufacturers have searched for a possible ITO replacement, but until now, nothing has matched ITO’s combination of optical transparency, electrical conductivity and ease of fabrication.

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Active and reversible control of nanoparticle optical properties

Posted by Jim Lewis on January 3rd, 2016

This electron microscope image shows a dimer of silver plated gold nanoparticles. A layer of silver connects the particles. Credit: D. Swearer/Rice University

Nanoparticles exhibit a range of useful electronic, optical, and magnetic properties. These particles would be even more useful if such properties could be deliberately and reversibly tuned for specific purposes. Scientists have now achieved substantial progress in this direction. A hat tip to ScienceDaily for reprinting this Rice University news release written by Jade Boyd “Nanoscale drawbridges open path to color displays“:

Rice develops first method for reversible color changes with metal nanoparticles

A new method for building “drawbridges” between metal nanoparticles may allow electronics makers to build full-color displays using light-scattering nanoparticles that are similar to the gold materials that medieval artisans used to create red stained-glass.

“Wouldn’t it be interesting if we could create stained-glass windows that changed colors at the flip of a switch?” said Christy Landes, associate professor of chemistry at Rice and the lead researcher on a new study about the drawbridge method that appears this week in the open-access journal Science Advances. ["From tunable core-shell nanoparticles to plasmonic drawbridges: Active control of nanoparticle optical properties"]

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Rolling DNA-based motors increase nano-walker speeds 1000-fold

Posted by Jim Lewis on December 12th, 2015

Emory post-doctoral fellow Kevin Yehl sets up a smart-phone microscope to get a readout for the particle motion of the rolling DNA motor. This simple, low-tech method could come in handy for doing disease diagnostics in the field, for instance, detecting a single mutation in a DNA strand. Credit: Bryan Meltz, Emory Photo/Video

We have occasionally cited research in which DNA walkers move molecular components along DNA tracks. A very different approach to DNA motors has succeeded in moving micron-sized glass spheres sporting hundreds of DNA legs at 1000 times the speed of other DNA motors. A hat tip to ScienceDaily for reprinting this Emory University news article by Carol Clark “Nano-walkers take speedy leap forward with first rolling DNA-based motor“:

Physical chemists have devised a rolling DNA-based motor that’s 1,000 times faster than any other synthetic DNA motor, giving it potential for real-world applications, such as disease diagnostics. Nature Nanotechnology [abstract] is publishing the finding.

“Unlike other synthetic DNA-based motors, which use legs to ‘walk’ like tiny robots, ours is the first rolling DNA motor, making it far faster and more robust,” says Khalid Salaita, the Emory University chemist who led the research. “It’s like the biological equivalent of the invention of the wheel for the field of DNA machines.”

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Octopodal nanoparticles combine catalytic, plasmonic functions

Posted by Jim Lewis on December 11th, 2015

A scanning electron transmission microscope image shows an octopod, left, created at Rice University that has both plasmonic and catalytic abilities. At right is an illustration of the octopod, which has a gold core and a gold-palladium alloy surface. The scale bar is 50 nanometers. Courtesy of the Ringe Group/Rice University

More complex nanoparticle structures provide the opportunity to integrate multiple functions, enabling nanotechnology to play a larger role in industrial processes. A hat tip to Nanowerk for reprinting this Rice University News release “Tiny octopods catalyze bright ideas“:

Nanoscale octopods that do double duty as catalysts and plasmonic sensors are lighting a path toward more efficient industrial processes, according to a Rice University scientist.

Catalysts are substances that speed up chemical reactions and are essential to many industries, including petroleum, food processing and pharmaceuticals. Common catalysts include palladium and platinum, both found in cars’ catalytic converters. Plasmons are waves of electrons that oscillate in particles, usually metallic, when excited by light. Plasmonic metals like gold and silver can be used as sensors in biological applications and for chemical detection, among others.

Plasmonic materials are not the best catalysts, and catalysts are typically very poor for plasmonics. But combining them in the right way shows promise for industrial and scientific applications, said Emilie Ringe, a Rice assistant professor of materials science and nanoengineering and of chemistry who led the study that appears in Scientific Reports ["Resonances of nanoparticles with poor plasmonic metal tips", open access].

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Novel nanoconjugate delivers synergistic combination of microRNAs to treat cancer

Posted by Jim Lewis on December 11th, 2015

MIT researchers developed this hydrogel embedded with triple helix microRNA particles and used it to treat cancer in mice. Image: João Conde, Nuria Oliva, and Natalie Artzi

Speaking of nanomedicine, nanoparticles, microRNAs, and cancer, another research group, this time at the Broad Institute of MIT and Harvard, has demonstrated the therapeutic potential of using the right nanoconjugate to deliver the right microRNAs to tumors. A hat tip to BioScience Technology for reprinting this MIT news office release written by Anne Trafton “A new way to deliver microRNAs for cancer treatment“:

Scientists exploit gene therapy to shrink tumors in mice with an aggressive form of breast cancer.

Twenty years ago, scientists discovered that short strands of RNA known as microRNA help cells to fine-tune their gene expression. Disruption or loss of some microRNAs has been linked to cancer, raising the possibility of treating tumors by adjusting microRNA levels.

Developing such treatments requires delivering microRNA to tumors, which has proven difficult. However, researchers from MIT have now shown that by twisting RNA strands into a triple helix and embedding them in a biocompatible gel, they can not only deliver the strands efficiently but also use them to shrink aggressive tumors in mice.

Using this technique, the researchers dramatically improved cancer survival rates by simultaneously turning on a tumor-suppressing microRNA and de-activating one that causes cancer. They believe their approach could also be used for delivering other types of RNA, as well as DNA and other therapeutic molecules.

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Ultrasensitive microRNA assay with nanosensor to detect cancer

Posted by Jim Lewis on December 10th, 2015

The cancer-specific microRNA miR-10b hybridizes to DNA immobilized on a gold nanoprism. Credit: Joshi et al. ACS Nano DOI: 10.1021/acsnano.5b04527

Nanotechnology will increasingly contribute to medicine through the development of increasingly complex, computer-controlled nanorobots (such as these early DNA origami-based prototypes we cited here and here). But even very simple devices exploiting nanoparticle-based molecular interactions are looking very promising. For example, from the Indiana University-Purdue University Indianapolis Newsroom “Nanotechnology-based sensor developed to measure microRNAs in blood, speed cancer detection“:

A simple, ultrasensitive microRNA sensor developed and tested by researchers from the School of Science at Indiana University-Purdue University Indianapolis, the IU School of Medicine, and the Indiana University Melvin and Bren Simon Cancer Center holds promise for the design of new diagnostic strategies and, potentially, for the prognosis and treatment of pancreatic and other cancers.

In a study published in the November issue of ACS Nano ["Label-free nanoplasmonic-based short noncoding RNA sensing at attomolar concentrations allows for quantitative and highly specific assay of microRNA-10b in biological fluids and circulating exosomes" open access article], a peer-reviewed journal of the American Chemical Society focusing on nanoscience and nanotechnology research, the IUPUI researchers describe their design of the novel, low-cost, nanotechnology-enabled reusable sensor. They also report on the promising results from tests of the sensor’s ability to identify pancreatic cancer or indicate the existence of a benign condition by quantifying changes in levels of microRNA signatures linked to pancreatic cancer. MicroRNAs are small molecules of RNA that regulate how larger RNA molecules lead to protein expression. As such, microRNAs are very important in biology and disease states.

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Using DNA nanotechnology to position molecules with atomic precision

Posted by Jim Lewis on December 9th, 2015

Concept of a high-resolution DNA positioning device. Credit: JJ Funke & H Dietz Nature Nanotechnology doi: 10.1038/nnano.2015.240

The powerful and elegant molecular recognition code that makes possible double helical DNA has also made scaffolded DNA origami and its parent field, structural DNA nanotechnology, probably the most widespread and useful approach to bottom-up molecular nanotechnology. The 2-nm diameter of the DNA helix leads to the suspicion, however, that the ultimate precision obtainable with these technologies might not be much better than 5 nm, more than an order of magnitude less precise than atomic precision. A paper published two months ago, however, demonstrates much finer control using a DNA hinge with “adjuster helices” to control the angle of the hinge. The abstract (reference numbers omitted) from “Placing molecules with Bohr radius resolution using DNA origami“:

Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes … . It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins …. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects … and placing them in an orderly manner on solid substrates … . So far, few objects afford a design accuracy better than 5 nm … , and the subnanometre scale has been reached only within the unit cells of designed DNA crystals … . Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures … .

The Bohr radius is the most probable distance between the proton and the electron of a hydrogen atom in its ground state, and is approximately 52.9 pm (0.0529 nm). This work from Hendrik Dietz’s group at the Technical University of Munich, Germany, continues his work on dynamic nanomachines from DNA nanotechnology that we cited last spring. For additional information about the new paper, see:

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Single-molecule light-driven nanosubmarine

Posted by Jim Lewis on December 5th, 2015

Rice University scientists have created light-driven, single-molecule submersibles that contain just 244 atoms. (Illustration by Loïc Samuel/Rice University)

Recently we noted the accomplishments of James Tour, winner of the 2008 Foresight Institute Feynman Prize in the Experimental category, and his collaborators implementing a nanomaterial incorporating single-atom catalysts. Their most recent accomplishment is a single-molecule nanosubmarine. A hat tip to Nanotechnology Now for reprinting this Rice University news release “Rice makes light-driven nanosubmarine“:

Speedy single-molecule submersibles are a first

Though they’re not quite ready for boarding a lá “Fantastic Voyage,” nanoscale submarines created at Rice University are proving themselves seaworthy.

Each of the single-molecule, 244-atom submersibles built in the Rice lab of chemist James Tour has a motor powered by ultraviolet light. With each full revolution, the motor’s tail-like propeller moves the sub forward 18 nanometers.

And with the motors running at more than a million RPM, that translates into speed. Though the sub’s top speed amounts to less than 1 inch per second, Tour said that’s a breakneck pace on the molecular scale.

“These are the fastest-moving molecules ever seen in solution,” he said.

Expressed in a different way, the researchers reported this month in the American Chemical Society journal Nano Letters [abstract] that their light-driven nanosubmersibles show an “enhancement in diffusion” of 26 percent. That means the subs diffuse, or spread out, much faster than they already do due to Brownian motion, the random way particles spread in a solution.

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Atomic precision in sculpting 3-D objects

Posted by Jim Lewis on December 3rd, 2015

ORNL researchers used a new scanning transmission electron microscopy technique to sculpt 3-D nanoscale features in a complex oxide material. (credit: Department of Energy’s Oak Ridge National Laboratory)

Atomic-level sculpting of a crystalline oxide from a metastable amorphous oxide film has been demonstrated using a scanning transmission electron microscope. A hat tip to KurzweilAI for reporting this Oak Ridge National Laboratory news release “New electron microscopy method sculpts 3-D structures at atomic level“:

Electron microscopy researchers at the Department of Energy’s Oak Ridge National Laboratory have developed a unique way to build 3-D structures with finely controlled shapes as small as one to two billionths of a meter.

The ORNL study published in the journal Small demonstrates how scanning transmission electron microscopes, normally used as imaging tools, are also capable of precision sculpting of nanometer-sized 3-D features in complex oxide materials.

By offering single atomic plane precision, the technique could find uses in fabricating structures for functional nanoscale devices such as microchips. The structures grow epitaxially, or in perfect crystalline alignment, which ensures that the same electrical and mechanical properties extend throughout the whole material.

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Generating hydrogen with single atom catalysts

Posted by Jim Lewis on November 13th, 2015

Disordered graphitic carbon doped with nitrogen and augmented with cobalt atoms serves as an efficient, robust catalyst for hydrogen separation from water. The material discovered at Rice University could challenge more expensive platinum-based catalysts. (Credit: Tour Group/Rice University)

James Tour, winner of the 2008 Foresight Institute Feynman Prize in the Experimental category, and his collaborators continue to bring forward a variety of promising applications based upon graphene and other nanostructured materials. Recently we cited a nanotechnology computer memory breakthrough and before that a flexible supercapacitor from stacked nanomaterial. A hat tipp to Nanotechnology Now for reprinting this Rice University news release written by Mike Williams “Cobalt atoms on graphene a powerful combo“:

Rice University catalyst holds promise for clean, inexpensive hydrogen production

Graphene doped with nitrogen and augmented with cobalt atoms has proven to be an effective, durable catalyst for the production of hydrogen from water, according to scientists at Rice University.

The Rice lab of chemist James Tour and colleagues at the Chinese Academy of Sciences, the University of Texas at San Antonio and the University of Houston have reported the development of a robust, solid-state catalyst that shows promise to replace expensive platinum for hydrogen generation.

Catalysts can split water into its constituent hydrogen and oxygen atoms, a process required for fuel cells. The latest discovery, detailed in Nature Communications [Open Access], is a significant step toward lower-cost catalysts for energy production, according to the researchers.

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Architecture for atomically precise quantum computer in silicon

Posted by Jim Lewis on November 9th, 2015

Australian researchers have figured out a way to deal with errors in quantum computers. Credit: UNSW Australia

All applications of nanotechnology will eventually benefit from the movement of current methods of nanofabrication toward atomic precision, eventually producing a general purpose method for high throughput atomically precise manufacturing. But perhaps the first and most important application in which atomically precise fabrication will make a critically important contribution is quantum computing. Back in 2012 we noted successes of Australian researchers in atomically-precise positioning of a single atom transistor and in writing of a single-atom qubit in silicon. Also in 2012 Foresight Update reported on a workshop sponsored by the Atomically Precise Manufacturing Consortium, NIST, and Zyvex Labs to discuss the fabrication of such atomically precise devices. Now Australian researchers have provided a blueprint for operational quantum computers. A hat tip to Nanotechnology-Now for reprinting this University of New South Wales news release written by Myles Gough “Researchers design architecture for a quantum computer in silicon“:

Researchers at UNSW and the University of Melbourne have designed a 3D silicon chip architecture based on single atom quantum bits, providing a blueprint to build a large-scale quantum computer.

Australian scientists have designed a 3D silicon chip architecture based on single atom quantum bits, which is compatible with atomic-scale fabrication techniques – providing a blueprint to build a large-scale quantum computer.

Scientists and engineers from the Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology (CQC2T), headquartered at UNSW, are leading the world in the race to develop a scalable quantum computer in silicon – a material well-understood and favoured by the trillion-dollar computing and microelectronics industry.

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One-directional rotation in a new artificial molecular motor

Posted by Jim Lewis on November 5th, 2015

Credit: Feringa Group, University of Groningen

Biological molecular motors are amazing nanomachines that make all life possible, but even smaller artificial molecular motors based upon organic chemistry instead of biological polymers continue to become more complex and better controlled. A hat tip to Nanowerk for reprinting this news release from the University of Groningen in The Netherlands “New molecular motor mimics two wheels on an axle“:

University of Groningen scientists led by Professor of Organic Chemistry Ben Feringa have designed a new type of molecular motor. In contrast to previous designs, this molecule is symmetrical. It comprises two parts, which are connected by a central ‘axle’ and rotate in opposite directions, just like the wheels of a car. The results, which were published … in the journal Nature Chemistry [abstract], would be ideal for nano transport systems.

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DNA nanomachine lights up to diagnose diseases

Posted by Jim Lewis on November 2nd, 2015

The light-generating DNA antibody detecting nanomachine is illustrated here in action, bound to an antibody. Credit: Marco Tripodi

As current day nanotechnology makes incremental advances in technologies that advance the goal of atomic precision in control of the structure of matter, such as DNA nanotechnology, such advances sometimes also provide opportunities to apply primitive nanomachines to current needs. A hat tip to KurzweilAI for reporting such an advance announced by the newsroom of the Université de Montréal “Detecting HIV diagnostic antibodies with DNA nanomachines“:

New research may revolutionize the slow, cumbersome and expensive process of detecting the antibodies that can help with the diagnosis of infectious and auto-immune diseases such as rheumatoid arthritis and HIV. An international team of researchers have designed and synthesized a nanometer-scale DNA “machine” whose customized modifications enable it to recognize a specific target antibody. Their new approach, which they described this month in Angewandte Chemie [abstract], promises to support the development of rapid, low-cost antibody detection at the point-of-care, eliminating the treatment initiation delays and increasing healthcare costs associated with current techniques.

The binding of the antibody to the DNA machine causes a structural change (or switch), which generates a light signal. The sensor does not need to be chemically activated and is rapid – acting within five minutes – enabling the targeted antibodies to be easily detected, even in complex clinical samples such as blood serum.

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Chirality-assisted synthesis a new tool for nanotechnology

Posted by Jim Lewis on October 30th, 2015

Credit: Schneebeli research group, University of Vermont.

New tools that provide chemists with greater ability to build more complex molecules are important steps on the path to atomically precise manufacturing. The newsroom of the University of Vermont reports a “fundamentally new way to control the shape of molecules.” “Scientists Build Wrench 1.7 Nanometers Wide“:

Hold up your two hands. They are identical in structure, but mirror opposites. No matter how hard you try, they can’t be superimposed onto each other. Or, as chemists would say, they have “chirality,” from the Greek word for hand. A molecule that is chiral comes in two identical, but opposite, forms–just like a left and right hand.

University of Vermont chemist Severin Schneebeli has invented a new way to use chirality to make a wrench. A nanoscale wrench. His team’s discovery allows them to precisely control nanoscale shapes and holds promise as a highly accurate and fast method of creating customized molecules.

This use of “chirality-assisted synthesis” is a fundamentally new approach to control the shape of large molecules–one of the foundational needs for making a new generation of complex synthetic materials, including polymers and medicines.

The UVM team’s results were presented online, September 9, in the top-ranked chemistry journal Angewandte Chemie [abstract].

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