Tag Archives: A*STAR

Killing bacteria on contact with dragonfly-inspired nanocoating

Scientists in Singapore were inspired by dragonflies and cicadas according to a March 28, 2018 news item on Nanowerk (Note: A link has been removed),

Studies have shown that the wings of dragonflies and cicadas prevent bacterial growth due to their natural structure. The surfaces of their wings are covered in nanopillars making them look like a bed of nails. When bacteria come into contact with these surfaces, their cell membranes get ripped apart immediately and they are killed. This inspired researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR to invent an anti-bacterial nano coating for disinfecting frequently touched surfaces such as door handles, tables and lift buttons.

This technology will prove particularly useful in creating bacteria-free surfaces in places like hospitals and clinics, where sterilization is important to help control the spread of infections. Their new research was recently published in the journal Small (“ZnO Nanopillar Coated Surfaces with Substrate-Dependent Superbactericidal Property”)

Image 1: Zinc oxide nanopillars that looked like a bed of nails can kill a broad range of germs when used as a coating on frequently-touched surfaces. Courtesy: A*STAR

A March 28, 2018 Agency for Science Technology and Research (A*STAR) press release, which originated the news item, describes the work further,

80% of common infections are spread by hands, according to the B.C. [province of Canada] Centre for Disease Control1. Disinfecting commonly touched surfaces helps to reduce the spread of harmful germs by our hands, but would require manual and repeated disinfection because germs grow rapidly. Current disinfectants may also contain chemicals like triclosan which are not recognized as safe and effective 2, and may lead to bacterial resistance and environmental contamination if used extensively.

“There is an urgent need for a better way to disinfect surfaces without causing bacterial resistance or harm to the environment. This will help us to prevent the transmission of infectious diseases from contact with surfaces,” said IBN Executive Director Professor Jackie Y. Ying.

To tackle this problem, a team of researchers led by IBN Group Leader Dr Yugen Zhang created a novel nano coating that can spontaneously kill bacteria upon contact. Inspired by studies on dragonflies and cicadas, the IBN scientists grew nanopilllars of zinc oxide, a compound known for its anti-bacterial and non-toxic properties. The zinc oxide nanopillars can kill a broad range of germs like E. coli and S. aureus that are commonly transmitted from surface contact.

Tests on ceramic, glass, titanium and zinc surfaces showed that the coating effectively killed up to 99.9% of germs found on the surfaces. As the bacteria are killed mechanically rather than chemically, the use of the nano coating would not contribute to environmental pollution. Also, the bacteria will not be able to develop resistance as they are completely destroyed when their cell walls are pierced by the nanopillars upon contact.

Further studies revealed that the nano coating demonstrated the best bacteria killing power when it is applied on zinc surfaces, compared with other surfaces. This is because the zinc oxide nanopillars catalyzed the release of superoxides (or reactive oxygen species), which could even kill nearby free floating bacteria that were not in direct contact with the surface. This super bacteria killing power from the combination of nanopillars and zinc broadens the scope of applications of the coating beyond hard surfaces.

Subsequently, the researchers studied the effect of placing a piece of zinc that had been coated with zinc oxide nanopillars into water containing E. coli. All the bacteria were killed, suggesting that this material could potentially be used for water purification.

Dr Zhang said, “Our nano coating is designed to disinfect surfaces in a novel yet practical way. This study demonstrated that our coating can effectively kill germs on different types of surfaces, and also in water. We were also able to achieve super bacteria killing power when the coating was used on zinc surfaces because of its dual mechanism of action. We hope to use this technology to create bacteria-free surfaces in a safe, inexpensive and effective manner, especially in places where germs tend to accumulate.”

IBN has recently received a grant from the National Research Foundation, Prime Minister’s Office, Singapore, under its Competitive Research Programme to further develop this coating technology in collaboration with Tan Tock Seng Hospital for commercial application over the next 5 years.

1 B.C. Centre for Disease Control

2 U.S. Food & Drug Administration

(I wasn’t expecting to see a reference to my home province [BC Centre for Disease Control].) Back to the usual, here’s a link to and a citation for the paper,

ZnO Nanopillar Coated Surfaces with Substrate‐Dependent Superbactericidal Property by Guangshun Yi, Yuan Yuan, Xiukai Li, Yugen Zhang. Small https://doi.org/10.1002/smll.201703159 First published: 22 February 2018

This paper is behind a paywall.

One final comment, this research reminds me of research into simulating shark skin because that too has bacteria-killing nanostructures. My latest about the sharkskin research is a Sept, 18, 2014 posting.

Disorderly conduct amongst electrons

An Oct. 7, 2016 news item on Nanowerk highlights some research from A*STAR (Singapore’s Agency for Science and Technology Research), Note: A link has been removed,

Solid materials whose atoms are arranged in a well-ordered crystalline structure are usually better conductors of electricity than randomly structured, or amorphous, solids. Recently, however, A*STAR researchers found that iron-tellurium (FeTe) breaks this rule, displaying higher conductivity, and optical reflectivity, in the amorphous phase.

A recent study, published in the journal Acta Materialia (“Unravelling the anomalous electrical and optical phase-change characteristics in FeTe”), describes their efforts to understand why FeTe’s behavior is counterintuitive to expectations.

Iron-tellurium conducts electricity best when in a disordered amorphous phase. ©KTSDESIGN/Science Photo Library/Getty Courtesy: A*STAR

Iron-tellurium conducts electricity best when in a disordered amorphous phase. ©KTSDESIGN/Science Photo Library/Getty Courtesy: A*STAR

An Oct. 7, 2016 A*STAR press release, which originated the news item, explains more,

FeTe is a phase-change material, with the ability to rapidly switch its state from crystalline to amorphous and back again when it is heated or cooled, a property which makes it useful for data storage and memory applications. Conventional phase-change materials such as germanium-antimony-tellurium (GST), commonly used in rewritable DVDs, display higher optical reflectivity and electrical conductivity in their crystalline state because the highly-ordered structuring of atoms in the crystal results in more electron vacancies, or holes, that act as charge carriers.

“FeTe behaves differently from other phase-change materials,” explains Kewu Bai at the A*STAR Institute of High Performance Computing, who worked on the project with scientists from the National University of Singapore. “We hypothesized that these unusual characteristics may be connected with the behavior of ‘lone-pair’ electrons. This refers to a pair of electrons from any one atom that are not involved in the bonding of materials.”

The team prepared thin films of FeTe at room temperature to produce amorphous structures, and at 220 degrees Celsuis to acquire crystalline samples, and showed that the films could be flipped between the two states using a fast pulsing laser. They analyzed the molecular structure of the different films using X-ray spectroscopy, electron microscopy and first-principle calculations to investigate these unusual properties of FeTe.

The researchers confirmed the existence of lone-pair electrons in both the amorphous and crystalline phases. In the crystalline phase, where Te and Fe atoms were strongly bonded in a regular lattice, electrons were engaged in strong hybridization, meaning their orbitals overlapped and caused their electrons to localize. Thus, lone-pair electrons were incorporated as part of the integral structure.

In contrast, when FeTe entered its amorphous phase, some Te atoms were orientated so that their lone-pair electrons delocalized from the atoms, resulting in holes that acted as charge carriers.

“We are hopeful that FeTe could prove to be useful material for phase-change memory,” says Bai. “It could also act as an effective thermo-electric material, generating electric current in response to temperature.”

Here’s a link to and a citation for the paper,

Unravelling the anomalous electrical and optical phase-change characteristics in FeTe by H.W. Ho, P.S. Branicio, W.D. Song, K. Bai, Teck L. Tan, R. Ji, Y. Yang, P. Yang, Y.H. Du, M.B. Sullivan. Acta Materialia Volume 112, 15 June 2016, Pages 67–76  http://dx.doi.org/10.1016/j.actamat.2016.04.017

This paper is behind a paywall.

Oil spill cleanup nanotechnology-enabled solution from A*STAR

A*STAR (Singapore’s Agency for Science Technology and Research) has developed a new technology for cleaning up oil spills according to an Oct. 11, 2016 news item on Nanowerk,

Oceanic oil spills are tough to clean up. They dye feathers a syrupy sepia and tan fish eggs a toxic tint. The more turbulent the waters, the farther the slick spreads, with inky droplets descending into the briny deep.

Now technology may be able to succeed where hard-working volunteers have failed in the past. Researchers at the A*STAR Institute of Bioengineering and Nanotechnology (IBN) are using nanotechnology to turn an oil spill into a floating mass of brown jelly that can be scooped up before it can make its way into the food chain.

“Nanoscience makes it possible to tailor the essential structures of materials at the nanometer scale to achieve specific properties,” says chemist Yugen Zhang at IBN, who is developing some of the technologies. “Structures and materials in the nanometer size range often take on distinctive properties that are not seen in other size ranges,” adds Huaqiang Zeng, another chemist at IBN.

An Oct. 11, 2016 A*STAR press release, which originated the news item, describes some of problematic solutions before describing the new technology,

There are many approaches to cleaning an oil spill, and none are completely effective. Fresh, thick grease can be set ablaze or contained by floating barriers for skimmers to scoop out. The slick can also be inefficiently hardened, messily absorbed, hazardously dispersed, or slowly consumed by oil-grazing bacteria. All of these are deficient on a large scale, especially in rough waters.

Organic molecules with special gelling abilities offer a cheap, simple and environmentally friendly alternative for cleaning up the mess. Zeng has developed several such molecules that turn crude oil into jelly within minutes.

To create his ‘supergelators’, Zeng designed the molecules to associate with each other without forming physical bonds. When sprayed on contaminated seawater, the molecules immediately bundle into long fibers between 40 and 800 nanometers wide. These threads create a web that traps the interspersed oil in a giant blob that floats on the water’s surface. The gunk can then be swiftly sieved out of the ocean. Valuable crude oil can later be reclaimed using a common technique employed by petroleum refineries called fractional distillation.

Zeng tested the supergelators on four types of crude oil with different densities, viscosities and sulfur levels in a small round dish. The results were impressive. “The supergelators solidified both freshly spilled crude oil and highly weathered crude oil 37 to 60 times their own weight,” says Zeng. The materials used to produce these organic molecules are cheap and non toxic, which make them a commercially viable solution for managing accidents out at sea. Zeng hopes to work with industrial partners to test the nanomolecules on a much larger scale.

Zeng and his colleagues have developed other other ‘water’ applications as well,

Unsalty water

Scientists at IBN are also using nanoscience to remove salt from seawater and heavy metals from contaminated water.

With dwindling global fresh and ground water reserves, many countries are looking to desalination as a viable source of drinking water. Desalination is expected to meet 30 per cent of the water demand of Singapore by 2060, which will mean tripling the country’s current desalination capacity. But desalination demands huge energy consumption and reverse osmosis, the mainstream technology it depends on, has a relatively high cost. Reverse osmosis works by using extreme pressures to squeeze water molecules through tightly knit membranes.

An emerging alternative solution mimics the way proteins embedded in cell membranes, known as aquaporins, channel water in and out. Some research groups have even created membranes made of fatty lipid molecules that can accommodate natural aquaporins. Zeng has developed a cheaper and more resilient replacement.

His building blocks consist of helical noodles with sticky ends that connect to form long spirals. Water molecules can flow through the 0.3 nanometer openings at the center of the spirals, but all the other positively and negatively charged ions that make up saltwater are too bulky to pass. These include sodium, potassium, calcium, magnesium, chlorine and sulfur oxide. “In water, all of these ions are highly hydrated, attached to lots of water molecules, which makes them too large to go through the channels,” says Zeng.

The technology could lead to global savings of up to US$5 billion a year, says Zeng, but only after several more years of testing and tweaking the lipid membrane’s compatibility and stability with the nanospirals. “This is a major focus in my group right now,” he says. “We want to get this done, so that we can reduce the cost of water desalination to an acceptable level.”

Stick and non-stick

Nanomaterials also offer a low-cost, effective and sustainable way to filter out toxic metals from drinking water.

Heavy metal levels in drinking water are stringently regulated due to the severe damage the substances can cause to health, even at very low concentrations. The World Health Organization requires that levels of lead, for example, remain below ten parts per billion (ppb). Treating water to these standards is expensive and extremely difficult.

Zhang has developed an organic substance filled with pores that can trap and remove toxic metals from water to less than one ppb. Each pore is ten to twenty nanometers wide and packed with compounds, known as amines that stick to the metals.

Exploiting the fact that amines lose their grip over the metals in acidic conditions, the valuable and limited resource can be recovered by industry, and the polymers reused.

The secret behind the success of Zhang’s polymers is the large surface area covered by the pores, which translates into more opportunities to interact with and trap the metals. “Other materials have a surface area of about 100 square meters per gram, but ours is 1,000 square meters per gram,” says Zhang. “It is 10 times higher.”

Zhang tested his nanoporous polymers on water contaminated with lead. He sprinkled a powdered version of the polymer into a slightly alkaline liquid containing close to 100 ppb of lead. Within seconds, lead levels reduced to below 0.2 ppb. Similar results were observed for cadmium, copper and palladium. Washing the polymers in acid released up to 93 per cent of the lead.

With many companies keen to scale these technologies for real-world applications, it won’t be long before nanoscience treats the Earth for its many maladies.

I wonder if the researchers have found industrial partners (who could be named) to bring these solutions for oil spill cleanups, desalination, and water purification to the market.

Barnacle footprints could be useful

An Aug. 18, 2016 news item on Nanowerk describes efforts by scientists at the University of Twente (The Netherlands) and A*STAR (Singapore) to trace a barnacle’s footprints (Note: A link has been removed),

Barnacle’s larvae leave behind tiny protein traces on a ship hull: but what is the type of protein and what is the protein-surface interaction? Conventional techniques can only identify dissolved proteins, and in large quantities. Using a modified type of an Atomic Force Microscope, scientists of the University of Twente in The Netherlands and A*STAR in Singapore, can now measure protein characteristics of even very small traces on a surface. They present the new technique in Nature Nanotechnology (“Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample”).

An Aug. 16, 2016 University of Twente press release, which originated the news item, explains how the ‘footprints’ could lead to new applications for ships and boats and briefly describes the technical aspects of the research,

In infection diseases, membrane fouling, interaction with bacteria, as well as in rapid healing of wounds for example, the way proteins interact with a surface plays an important role. On a surface, they function in a different way than in solution. On a ship hull, the larvae of the barnacle will leave tiny traces of protein to test if the surface is attractive for long-term attachment. If we get to know more about this interaction, it will be possible to develop surface conditions that are less attractive for the barnacle. Large amounts of barnacles on a ship will have a destructive effect on flow resistance and will lead to more fuel consumption. The new measuring method makes use of a modified Atomic Force Microscope: a tiny ball glued to the cantilever of the microscope will attract protein molecules.

Modified AFM tip with a tiny ball that can attract protein molecules


An amount of just hundreds of protein molecules will be sufficient to determine a crucial value, called the iso-electric point (pI): this is the pH-value at which the protein has net zero electric charge. The pI value says a lot about the surroundings a protein will ‘feel comfortable’ in, and to which it preferably moves. Using the AFM microscope, of which the modified tip has collected protein molecules, it is possible to perform force measurements for different pH values. The tip will be attracted or repelled, or show no movement when the pI point is reached. For these measurement, the researchers made a special reference material consisting of several layers. Using this, the effect of a number of pH-values can be tested until the pI value is found.

The traces the larve leaves behind (left) and force measurements (right)


The tests have been successfully performed for a number of known proteins like fibrinogen, myoglobine and bovine albumin. And returning to the barnacle: the tiny protein footprint will contain enough molecules to determine the pI value. This quantifies the ideal surface conditions, and using this knowledge, new choices can be made for e.g. the paint that is used on a ship hull.

The research has been done within the group Materials Science and Technology of Polymers of Professor Julius Vancso, in close collaboration with colleagues of A*STAR in Singapore – Prof Vancso is a Visiting Professor there as well. His group is part of UT’s MESA+ Institute for Nanotechnology.

Here’s a link to and a citation for the paper,

Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample by Shifeng Gu, Xiaoying Zhu, Dominik Jańczewski, Serina Siew Chen Lee, Tao He, Serena Lay Ming Teo, & G. Julius Vancso.  Nature Nanotechnology (2016) doi:10.1038/nnano.2016.118 Published online 25 July 2016

This paper is behind a paywall.

Oil spill cleanups with supergelators

Researchers in Singapore have proposed a new technology for cleaning up oil spills, according to a June 17, 2016 news item on Nanowerk,

Large-scale oil spills, where hundreds of tons of petroleum products are accidentally released into the oceans, not only have devastating effects on the environment, but have significant socio-economic impact as well [1].

Current techniques of cleaning up oil spills are not very efficient and may even cause further pollution or damage to the environment. These methods, which include the use of toxic detergent-like compounds called dispersants or burning of the oil slick, result in incomplete removal of the oil. The oil molecules remain in the water over long periods and may even be spread over a larger area as they are carried by wind and waves. Further, burning can only be applied to fresh oil slicks of at least 3 millimeters thick, and this process would also cause secondary environmental pollution.

In a bid to improve the technology utilized by cleanup crews to manage and contain such large spills, researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR [located in Singapore] have invented a smart oil-scavenging material or supergelators that could help clean up oil spills efficiently and rapidly to prevent secondary pollution.

These supergelators are derived from highly soluble small organic molecules, which instantly self-assemble into nanofibers to form a 3D net that traps the oil molecules so that they can be removed easily from the surface of the water.

A June 17, 2016 IBN A*STAR media release, which originated the news item, provides more detail,

“Marine oil spills have a disastrous impact on the environment and marine life, and result in an enormous economic burden on society. Our rapid-acting supergelators offer an effective cleanup solution that can help to contain the severe environmental damage and impact of such incidents in the future,” said IBN Executive Director Professor Jackie Y. Ying.

Motivated by the urgent need for a more effective oil spill control solution, the IBN researchers developed new compounds that dissolve easily in environmentally friendly solvents and gel rapidly upon contact with oil. The supergelator molecules arrange themselves into a 3D network, entangling the oil molecules into clumps that can then be easily skimmed off the water’s surface.

“The most interesting and useful characteristic of our molecules is their ability to stack themselves on top of each other. These stacked columns allow our researchers to create and test different molecular constructions, while finding the best structure that will yield the desired properties,” said IBN Team Leader and Principal Research Scientist Dr Huaqiang Zeng. (Animation: Click to see how the supergelators stack themselves into columns.)

IBN’s supergelators have been tested on various types of weathered and unweathered crude oil in seawater, and have been found to be effective in solidifying all of them. The supergelators take only minutes to solidify the oil at room temperature for easy removal from water. In addition, tests carried out by the research team showed that the supergelator was not toxic to human cells, as well as zebrafish embryos and larvae. The researchers believe that these qualities would make the supergelators suitable for use in large oil spill areas.

The Institute is looking for industrial partners to further develop its technology for commercial use. [emphasis mine]

Video: Click to watch the supergelators in action

  1. The well documented BP Gulf of Mexico oil well accident in 2010 was a catastrophe on an unprecedented scale, with damages amounting to hundreds of billions of dollars. Its wide-ranging effects on the marine ecosystem, as well as the fishing and tourism industries, can still be felt six years on.

Here’s a link to and a citation for the paper,

Instant Room-Temperature Gelation of Crude Oil by Chiral Organogelators by Changliang Ren, Grace Hwee Boon Ng, Hong Wu, Kiat-Hwa Chan, Jie Shen, Cathleen Teh, Jackie Y. Ying, and Huaqiang Zeng. Chem. Mater., 2016, 28 (11), pp 4001–4008 DOI: 10.1021/acs.chemmater.6b01367 Publication Date (Web): May 10, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

I have featured other nanotechnology-enabled oil spill cleanup solutions here. One of the more recent pieces is my Dec. 7, 2015 post about boron nitride sponges. The search terms: ‘oil spill’ and ‘oil spill cleanup’ will help you unearth more.

There have been some promising possibilities and I hope one day these clean up technologies will be brought to market.

International NanoCar race: 1st ever to be held in Autumn 2016

They have a very intriguing set of rules for the 1st ever International NanoCar Race to be held in Toulouse, France in October 2016. From the Centre d’Élaboration de Matériaux et d’Études Structurales (CEMES) Molecule-car Race International page (Note: A link has been removed),

1) General regulations

The molecule-car of a registered team has at its disposal a runway prepared on a small portion of the (111) face of the same crystalline gold surface. The surface is maintained at a very low temperature that is 5 Kelvin = – 268°C (LT) in ultra-high vacuum that is 10-8 Pa or 10-10 mbar 10-10 Torr (UHV) for at least the duration of the competition. The race itself last no more than 2 days and 2 nights including the construction time needed to build up atom by atom the same identical runway for each competitor. The construction and the imaging of a given runway are obtained by a low temperature scanning tunneling microscope (LT-UHV-STM) and certified by independent Track Commissioners before the starting of the race itself.

On this gold surface and per competitor, one runway is constructed atom by atom using a few surface gold metal ad-atoms. A molecule-car has to circulate around those ad-atoms, from the starting to the arrival lines, each line being delimited by 2 gold ad-atoms. The spacing between two metal ad-atoms along a runway is less than 4 nm. A minimum of 5 gold ad-atoms line has to be constructed per team and per runway.

The organizers have included an example of a runway,

A preliminary runway constructed by C. Manzano and We Hyo Soe (A*Star, IMRE) in Singapore, with the 2 starting gold ad-atoms, the 5 gold ad-atoms for the track and the 2 gold ad-atoms had been already constructed atom by atom.

A preliminary runway constructed by C. Manzano and We Hyo Soe (A*Star, IMRE) in Singapore, with the 2 starting gold ad-atoms, the 5 gold ad-atoms for the track and the 2 gold ad-atoms had been already constructed atom by atom.

A November 25, 2015 [France] Centre National de la Recherche Scientifique (CNRS) press release notes that five teams presented prototypes at the Futurapolis 2015 event preparatory to the upcoming Autumn 2016 race,

The French southwestern town of Toulouse is preparing for the first-ever international race of molecule-cars: five teams will present their car prototype during the Futurapolis event on November 27, 2015. These cars, which only measure a few nanometers in length and are propelled by an electric current, are scheduled to compete on a gold atom surface next year. Participants will be able to synthesize and test their molecule-car until October 2016 prior to taking part in the NanoCar Race organized at the CNRS Centre d’élaboration des matériaux et d’études structurales (CEMES) by Christian Joachim, senior researcher at the CNRS and Gwénaël Rapenne, professor at Université Toulouse III-Paul Sabatier, with the support of the CNRS.

There is a video describing the upcoming 2016 race (English, spoken and in subtitles),

NanoCar Race, the first-ever race of molecule-cars by CNRS-en

A Dec. 14, 2015 Rice University news release provides more detail about the event and Rice’s participation,

Rice University will send an entry to the first international NanoCar Race, which will be held next October at Pico-Lab CEMES-CNRS in Toulouse, France.

Nobody will see this miniature grand prix, at least not directly. But cars from five teams, including a collaborative effort by the Rice lab of chemist James Tour and scientists at the University of Graz, Austria, will be viewable through sophisticated microscopes developed for the event.

Time trials will determine which nanocar is the fastest, though there may be head-to-head races with up to four cars on the track at once, according to organizers.

A nanocar is a single-molecule vehicle of 100 or so atoms that incorporates a chassis, axles and freely rotating wheels. Each of the entries will be propelled across a custom-built gold surface by an electric current supplied by the tip of a scanning electron microscope. The track will be cold at 5 kelvins (minus 450 degrees Fahrenheit) and in a vacuum.

Rice’s entry will be a new model and the latest in a line that began when Tour and his team built the world’s first nanocar more than 10 years ago.

“It’s challenging because, first of all, we have to design a car that can be manipulated on that specific surface,” Tour said. “Then we have to figure out the driving techniques that are appropriate for that car. But we’ll be ready.”

Victor Garcia, a graduate student at Rice, is building what Tour called his group’s Model 1, which will be driven by members of Professor Leonhard Grill’s group at Graz. The labs are collaborating to optimize the design.

The races are being organized by the Center for Materials Elaboration and Structural Studies (CEMES) of the French National Center for Scientific Research (CNRS).

The race was first proposed in a 2013 ACS Nano paper by Christian Joachim, a senior researcher at CNRS, and Gwénaël Rapenne, a professor at Paul Sabatier University.

Joining Rice are teams from Ohio University; Dresden University of Technology; the National Institute for Materials Science, Tsukuba, Japan; and Paul Sabatier [Université Toulouse III-Paul Sabatier].

I believe there’s still time to register an entry (from the Molecule-car Race International page; Note: Links have been removed),

To register for the first edition of the molecule-car Grand Prix in Toulouse, a team has to deliver to the organizers well before March 2016:

  • The detail of its institution (Academic, public, private)
  • The design of its molecule-vehicle including the delivery of the xyz file coordinates of the atomic structure of its molecule-car
  • The propulsion mode, preferably by tunneling inelastic effects
  • The evaporation conditions of the molecule-vehicles
  • If possible a first UHV-STM image of the molecule-vehicle
  • The name and nationality of the LT-UHV-STM driver

Those information are used by the organizers for selecting the teams and for organizing training sessions for the accepted teams in a way to optimize their molecule-car design and to learn the driving conditions on the LT-Nanoprobe instrument in Toulouse. Then, the organizers will deliver an official invitation letter for a given team to have the right to experiment on the Toulouse LT-Nanoprobe instrument with their own drivers. A detail training calendar will be determined starting September 2015.

The NanoCar Race website’s homepage notes that it will be possible to view the race in some fashion,

The NanoCar Race is a race where molecular machines compete on a nano-sized track. A NanoCar is a single molecule-car that has wheels and a chassis… and is propelled by a small electric shock.

The race will be invisible to the naked eye: a unique microscope based in Toulouse, France, will make it possible to watch the competition.

The NanoCar race is mostly a fantastic human and scientific adventure that will be broadcast worldwide. [emphasis mine]

Good luck to all the competitors.

Not the same old gold: there’s a brand new phase

A Dec. 7, 2015 news item on ScienceDaily announces a new phase for gold has been identified,

A new and stable phase of gold with different physical and optical properties from those of conventional gold has been synthesized by Agency for Science, Technology and Research (A*STAR) researchers [1], Singapore, and promises to be useful for a wide range of applications, including plasmonics and catalysis.

Many materials exist in a variety of crystal structures, known as phases or polymorphs. These different phases have the same chemical composition but different physical structures, which give rise to different properties. For example, two well-known polymorphs of carbon, graphite and diamond, arranged differently, have radically different physical properties, despite being the same element.

Gold has been used for many purposes throughout history, including jewelry, electronics and catalysis. Until now it has always been produced in one phase ― a face-centered cubic structure in which atoms are located at the corners and the center of each face of the constituent cubes.

Now, Lin Wu and colleagues at the Institute of the A*STAR Institute of High Performance Computing have modeled the optical and plasmonic properties of nanoscale ribbons of a new phase of gold — the 4H hexagonal phase (…) — produced and characterized by collaborators at other institutes in Singapore, China and the USA. The team synthesized nanoribbons of the new phase by simply heating the gold (III) chloride hydrate (HAuCl4) with a mixture of three organic solvents and then centrifuging and washing the product. This gave a high yield of about 60 per cent.

Here’s an image supplied by the researchers,

The atomic structure of the new phase of gold synthesized by A*STAR researchers. Reproduced from Ref. 1 and licensed under CC BY 4.0 © 2015 Z. Fan et al.

The atomic structure of the new phase of gold synthesized by A*STAR researchers. Reproduced from Ref. 1 and licensed under CC BY 4.0 © 2015 Z. Fan et al.

A Dec. 2, 2015 A*STAR news release, which originated the news item, provides more details,

The researchers also produced 4H hexagonal phases of the precious metals silver, platinum and palladium by growing them on top of the gold 4H hexagonal phase.

The cubic phase looks identical when viewed front on, from one side or from above. In contrast, the new 4H hexagonal phase lacks this cubic symmetry and hence varies more with direction — a property known as anisotropy. This lower symmetry gives it more directionally varying optical properties, which may make it useful for plasmonic applications. “Our finding is not only is of fundamental interest, but it also provides a new avenue for unconventional applications of plasmonic devices,” says Wu.

The team is keen to explore the potential of their new phase. “In the future, we hope to leverage the unconventional anisotropic properties of the new gold phase and design new devices with excellent performances not achievable with conventional face-centered-cubic gold,” says Wu. The synthesis method also gives rise to the potential for new strategies for controlling the crystalline phase of nanomaterials made from the noble metals.

Here’s a link to and a citation for the paper,

Stabilization of 4H hexagonal phase in gold nanoribbons by Zhanxi Fan, Michel Bosman, Xiao Huang, Ding Huang, Yi Yu, Khuong P. Ong, Yuriy A. Akimov, Lin Wu, Bing Li, Jumiati Wu, Ying Huang, Qing Liu, Ching Eng Png, Chee Lip Gan, Peidong Yang & Hua Zhang. Nature Communications 6, Article number: 7684 doi:10.1038/ncomms8684 Published 28 July 2015

This is an open access paper.

Single molecule nanogold-based probe for photoacoustic Imaging and SERS biosensing

As I understand it, the big deal is that A*STAR (Singapore’s Agency for Science, Rechnology and Research) scientists have found a way to make a single molecule probe do the work of a two-molecule probe when imaging tumours. From a July 29, 2015 news item on Nanowerk (Note: A link has been removed),

An organic dye that can light up cancer cells for two powerful imaging techniques providing complementary diagnostic information has been developed and successfully tested in mice by A*STAR researchers (“Single Molecule with Dual Function on Nanogold: Biofunctionalized Construct for In Vivo Photoacoustic Imaging and SERS Biosensing”).

A July 29, 2015 A*STAR news release, which originated the news item, describes the currently used multimodal imaging technique and provides details about the new single molecule technique,

Imaging tumors is vitally important for cancer research, but each imaging technique has its own limitations for studying cancer in living organisms. To overcome the limitations of individual techniques, researchers typically employ a combination of various imaging methods — a practice known as multimodal imaging. In this way, they can obtain complementary information and hence a more complete picture of cancer.

Two very effective methods for imaging tumors are photoacoustic imaging and surface-enhanced Raman scattering (SERS). Photoacoustic imaging can image deep tissue with a good resolution, whereas SERS detects miniscule amounts of a target molecule. To simultaneously use both photoacoustic imaging and SERS, a probe must produce signals for both imaging modalities.

In multimodal imaging, researchers typically combine probes for each imaging modality into a single two-molecule probe. However, the teams of Malini Olivo at the A*STAR Singapore Bioimaging Consortium and Bin Liu at the A*STAR Institute of Materials Research and Engineering, along with overseas collaborator Ben Zhong Tang from the Hong Kong University of Science and Technology, adopted a different approach — they developed single-molecule probes that can be used for both photoacoustic imaging and SERS. The probes are based on organic cyanine dyes that absorb near-infrared light, which has the advantage of being able to deeply penetrate tissue, enabling tumors deep within the body to be imaged.

Once the team had verified that the probes worked for both imaging modalities, they optimized the performances of the probes by adding gold nanoparticles to them to amplify the SERS signal and by encapsulating them in the polymer polyethylene glycol to stabilize their structures.

The researchers then deployed these optimized probes in live mice. By functionalizing the probes with an antibody that recognizes a tumor cell-surface protein, they were able to use them to target tumors. The scientists found that, in photoacoustic imaging, the tumor-targeted probes produced signals that were roughly three times stronger than those of unmodified probes. Using SERS, the team was also able to monitor the concentrations of the probes in the tumor, spleen and liver in real time with a high degree of sensitivity.

U. S. Dinish, a senior scientist in Olivo’s group, recalls the team’s “surprise at the sensitivity and potential of the nanoconstruct.” He anticipates that the probe could be used to guide surgical removal of tumors.

Here’s a link to and a citation for the paper,

Single Molecule with Dual Function on Nanogold: Biofunctionalized Construct for In Vivo Photoacoustic Imaging and SERS Biosensing by U. S. Dinish, Zhegang Song, Chris Jun Hui Ho, Ghayathri Balasundaram, Amalina Binte Ebrahim Attia, Xianmao Lu, Ben Zhong Tang, Bin Liu, and Malini Olivo. Advanced Functional Materials, Vol 25 Issue 15
pages 2316–2325, April 15, 2015 DOI: 10.1002/adfm.201404341 Article first published online: 11 MAR 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Brain-like computing with optical fibres

Researchers from Singapore and the United Kingdom are exploring an optical fibre approach to brain-like computing (aka neuromorphic computing) as opposed to approaches featuring a memristor or other devices such as a nanoionic device that I’ve written about previously. A March 10, 2015 news item on Nanowerk describes this new approach,

Computers that function like the human brain could soon become a reality thanks to new research using optical fibres made of speciality glass.

Researchers from the Optoelectronics Research Centre (ORC) at the University of Southampton, UK, and Centre for Disruptive Photonic Technologies (CDPT) at the Nanyang Technological University (NTU), Singapore, have demonstrated how neural networks and synapses in the brain can be reproduced, with optical pulses as information carriers, using special fibres made from glasses that are sensitive to light, known as chalcogenides.

“The project, funded under Singapore’s Agency for Science, Technology and Research (A*STAR) Advanced Optics in Engineering programme, was conducted within The Photonics Institute (TPI), a recently established dual institute between NTU and the ORC.”

A March 10, 2015 University of Southampton press release (also on EurekAlert), which originated the news item, describes the nature of the problem that the scientists are trying address (Note: A link has been removed),

Co-author Professor Dan Hewak from the ORC, says: “Since the dawn of the computer age, scientists have sought ways to mimic the behaviour of the human brain, replacing neurons and our nervous system with electronic switches and memory. Now instead of electrons, light and optical fibres also show promise in achieving a brain-like computer. The cognitive functionality of central neurons underlies the adaptable nature and information processing capability of our brains.”

In the last decade, neuromorphic computing research has advanced software and electronic hardware that mimic brain functions and signal protocols, aimed at improving the efficiency and adaptability of conventional computers.

However, compared to our biological systems, today’s computers are more than a million times less efficient. Simulating five seconds of brain activity takes 500 seconds and needs 1.4 MW of power, compared to the small number of calories burned by the human brain.

Using conventional fibre drawing techniques, microfibers can be produced from chalcogenide (glasses based on sulphur) that possess a variety of broadband photoinduced effects, which allow the fibres to be switched on and off. This optical switching or light switching light, can be exploited for a variety of next generation computing applications capable of processing vast amounts of data in a much more energy-efficient manner.

Co-author Dr Behrad Gholipour explains: “By going back to biological systems for inspiration and using mass-manufacturable photonic platforms, such as chalcogenide fibres, we can start to improve the speed and efficiency of conventional computing architectures, while introducing adaptability and learning into the next generation of devices.”

By exploiting the material properties of the chalcogenides fibres, the team led by Professor Cesare Soci at NTU have demonstrated a range of optical equivalents of brain functions. These include holding a neural resting state and simulating the changes in electrical activity in a nerve cell as it is stimulated. In the proposed optical version of this brain function, the changing properties of the glass act as the varying electrical activity in a nerve cell, and light provides the stimulus to change these properties. This enables switching of a light signal, which is the equivalent to a nerve cell firing.

The research paves the way for scalable brain-like computing systems that enable ‘photonic neurons’ with ultrafast signal transmission speeds, higher bandwidth and lower power consumption than their biological and electronic counterparts.

Professor Cesare Soci said: “This work implies that ‘cognitive’ photonic devices and networks can be effectively used to develop non-Boolean computing and decision-making paradigms that mimic brain functionalities and signal protocols, to overcome bandwidth and power bottlenecks of traditional data processing.”

Here’s a link to and a citation for the paper,

Amorphous Metal-Sulphide Microfibers Enable Photonic Synapses for Brain-Like Computing by Behrad Gholipour, Paul Bastock, Chris Craig, Khouler Khan, Dan Hewak. and Cesare Soci. Advanced Optical Materials DOI: 10.1002/adom.201400472
Article first published online: 15 JAN 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.

For anyone interested in memristors and nanoionic devices, here are a few posts (from this blog) to get you started:

Memristors, memcapacitors, and meminductors for faster computers (June 30, 2014)

This second one offers more details and links to previous pieces,

Memristor, memristor! What is happening? News from the University of Michigan and HP Laboratories (June 25, 2014)

This post is more of a survey including memristors, nanoionic devices, ‘brain jelly, and more,

Brain-on-a-chip 2014 survey/overview (April 7, 2014)

One comment, this brain-on-a-chip is not to be confused with ‘organs-on-a-chip’ projects which are attempting to simulate human organs (Including the brain) so chemicals and drugs can be tested.

Hydro-Québec, lithium-ion batteries, and silicate-based nanoboxes

Hydro-Québec (Canada) is making a bit of a splash these days (this is the third mention within less than a week) on my blog, if nowhere else. The latest development was announced in a Feb. 24, 2015 news item on Nanowerk (Note: A link has been removed),

Researchers from Singapore’s Institute of Bioengineering and Nanotechnology (IBN) of A*STAR and Quebec’s IREQ (Hydro-Québec’s research institute) have synthesized silicate-based nanoboxes that could more than double the energy capacity of lithium-ion batteries as compared to conventional phosphate-based cathodes (“Synthesis of Phase-Pure Li2MnSiO4@C Porous Nanoboxes for High-Capacity Li-Ion Battery Cathodes”). This breakthrough could hold the key to longer-lasting rechargeable batteries for electric vehicles and mobile devices.

A Feb. 24, 2015 Hydro-Québec press release (also on Canadian News Wire), which originated the news item, describe the research and the relationship between the two institutions,

“IBN researchers have successfully achieved simultaneous control of the phase purity and nanostructure of Li2MnSiO4 for the first time,” said Professor Jackie Y. Ying, IBN Executive Director. “This novel synthetic approach would allow us to move closer to attaining the ultrahigh theoretical capacity of silicate-based cathodes for battery applications.”

“We are delighted to collaborate with IBN on this project. IBN’s expertise in synthetic chemistry and nanotechnology allows us to explore new synthetic approaches and nanostructure design to achieve complex materials that pave the way for breakthroughs in battery technology, especially regarding transportation electrification,” said Dr. Karim Zaghib, Director – Energy Storage and Conservation at Hydro-Québec.

Lithium-ion batteries are widely used to power many electronic devices, including smart phones, medical devices and electric vehicles. Their high energy density, excellent durability and lightness make them a popular choice for energy storage. Due to a growing demand for long-lasting, rechargeable lithium-ion batteries for various applications, significant efforts have been devoted to improving the capacity of these batteries. In particular, there is great interest in developing new compounds that may increase energy storage capacity, stability and lifespan compared to conventional lithium phosphate batteries.

The five-year research collaboration between IBN and Hydro-Québec was established in 2011. The researchers plan to further enhance their new cathode materials to create high-capacity lithium-ion batteries for commercialization.

Here’s a link to and a citation for the paper,

Synthesis of phase-pure Li2MnSiO4@C porous nanoboxes for high-capacity Li-ion battery cathodes by Xian-Feng Yang, Jin-Hua Yang, Karim Zaghib, Michel L. Trudeau, and Jackie Y. Ying. Nano Energy Volume 12, March 2015, Pages 305–313 doi:10.1016/j.nanoen.2014.12.021

This paper is behind a paywall.

Here are my two most recent mentions of Hydro-Québec and lithium-ion batteries (both Grafoid and NanoXplore have deals with Hydro-Québec),

Investment in graphene (Grafoid), the Canadian government, and a 2015 federal election (Feb. 23, 2015)

NanoXplore: graphene and graphite in Québec (Canada) (Feb. 20, 2015)