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Nanodot: the original nanotechnology weblog

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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Surface assisted self-assembly of DNA origami nanostructures

Posted by Jim Lewis on October 26th, 2015

Credit: Suzuki et al. Institute for Integrated Cell-Material Sciences, Kyoto University.

The frequent improvements and extensions of scaffolded DNA origami testify to the usefulness of this technology. A hat tip to KurzweilAI for reporting this advance from Kyoto University organizing DNA origami nanostructures into micrometer-scale 2D arrays “Using DNA origami to build nanodevices of the future“:

Scientists have developed a method, using a double layer of lipids, which facilitates the assembly of DNA origami units, bringing us one-step closer to organized DNA nanomachines.

Scientists have been studying ways to use synthetic DNA as a building block for smaller and faster devices. DNA has the advantage of being inherently “coded”. Each DNA strand is formed of one of four “codes” that can link to only one complementary code each, thus binding two DNA strands together. Scientists are using this inherent coding to manipulate and “fold” DNA to form “origami nanostructures”: extremely small two- and three-dimensional shapes that can then be used as construction material to build nanodevices such as nanomotors for use in targeted drug delivery inside the body.

Despite progress that has been made in this field, assembling DNA origami units into larger structures remains challenging.

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Free online edition of The Feynman Lectures on Physics

Posted by Jim Lewis on October 25th, 2015

Richard P. Feynman (1918-1988)

Free to read online edition of The Feynman Lectures on Physics

A core component of Foresight’s founding vision is Richard Feynman’s 1959 talk “There’s Plenty of Room at the Bottom” in which he envisioned tiny machines building complex products with atomic precision. “Put the atoms down where the chemist says, and so you make the substance,” Feynman said. Foresight annually awards the Foresight Institute Feynman Prizes: Experimental and Theory “to researchers whose recent work have most advanced the achievement of Feynman’s goal for nanotechnology: the construction of atomically-precise products through the use of molecular machine systems.” Besides sharing a Nobel Prize for Physics Richard Feynman was also well-known as an exceptionally effective teacher. A year ago we were privileged to communicate the availability, through the efforts of Mr. John Neer, of 400 hours of Richard Feynman’s Hughes Lectures. An article on The Smithsonian publicizes the free to read online edition of The Feynman Lectures on Physics, long recognized as the definitive physics textbook. Since well-understood physical law is the foundation for the expectation that High-Throughput Atomically Precise Manufacturing is feasible, a sound understanding of basic physics provides an excellent foundation for thinking about the future of technology. Now arguably the best resources toward that understanding are available online for free.
—James Lewis, PhD

Conference video: New Methods of Exploring, Analyzing, and Predicting Molecular Interactions

Posted by Jim Lewis on October 8th, 2015

Credit: Art Olson

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 second speaker at the Computation and Molecular Nanotechnolgies session, Art Olson, presented “New Methods of Exploring, Analyzing, and Predicting Molecular Interactions” . – video length 46:17. Prof. Olson began with three simple points on interacting with and understanding the nanoscale world: (1) human interaction—how we understand something that we can’t see directly; (2) how we integrate data from lots of different sources to form a picture of what is happening at the nanoscale; (3) how we develop software tools to move forward in these areas.

Olson recommended that we should use all of our senses as much as we can because we learn in different ways; we see in different ways; we understand in different ways. Similarly, there is no one data source that gives us a complete picture of the molecular world, so we have to synthesize across scales, and we have to synthesize across methods. With software, collaboration is important, because if we can bridge disciplines rather than reinvent what already exists, we can move a lot faster.

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Foresight co-founder on the future of the human lifespan

Posted by Jim Lewis on October 6th, 2015

Credit: The Optimized Geek and Stephan Spencer

The October 1, 2015 podcast of The Optimized Geek: Reboot Your Life, with host SEO expert, author, and professional speaker Stephan Spencer featured Foresight Co-Founder and Past President Christine Peterson: A Glimpse at the Future Lifespan of Humans (55 minutes).

Christine explained the development of nanotechnology in three stages. Currently we are moving from the first stage focus on nanomaterials, like stain-resistant pants, into the second phase, dominated by nanoscale devices. The most exciting change will come with the third stage, in which systems of molecular machines will operate with atomic precision.

In responding to a question from Spencer on what we might see in the next ten years, Peterson suggested that although nanotechnology in that time frame would still be mostly about nanomaterials and simple nanodevices, one of the most interesting applications would be in health, giving the example of more effective diagnosis, imaging, and treatment of cancer through the enhanced targeting specificity of nanomaterials and nanodevices.

What might advanced nanotechnology look like 30 years from now? Peterson began with the question: What limits do the laws of physics set on what we can build with systems of molecular machines able to build with atomic precision, including inside the human body? One of many applications would be correcting DNA mistakes and mutations cell by cell. Other targets could be damaged proteins and plaques from Alzheimers, etc.

With this level of technology, lifespans would not be limited by aging or traditional diseases, but only by accidents that destroyed the brain, leading to estimated lifespans on the order of 10,000 years. With technology to record the molecular structure of brain, back-up copies of individual brains could be made, eliminating even the 10,000 year limit.

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Nanotechnology carries gene editing package into cells

Posted by Jim Lewis on October 2nd, 2015

Credit: North Carolina State University

DNA nanotechnology has been used to deliver to a cell, not just drug molecules, but an entire gene editing system. A hat tip to Bioscience Technology for reprinting this news release from North Carolina State University “Researchers Use DNA ‘Clews’ to Shuttle CRISPR-Cas9 Gene-Editing Tool into Cells“:

Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have for the first time created and used a nanoscale vehicle made of DNA to deliver a CRISPR-Cas9 gene-editing tool into cells in both cell culture and an animal model.

The CRISPR-Cas system, which is found in bacteria and archaea, protects bacteria from invaders such as viruses. It does this by creating small strands of RNA called CRISPR RNAs, which match DNA sequences specific to a given invader. When those CRISPR RNAs find a match, they unleash Cas9 proteins that cut the DNA. In recent years, the CRISPR-Cas system has garnered a great deal of attention in the research community for its potential use as a gene editing tool – with the CRISPR RNA identifying the targeted portion of the relevant DNA, and the Cas protein cleaving it.

But for Cas9 to do its work, it must first find its way into the cell. This work focused on demonstrating the potential of a new vehicle for directly introducing the CRISPR-Cas9 complex – the entire gene-editing tool – into a cell.

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DNA nanotechnology guides assembling cells into 'Organoids'

Posted by Jim Lewis on September 30th, 2015

Credit: Todhunter et al. and Nature Methods

Our principal interest in DNA nanotechnology is based on using the easily coded molecular recognition properties of DNA to arrange molecules and other nanometer scale structures; however, DNA is also proving useful for arranging whole cells for a new branch of nanomedicine: the three-dimensional printing of human tissue. A hat tip to Bioscience Technology for reprinting this University of California at San Francisco news release written by Nicholas Weiler “DNA-Guided 3-D Printing of Human Tissue is Unveiled“:

Technique Produces ‘Organoids’ Useful in Cancer Research, Drug Screening

A UCSF-led team has developed a technique to build tiny models of human tissues, called organoids, more precisely than ever before using a process that turns human cells into a biological equivalent of LEGO bricks. These mini-tissues in a dish can be used to study how particular structural features of tissue affect normal growth or go awry in cancer. They could be used for therapeutic drug screening and to help teach researchers how to grow whole human organs.

The new technique — called DNA Programmed Assembly of Cells (DPAC) and reported in the journal Nature Methods [abstract, PDF courtesy of Prof. Gartner's publications page] — allows researchers to create arrays of thousands of custom-designed organoids, such as models of human mammary glands containing several hundred cells each, which can be built in a matter of hours.

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Catalytic micromotors demonstrate carbon dioxide removal from water

Posted by Jim Lewis on September 29th, 2015

Image credit: Laboratory for Nanobioelectronics, UC San Diego Jacobs School of Engineering.

Visionary proposals for advanced medical nanorobots often picture µm scale submarine-like devices navigating the bloodstream. Those are probably still a couple decades away, but prototypes of conceptually much simpler six µm scale motors that could someday navigate the oceans to sequester carbon dioxide have been demonstrated. A hat tip to Science Daily for reprinting this news release from the University of California at San Diego Jacobs School of Engineering”Tiny carbon-capturing motors may help tackle rising carbon dioxide levels“:

Machines that are much smaller than the width of a human hair could one day help clean up carbon dioxide pollution in the oceans. Nanoengineers at the University of California, San Diego have designed enzyme-functionalized micromotors that rapidly zoom around in water, remove carbon dioxide and convert it into a usable solid form.

The proof of concept study represents a promising route to mitigate the buildup of carbon dioxide, a major greenhouse gas in the environment, said researchers. The team, led by distinguished nanoengineering professor and chair Joseph Wang, published the work this month in the journal Angewandte Chemie [abstract].

“We’re excited about the possibility of using these micromotors to combat ocean acidification and global warming,” said Virendra V. Singh, a postdoctoral scientist in Wang’s research group and a co-first author of this study.

In their experiments, nanoengineers demonstrated that the micromotors rapidly decarbonated water solutions that were saturated with carbon dioxide. Within five minutes, the micromotors removed 90 percent of the carbon dioxide from a solution of deionized water. The micromotors were just as effective in a sea water solution and removed 88 percent of the carbon dioxide in the same timeframe.

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Atomically precise boron doping of graphene nanoribbons

Posted by Jim Lewis on September 28th, 2015

Graphene nanoribbon under the microscope. Credit: University of Basel

Even without a general method for high throughput atomically precise manufacturing, atomic precision in nanotechnology is proving increasingly useful across a range of technologies. One recent example is the atomically controlled boron-doping of graphene nanoribbons. A hat tip to Science Daily for reprinting this University of Basel news release “Successful Boron-Doping of Graphene Nanoribbon“:

Physicists at the University of Basel succeed in synthesizing boron-doped graphene nanoribbons and characterizing their structural, electronic and chemical properties. The modified material could potentially be used as a sensor for the ecologically damaging nitrogen oxides, scientists report in the latest issue of Nature Communications ["Atomically controlled substitutional boron-doping of graphene nanoribbons" OPEN ACCESS].

Graphene is one of the most promising materials for improving electronic devices. The two-dimensional carbon sheet exhibits high electron mobility and accordingly has excellent conductivity. Other than usual semiconductors, the material lacks the so-called band gap, an energy range in a solid where no electron states can exist. Therefore, it avoids a situation in which the device is electronically switched off. However, in order to fabricate efficient electronic switches from graphene, it is necessary that the material can be switched “on” and “off”.

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Parallel to protein folding improves DNA origami process

Posted by Jim Lewis on September 27th, 2015

Credit: University of Oxford

Frequently we report here the use of DNA origami, a large subset of DNA nanotechnology, as a way to build and organize increasingly complex nanostructures, both to advance specific current applications and to build a path toward atomic precision in manufacturing. Despite the impressive track record of this technology, there may be opportunities to substantially improve it, as reported recently at From “Unfolding the mysteries of DNA origami“:

Experiments performed by a University of York physicist have provided new insights into how DNA assembles into nanostructures, paving the way for more precise use in technology and medicine.

Dr Katherine Dunn, now a Research Associate in the Intelligent Systems Group in the Department of Electronics at York, presents her findings in a paper published in Nature [abstract]. It describes how Dr Dunn’s experiments at Oxford demonstrated that DNA strands could not only self-assemble, but, in doing so, they follow distinct and identifiable pathways.

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Review of artificial molecular machines and their controlled motions

Posted by Jim Lewis on September 18th, 2015

Credit: Leigh research group, University of Manchester

Two weeks ago, a post about a recent overview of molecular machines included this reference:

One of the earliest reviews of artificial molecular machines, and arguably the most comprehensive, titled “Synthetic Molecular Motors and Mechanical Machines” [abstract] was published in December 2006, written by Prof. Leigh in collaboration with Euan R. Kay and Francesco Zerbetto, and was recommended here by Christine Peterson.

A few days after that post, Prof. Leigh and current colleagues Sundus Erbas-Cakmak, Charlie T. McTernan, and Alina L. Nussbaumer published in the American Chemical Society journal Chemical Reviews an updated and comparably comprehensive review titled “Artificial Molecular Machines” [abstract]. Unfortunately, at this writing, it only seems to exist behind a pay wall. At 64 MB and 126 pages, it is more like a small textbook than a review, so the size of the article is at least commensurate with the $35 fee.

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Conference video: Bringing Computational Programmability to Nanostructured Surfaces

Posted by Jim Lewis on September 11th, 2015

Credit: Alex Wissner-Gross

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 first speaker at the Computation and Molecular Nanotechnolgies session, Alex Wissner-Gross, presented “Bringing Computational Programmability to Nanostructured Surfaces” as an effort to close the feedback loop between bits and atoms. – video length 6:31. Dr. Wissner-Gross observed that, looking at the past few decades, the progress on the “bits” side of technology has been unrelenting, and that it is incumbent upon nanotechnologists to make sure that the atoms side of the story is equally compelling. Looking at the progress of civilization over the past several millennia, Dr. Wissner-Gross argued that all of the progress has been defined by our ability to increasingly, finely, and programmably tune the properties of matter in our physical world. Taken to its logical completion, one could say the ultimate form of universal programmability is the substrate for computation. He proposed that exploring the interplay between programmable atoms and programmable bits will ultimately define the critical path toward some of the most interesting technologies likely to appear over the next few decades.

One way of approaching this is to look at a brief history of time. Starting with some natural examples of programmable matter, like ribozymes, ribosomes, polyketides, and immune systems. Starting in the 15th century, artificial forms of programmable matter blend the interface between bits and matter, starting with moveable type, phonographs, universal Turing machines, and transistors. One additional very important development is the transmission of the first Internet packet, which was arguably the official decoupling of bits from atoms. Dr. Wissner-Gross then asked, how do we start to re-couple bits and atoms now that bits have made so much progress? How can we help atoms to catch up?

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Addressable molecular machines arranged in a porous crystal

Posted by Jim Lewis on September 10th, 2015

Schematic of the approach to organizing rotaxanes inside the channels of a metal–organic framework. Credit: (c) 2015 PNAS doi: 10.1073/pnas.1514485112

The artificial molecular machines overview we pointed to last week included several significant recent developments that we had missed, including this about molecular machines organized within a metal-organic framework, from the research group of 2007 Foresight Feynman Prize winner for the Experimental category J. Fraser Stoddart and his collaborators. Two months ago we described here a similar advance by a Canadian group immobilizing a molecular shuttle in a metal organic framework. The difference in the approach taken by the Loeb research group at the University of Windsor and the Stoddart research group at Northwestern University and their collaborators is very nicely explained in an article by Heather Zeiger at “Solid-state molecular switches using redox active molecules in a porous crystal“:

A group of researchers have provided a proof-of-concept procedure for making a solid-state molecular-sized switch. They combined a mechanically interlocked molecule with a pre-synthetized metal-organic framework (MOF).

Mechanically interlocked molecules have several features that make them ideal candidates for molecular switches. These interlocked molecules, known as rotaxanes or catenanes, typically involve two molecular components that have distinct orientations based on interactions between them. Scientists can control which orientation the interlocked molecules take using stimuli, such as electrochemical potential or light. Redox active interlocked molecules are compelling candidates for a molecular switch. However, in solution, these molecules are unpredictable, and when it comes to designing circuitry, controlling the molecular switch is vital.

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Overview of molecular machines documents recent progress

Posted by Jim Lewis on September 4th, 2015

Credit: Loeb Research Group, University of Windsor. One of a number of types of molecular machines included in a recent Nature overview.

Since advanced nanotechnology will be primarily about complex systems of artificial molecular machines, it is very nice to see the journal Nature begin the month with a very useful overview of molecular machines, presented as a News Feature written by Mark Peplow “The tiniest Lego: a tale of nanoscale motors, rotors, switches and pumps“:

The robot moves slowly along its track, pausing regularly to reach out an arm that carefully scoops up a component. The arm connects the component to an elaborate construction on the robot’s back. Then the robot moves forward and repeats the process — systematically stringing the parts together according to a precise design.

It might be a scene from a high-tech factory — except that this assembly line is just a few nanometres long. The components are amino acids, the product is a small peptide and the robot, created by chemist David Leigh at the University of Manchester, UK, is one of the most complex molecular-scale machines ever devised.

We commented on this advance in January 2013. Returning to the Nature review:

It is not alone. Leigh is part of a growing band of molecular architects who have been inspired to emulate the machine-like biological molecules found in living cells — kinesin proteins that stride along the cell’s microscopic scaffolding, or the ribosome that constructs proteins by reading genetic code. Over the past 25 years, these researchers have devised an impressive array of switches, ratchets, motors, rods, rings, propellers and more — molecular mechanisms that can be plugged together as if they were nanoscale Lego pieces. And progress is accelerating, thanks to improved analytical-chemistry tools and reactions that make it easier to build big organic molecules.…

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Nanotechnology provides sensors for liver-on-chip drug testing

Posted by Jim Lewis on September 2nd, 2015

Hebrew University liver-on-chip device. Photo credit: Yaakov Nahmias / Hebrew University

One of the indirect ways in which nanotechnology is impacting medical research, in synergy with biotechnology, is by enabling a “liver-on-chip” replacement for animal testing. A hat tip to Nanotechnology Now for reprinting this news release from Hebrew University “Israeli-German Partnership Aims To Replace Animal Experiments With Advanced Liver-On-Chip Devices“:

Safety evaluation is a critical part of drug and cosmetic development. In recent years there is a growing understanding that animal experiments fail to predict the human response. This necessitates the development of alternative models to predict drug toxicity.

The recent tightening of European regulations preventing the cosmetic industry from using animals in research and development, blocks companies like L’Oréal and Estée Lauder from developing new products, bringing massive investment into this field.

The main challenge in replacing animal experiments is that human cells seldom survive more than a few days outside the body. To address this challenge, scientists at The Hebrew University of Jerusalem and the Fraunhofer Institute for Cell Therapy and Immunology in Germany partnered to create a liver-on-chip device mimicking human physiology.

“The liver organs we created were less than a millimeter in diameter and survive for more than a month,” said Professor Yaakov Nahmias, the study’s lead author and Director of the Alexander Grass Center for Bioengineering at The Hebrew University.

While other groups showed similar results, the breakthrough came when the groups added nanotechnology-based sensors to the mix. “We realized that because we are building the organs ourselves, we are not limited to biology, and could introduce electronic and optical sensors to the tissue itself. Essentially we are building bionic organs on a chip,” said Nahmias.

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Macroscopic mechanical manipulation controls molecular machine array

Posted by Jim Lewis on September 1st, 2015

Pliers representing amphipathic binaphthyl (left), chemical formula of amphipathic binaphthyl (center), and three-dimensional conformation of amphipathic binaphthyl. Credit: NIMS MANA

Current nanotechnology is about nanomaterials, nanodevices, and simple molecular machines. Advanced nanotechnology will largely be about complex systems of artificial molecular machines, rather as life can be described as complex systems of biological molecular machines. So any new insight about molecular machines is of potential interest as a signpost toward advanced nanotechnology. A hat tip to AZO NANO for reprinting this press release from Japan’s National Institute for Materials Science “Motion of Supramolecular Machines Successfully Controlled through Simple Mechanical Manipulation“:

NIMS MANA researchers found that molecular machines can be easily manipulated using very small mechanical energy, taking advantage of the property that they aggregate on the surface of water. This study was published in the online version of the German Chemical Society’s journal “Angewandte Chemie International Edition” on June 12, 2015. (D. Ishikawa, T. Mori, Y. Yonamine, W. Nakanishi, D. L. Cheung, J. P. Hill, and K. Ariga “Mechanochemical tuning of binaphthyl conformation at the air-water interface” Angew. Chem. Int. Ed., DOI: 10.1002/anie.201503363)

MANA Scientist Waka Nakanishi and other researchers at the Supermolecules Unit (Katsuhiko Ariga, director) of the NIMS International Center for Materials Nanoarchitectonics (MANA), in collaboration with Dr. David Cheung at the University of Strathclyde (UK), found that molecular machines (molecules capable of mechanical movement) can be easily manipulated using very small mechanical energy, taking advantage of the property that they aggregate on the surface of water. Our findings are expected to contribute to the development of basic technology for the operation of various molecular machines that have been studied for their application as sensor and other types of devices.

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Femtosecond imaging with near nanometer spatial resolution

Posted by Jim Lewis on August 31st, 2015

Three-dimensional rendering of surface features imaged by ptychographic coherent diffractive imaging. (Source: University of Colorado). The surface shown is a portion of Fig. 4a. Judging from the scale bar in the scanning electron micrograph of this surface shown in Fig. 1b, the inner diameter of the circle is about 10 µm (10,000 nm).

As we noted back in April, Richard Feynman in his classic 1959 talk challenged his fellow physicists to make the electron microscope 100 times better. A “new super powerful electron microscope that can pinpoint the position of single atoms” had been unveiled at a facility in the UK. While that SuperSTEM is one of only three in the world, a recently demonstrated technology based upon “tabletop extreme-ultraviolet ptychography” brings complementary nanometer-scale resolution to a much smaller (and presumably less expensive) instrument. A hat tip to John Faith for bringing this EETimes article by R Colin Johnson to our attention “EUV Breaks Through to Angstrom“:

The wavelength of visible light — 400-to-700 nanometers — makes it impossible with today’s tools to take photographs of nanoscale objects with any sort of reasonable resolution. The answer has been to use scanning electron microscopy (SEM) and atomic force microscopy (ATM), which yield reasonable images. These tools, however, produce nothing close to the angstrom-level (tenth of a nanometer) resolution of a new type of microscope that uses femtosecond pulses of extreme ultraviolet light (EUV) — the same wavelength light to be used for sub-10 nanometer semiconductor lithography.] …

The claim made here of angstrom-level resolution appears to be a substantial overstatement of the published result (see below). Nevertheless, the technique does appear to offer substantial advantages, and may approach this resolution in the near future.

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A tunable bandgap by doping a few atomic layers of black phosphorous

Posted by Jim Lewis on August 29th, 2015

Phosphorene (with in-situ deposition of potassium (K) atoms to induce doping) – The natural successor to Graphene? Credit: Institute for Basic Science

The process of finding novel arrangements of atoms with interesting and useful properties does not appear to be slowing. A hat tip to ScienceDaily for reprinting this news release from the Institute for Basic Science, Korea “Black Phosphorus (BP) Surges Ahead of Graphene“:

A Korean team of scientists tune BP’s band gap to form a superior conductor, allowing for the application to be mass produced for electronic and optoelectronics devices

The research team operating out of Pohang University of Science and Technology (POSTECH), affiliated with the Institute for Basic Science’s (IBS) Center for Artificial Low Dimensional Electronic Systems (CALDES), reported a tunable band gap in BP, effectively modifying the semiconducting material into a unique state of matter with anisotropic dispersion. This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.

To truly understand the significance of the team’s findings, it’s instrumental to understand the nature of two-dimensional (2-D) materials, and for that one must go back to 2010 when the world of 2-D materials was dominated by a simple thin sheet of carbon, a layered form of carbon atoms constructed to resemble honeycomb, called graphene. Graphene was globally heralded as a wonder-material thanks to the work of two British scientists who won the Nobel Prize for Physics for their research on it.

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