Monthly Archives: November 2015

New tool for mapping neuronal connections in the brain

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This work comes from the US Naval Research Laboratory according to a Nov. 17, 2015 news item on Nanowerk (Note: A link has been removed),

Research biologists, chemists and theoreticians at the U.S. Naval Research Laboratory (NRL), are on pace to develop the next generation of functional materials that could enable the mapping of the complex neural connections in the brain (“Electric Field Modulation of Semiconductor Quantum Dot Photoluminescence: Insights Into the Design of Robust Voltage-Sensitive Cellular Imaging Probes”). The ultimate goal is to better understand how the billions of neurons in the brain communicate with one another during normal brain function, or dysfunction, as result of injury or disease.

“There is tremendous interest in mapping all the neuron connections in the human brain,” said Dr. James Delehanty, research biologist, Center for Biomolecular Science and Engineering. “To do that we need new tools or materials that allow us to see how large groups of neurons communicate with one another while, at the same time, being able to focus in on a single neuron’s activity. Our most recent work potentially opens the integration of voltage-sensitive nanomaterials into live cells and tissues in a variety of configurations to achieve real-time imaging capabilities not currently possible.”

A Nov. 17, 2015 US Naval Research Laboratory (NRL) news release on EurekAlert, which originated the news item, provides more details,

The basis of neuron communication is the time-dependent modulation of the strength of the electric field that is maintained across the cell’s plasma membrane. This is called an action potential. Among the nanomaterials under consideration for application in neuronal action potential imaging are quantum dots (QDs) — crystalline semiconductor nanomaterials possessing a number of advantageous photophysical attributes.

“QDs are very bright and photostable so you can look at them for long times and they allow for tissue imaging configurations that are not compatible with current materials, for example, organic dyes,” Delehanty added. “Equally important, we’ve shown here that QD brightness tracks, with very high fidelity, the time-resolved electric field strength changes that occur when a neuron undergoes an action potential. Their nanoscale size make them ideal nanoscale voltage sensing materials for interfacing with neurons and other electrically active cells for voltage sensing.”

QDs are small, bright, photo-stable materials that possess nanosecond fluorescence lifetimes. They can be localized within or on cellular plasma membranes and have low cytotoxicity when interfaced with experimental brain systems. Additionally, QDs possess two-photon action cross-section orders of magnitude larger than organic dyes or fluorescent proteins. Two-photon imaging is the preferred imaging modality for imaging deep (millimeters) into the brain and other tissues of the body.

In their most recent work, the NRL researchers showed that an electric field typical of those found in neuronal membranes results in suppression of the QD photoluminescence (PL) and, for the first time, that QD PL is able to track the action potential profile of a firing neuron with millisecond time resolution. This effect is shown to be connected with electric-field-driven QD ionization and consequent QD PL quenching, in contradiction with conventional wisdom that suppression of the QD PL is attributable to the quantum confined Stark effect — the shifting and splitting of spectral lines of atoms and molecules due to presence of an external electric field.

“The inherent superior photostability properties of QDs coupled with their voltage sensitivity could prove advantageous to long-term imaging capabilities that are not currently attainable using traditional organic voltage sensitive dyes,” Delehanty said. “We anticipate that continued research will facilitate the rational design and synthesis of voltage-sensitive QD probes that can be integrated in a variety of imaging configurations for the robust functional imaging and sensing of electrically active cells.”

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

Electric Field Modulation of Semiconductor Quantum Dot Photoluminescence: Insights Into the Design of Robust Voltage-Sensitive Cellular Imaging Probes by Clare E. Rowland, Kimihiro Susumu, Michael H. Stewart, Eunkeu Oh, Antti J. Mäkinen, Thomas J. O’Shaughnessy, Gary Kushto, Mason A. Wolak, Jeffrey S. Erickson, Alexander L. Efros, Alan L. Huston, and James B. Delehanty. Nano Lett., 2015, 15 (10), pp 6848–6854 DOI: 10.1021/acs.nanolett.5b02725 Publication Date (Web): September 28, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

Lockheed Martin upgrades to 1000+ Qubit D-Wave system

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D-Wave Systems, a Canadian quantum computing company, seems to be making new business announcements on a weekly basis. After last week’s US Los Alamos National Laboratory announcement (Nov. 12, 2015 posting) , there’s a Nov. 16, 2015 news item on Nanotechnology Now,

Harris & Harris Group, Inc. (NASDAQ:TINY), an investor in transformative companies enabled by disruptive science, notes that its portfolio company, D-Wave Systems, Inc., announced that it has entered into a multi-year agreement with Lockheed Martin to upgrade the company’s 512-qubit D-Wave Two™ quantum computer to the new D-Wave 2X™ system with 1,000+ qubits.

A Nov. 16, 2015 D-Wave Systems news release provides more details about the deal,

D-Wave Systems Inc., the world’s first quantum computing company, today announced that it has entered into a multi-year agreement with Lockheed Martin (NYSE: LMT) to upgrade the company’s 512-qubit D-Wave Two™ quantum computer to the new D-Wave 2X™ system with 1,000+ qubits. This represents the second system upgrade since Lockheed Martin became D-Wave’s first customer in 2011 with the purchase of a 128 qubit D-Wave One™ system. The agreement includes the system, maintenance and associated professional services.

“Our mission is to solve complex challenges, advance scientific discovery and deliver innovative solutions to our customers, which requires expertise in the most advanced technologies,” said Greg Tallant, Lockheed Martin fellow and lead for the University of Southern California-Lockheed Martin Quantum Computation Center (QCC). “Through our continued investment in D-Wave technology, we are able to push the boundaries of quantum computing and apply the latest technologies to address the real-world problems being faced by our customers.”

For quantum computing, the performance gain over traditional computing is most evident in exceedingly complex computational problems. This could be in areas such as validating the performance of software or vehicle planning and scheduling. With the new D-Wave system, Lockheed Martin researchers will be able to explore solutions for significantly larger computational problems with improved accuracy and execution time.

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The new system will be hosted at the University of Southern California-Lockheed Martin Quantum Computation Center, which first began exploring the power of quantum computing with the D-Wave One, the world’s first quantum computer.

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The installation of the D-Wave 2X system will be completed in January 2016.

Who knows what next week will bring for D-Wave, which by the way is located in Vancouver, Canada or, more accurately, Burnaby?

A 244-atom submarine powered by light

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James Tour lab researchers at Rice University announce in a Nov. 16, 2015 news item on Nanowerk,

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 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.

While they can’t be steered yet, the study proves molecular motors are powerful enough to drive the sub-10-nanometer subs through solutions of moving molecules of about the same size.

“This is akin to a person walking across a basketball court with 1,000 people throwing basketballs at him,” Tour said.

A Nov. 16, 2015 Rice University news release (also on EurekAlert), which originated the news item, provides context and details about the research,

Tour’s group has extensive experience with molecular machines. A decade ago, his lab introduced the world to nanocars, single-molecule cars with four wheels, axles and independent suspensions that could be “driven” across a surface.

Tour said many scientists have created microscopic machines with motors over the years, but most have either used or generated toxic chemicals. He said a motor that was conceived in the last decade by a group in the Netherlands proved suitable for Rice’s submersibles, which were produced in a 20-step chemical synthesis.

“These motors are well-known and used for different things,” said lead author and Rice graduate student Victor García-López. “But we were the first ones to propose they can be used to propel nanocars and now submersibles.”

The motors, which operate more like a bacteria’s flagellum than a propeller, complete each revolution in four steps. When excited by light, the double bond that holds the rotor to the body becomes a single bond, allowing it to rotate a quarter step. As the motor seeks to return to a lower energy state, it jumps adjacent atoms for another quarter turn. The process repeats as long as the light is on.

For comparison tests, the lab also made submersibles with no motors, slow motors and motors that paddle back and forth. All versions of the submersibles have pontoons that fluoresce red when excited by a laser, according to the researchers. (Yellow, sadly, was not an option.)

“One of the challenges was arming the motors with the appropriate fluorophores for tracking without altering the fast rotation,” García-López said.

Once built, the team turned to Gufeng Wang at North Carolina State University to measure how well the nanosubs moved.

“We had used scanning tunneling microscopy and fluorescence microscopy to watch our cars drive, but that wouldn’t work for the submersibles,” Tour said. “They would drift out of focus pretty quickly.”

The North Carolina team sandwiched a drop of diluted acetonitrile liquid containing a few nanosubs between two slides and used a custom confocal fluorescence microscope to hit it from opposite sides with both ultraviolet light (for the motor) and a red laser (for the pontoons).

The microscope’s laser defined a column of light in the solution within which tracking occurred, García-López said. “That way, the NC State team could guarantee it was analyzing only one molecule at a time,” he said.

Rice’s researchers hope future nanosubs will be able to carry cargoes for medical and other purposes. “There’s a path forward,” García-López said. “This is the first step, and we’ve proven the concept. Now we need to explore opportunities and potential applications.”

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

Unimolecular Submersible Nanomachines. Synthesis, Actuation, and Monitoring by Víctor García-López, Pinn-Tsong Chiang, Fang Chen, Gedeng Ruan, Angel A. Martí, Anatoly B. Kolomeisky, Gufeng Wang, and James M. Tour. Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.5b03764 Publication Date (Web): November 5, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

There is an illustration of the 244-atom submersible,

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

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

Primordial goo for implants

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Using the words ‘goo’ and ‘nanotechnology’ together almost always leads to ‘end of world’ scenarios referred to as  ‘grey goo‘ or there’s an alternative ‘green goo’ version also known as ecophagy. Presumably, that’s why Australian researchers avoided the word ‘nanotechnology’ in their study of the original goo, primordial goo from which all life oozed, to develop a coating for medical implants. From a Nov. 16, 2015 (Australia) Commonwealth Scientific and Industrial Research Organisation (CSIRO) press release (also on EurekAlert),

Australia’s national science research organisation, CSIRO, has developed an innovative new coating that could be used to improve medical devices and implants, thanks to a “goo” thought to be have been home to the building blocks of life.

The molecules from this primordial goo – known as prebiotic compounds – can be traced back billions of years and have been studied intensively since their discovery several decades ago.

For the first time, Australian researchers have uncovered a way to use these molecules to assist with medical treatments.

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“We wanted to use these prehistoric molecules, which are believed to have been the source of all life evolving on Earth, to see if we could apply the chemistry in a practical way.” [Dr. Richard Evans, CSIRO researcher]

The team discovered that the coating is bio-friendly and cells readily grow and colonise it.

It could be applied to medical devices to improve their performance and acceptance by the body.

This could assist with a range of medical procedures.

“The non-toxic coating (left) is adhesive and will coat almost any material making its potential biomedical applications really broad,” Dr Evans said.

The researchers also experimented with adding silver compounds, in order to produce an antibacterial coating that can be used on devices such as catheters to avoid infections.

“Other compounds can also be added to implants to reduce friction, make them more durable and resistant to wear,” Dr Evans said.

The coating process the scientists developed is very simple and uses methods and substances that are readily available.

This means biomedical manufacturers can produce improved results more cost effectively compared to existing coatings.

CSIRO is the first organisation to investigate practical applications of this kind using prebiotic chemistry.

“This research opens the door to a host of new biomedical possibilities that are still yet to be explored,” Dr Evans said.

CSIRO is seeking to partner with biomedical manufacturers to exploit this technology.

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

Prebiotic-chemistry inspired polymer coatings for biomedical and material science applications by Helmut Thissen, Aylin Koegler, Mario Salwiczek, Christopher D Easton, Yue Qu, Trevor Lithgow, and Richard A Evans.  NPG Asia Materials (2015) 7, e225; doi:10.1038/am.2015.122 Published online 13 November 2015

This is an open access paper,

STEM for refugees and disaster relief

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Just hours prior to the terrorist bombings in Paris (Friday, Nov. 13, 2015), Tash Reith-Banks published a Nov. 13, 2015 essay (one of a series) in the Guardian about science, technology, engineering, and mathematics (STEM) as those specialties apply to humanitarian aid with a special emphasis on Syrian refugee crisis.

This first essay focuses on how engineering and mathematics are essential when dealing with crises (from Reith-Banks’s Nov. 13, 2015 essay), Note: Links have been removed,

Engineering is a clear starting point: sanitation, shelter and supply lines are all essential in any crisis. As Martin McCann, CEO at RedR, which trains humanitarian NGO workers says: “There is the obvious work in providing water and sanitation and shelter. By shelter, we mean not only shelter or housing for disaster-affected people or refugees, but also structures to store both food and non-food items. Access is always critical, so once again engineers are needed to build roads or in some cases temporary landing strips.”

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Emergency structures need to be light and fast to transport and erect, but tend not to be durable. One recent development comes from engineers Peter Brewin and Will Crawford of Concrete Canvas., The pair have developed a rapid-setting concrete-impregnated fabric that requires only air and water to harden into a water-proof, fire-resistant construction. This has been used to create rapidly deployable concrete shelters that can be carried in a bag and set up in an hour.

Here’s what one of the concrete shelters looks like,

A Concrete Canvas shelter. Once erected the structure takes 24 hours to harden, and then can be further insulated with earth or snow if necessary. Photograph: Gareth Phillips/Gareth Phillips for the Guardian

A Concrete Canvas shelter. Once erected the structure takes 24 hours to harden, and then can be further insulated with earth or snow if necessary. Photograph: Gareth Phillips/Gareth Phillips for the Guardian

There are many kinds of crises which can lead to a loss of shelter, access to water and food, and diminished safety and health as Reith-Banks also notes in a passage featuring mathematics (Note: A link has been removed),

Maths might seem a far cry from the sort of practical innovation described above, but of course it’s the root of great logistics. Alistair Clark from the University of the West of England is using advanced mathematical modelling to improve humanitarian supply chains to ensure aid is sent exactly where it is needed. Part of the Newton Mobility scheme, Clark’s project will partner with Brazilian disaster relief agencies and develop ways of modelling everything from landslides to torrential downpours in order to create sophisticated humanitarian supply chains that can rapidly adapt to a range of possible disaster scenarios and changing circumstances.

In a similar vein, Professor Amr Elnashai, founder and co-editor of the Journal of Earthquake Engineering, works in earthquake-hit areas to plan humanitarian relief for future earthquakes. He recently headed a large research and development effort funded by the Federal Emergency Management Agency in the USA (FEMA), to develop a computer model of the impact of earthquakes on the central eight states in the USA. This included social impact, temporary housing allocation, disaster relief, medical and educational care, as well as engineering damage and its economic impact.

Reith-Banks also references nanotechnology (Note: A link has been removed),

… Up to 115 people die every hour in Africa from diseases linked to contaminated drinking water and poor sanitation, particularly in the wake of conflicts and environmental disasters. Dr Askwar Hilonga recently won the Royal Academy of Engineering Africa Prize, which is dedicated to African inventions with the potential to bring major social and economic benefits to the continent. Hilonga has invented a low cost, sand-based water filter. The filter combines nanotechnology with traditional sand-filtering methods to provide safe drinking water without expensive treatment facilities.  …

Dr. Hilonga who is based in Tanzania was featured here in a June 16, 2015 posting about the Royal Academy of Engineering Prize, his research, and his entrepreneurial efforts.

Reith-Banks’s* essay provides a valuable and unexpected perspective on the humanitarian crises which afflict this planet *and I’m looking forward to the rest of the series*.

*’Reith-Banks’s’ replaced ‘This’ and ‘and I’m looking forward to the rest of the series’ was added Nov. 17, 2015 at 1620 hours PST.

Setting a tone for Canadian science, now what about science and a culture of innovation?

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On the heels of reinstating the mandatory long form census, removing the muzzle from Canadian government scientists, and assigning multiple new ministers to old and new ‘science’ ministries, Justin Trudeau has delivered his new ministerial mandate letters where he thanks the ministers for agreeing to serve and lays out his priorities. David Bruggeman provides priority lists from two of the letters in a Nov. 13, 2015 posting on his Pasco Phronesis blog (Note: Links have been removed),

The new Science Minister, Kirsty Duncan, was given the following priorities in her letter:

Create a Chief Science Officer mandated to ensure that government science is fully available to the public, that scientists are able to speak freely about their work, and that scientific analyses are considered when the government makes decisions.
Support your colleagues in the review and reform of Canada’s environmental assessment processes to ensure that environmental assessment decisions are based on science, facts, and evidence.
Support the Minister of Employment, Workforce Development and Labour [emphasis mine] in efforts to help employers create more co-op placements for students in science, technology, engineering, mathematics, and business programs [emphasis mine].
Support your Ministerial colleagues as they re-insert scientific considerations into the heart of our decision-making and investment choices.

…

It’s worth noting – because it often gets lost – that this philosophy sees scientific knowledge and scientific considerations are but one input into policy and decision making.  [emphasis mine] Inform, not dictate.

It’s also worth noting that the Minister of Innovation, Science and Economic Development (MP Navdeep Bains) is mentioned just once in the Minister of Science letter.  Looking at the letter sent to Minister Bains, it would seem that PM Trudeau sees science in this portfolio in service to economic development and innovation.  The role as outlined in the letter:

“As Minister of Innovation, Science and Economic Development, your overarching goal will be to help Canadian businesses grow, innovate and export so that they can create good quality jobs and wealth for Canadians.  You will achieve this goal by working with provinces, territories, municipalities, the post-secondary education system, [emphasis mine] employers and labour to improve the quality and impact of our programs that support innovation, scientific research and entrepreneurship.  You will collaborate with provinces, territories and municipalities to align, where possible, your efforts.  I expect you to partner closely with businesses and sectors to support their efforts to increase productivity and innovation. …

I have a few comments about the ‘science’ letters. I’m happy to see the first priority for the Science minister is the appointment of a Chief Science Officer. David’s point about the letter’s emphasis that science is one input into the policy making process is interesting. Personally, I applaud the apparent even-handedness since scientific evidence is not always unequivocal but this does give the government some room to ignore scientific evidence in favour of other political considerations.

Finally, I see a gray area between the two ministries has been delineated with the Science minister being exhorted to:

“Support the Minister of Employment, Workforce Development and Labour in efforts to help employers create more co-op placements for students in science, technology, engineering, mathematics, and business programs”

and the Minister of Innovation, Science and Economic Development being exhorted to

” … achieve this goal [economic prosperity] by working with provinces, territories, municipalities, the post-secondary education system, employers and labour to improve the quality and impact of our programs that support innovation, scientific research and entrepreneurship.”

Note the crossover where the Science minister is being asked to help develop more coop placements while the Innovation, Science and Economic Development Minister is being asked to work with the post-secondary education system and employers to improve programs for entrepreneurship. Interestingly the exhortation for the Innovation minister is included in the general text of the letter and not in the list of priorities.

There is one other ministry I’d like to include here and it’s Canadian Heritage. While it might seem an odd choice to some, there is what seems to be an increasing interest in the relationship between art, science, and the humanities. While I’m thrilled with much of the content in the Heritage letter,  mentions of science and technology are notably absent. Given what’s happened in our cultural sector (serious funding cutbacks over several years from both the Conservative government and previous Liberal governments), it’s understandable and it’s good to see more funding (from the Canadian Heritage Ministerial Mandate letter),

As Minister of Canadian Heritage, your overarching goal will be to implement our government’s plan to strengthen our cultural and creative industries. Our cultural sector is an enormous source of strength to the Canadian economy. Canada’s stories, shaped by our immense diversity, deserve to be celebrated and shared with the world. Our plan will protect our important national institutions, safeguard our official languages, promote the industries that reflect our unique identity as Canadians, and provide jobs and economic opportunities in our cultural and creative sectors.

You will be the leader of a strong team of ministers, supported by the Minister of Sport and Persons with Disabilities and the Minister of Status of Women.

In particular, I will expect you to work with your colleagues and through established legislative, regulatory, and Cabinet processes to deliver on your top priorities:

  • Review current plans for Canada 150 [Canada will be celebrating its 150th anniversary in 2017] and champion government-wide efforts to promote this important celebration.
  • Restore and increase funding for CBC/Radio-Canada, following consultation with the broadcaster and the Canadian cultural community.
  • Review the process by which members are appointed to the CBC/Radio-Canada Board of Directors, to ensure merit-based and independent appointments.
  • Double investment in the Canada Council for the Arts.
  • Increase funding for Telefilm Canada and the National Film Board.
  • Restore the Promart and Trade Routes International cultural promotion programs, update their design, and increase related funding.
  • Increase funding for the Young Canada Works program to help prepare the next generation of Canadians working in the heritage sector.
  • Work with the Minister of Infrastructure and Communities to make significant new investments in cultural infrastructure as part of our investment in social infrastructure.
  • …
  • Work in collaboration with the Minister of Indigenous and Northern Affairs to provide new funding to promote, preserve and enhance Indigenous languages and cultures.
  • …

I hope at some point this government integrates a little science and technology into Canadian Heritage because we have often achieved breakthroughs, scientifically and technically, and we have, at times, achieved the impossible as anyone who’s taken a train ride through the Rocky Mountains knows. Plus, if the government wants to encourage entrepreneurship and risk-taking, Canadian artists of all types provide an excellent model.

For the interested, the Ministerial Mandate letters have been made publicly available.

Two final items, there’s a Nov. 16, 2015 posting by Josh Silberg on Science Borealis which provides a more comprehensive roundup of science commentary in the wake of the new Liberal government’s ascendance.  Yes, I’m on it and you may recognize some others as well but there should be one or two new writers to discover.

Second, Phil Plait who has written about Canadian science and the Conservative government’s policies many times provides a brief history of the situation along with a few ebullient comments about the changes that have been taking place. You can find it all in Plait’s Nov. 17, 2015 posting on Slate.com.

2015 daguerreotype exhibit follows problematic 2005 show

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In 2005, curators had a horrifying experience when historical images (daguerreotypes) were deteriorating as the 150-year old images were being displayed in an exhibit titled “Young America.” Some 25 of the photographs were affected, five of them sustaining critical damage. The debacle occasioned a research project involving conservators, physicists, and nanotechnology (see my Jan. 10, 2013 posting for more about the 2005 exhibit and resulting research project).

A new daguerreotype exhibit currently taking place showcases the results of that research according to a Nov. 13, 2015 University of Rochester news release,

In 1839, Louis-Jacques-Mandé Daguerre unveiled one of the world’s first successful photographic mediums: the daguerreotype. The process transformed the human experience by providing a means to capture light and record people, places, and events. The University of Rochester is leading groundbreaking nanotechnology research that explores the extraordinary qualities of this photographic process. A new exhibition in Rush Rhees Library showcases the results of this research, while bridging the gap between the sciences and the humanities. …

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… From 2010-2014, a National Science Foundation grant supported nanotechnology research conducted by two University of Rochester scientists—Nicholas Bigelow, Lee A. DuBridge Professor of Physics, and Ralph Wiegandt, visiting research scientist and conservator—who explored how environment impacts the survival of these unique, non-reproducible images. In addition to conservation science and cultural research, Bigelow and Wiegandt are also investigating ways in which the chemical and physical processes used to create daguerreotypes can influence modern nanofabrication and nanotechnology.

“The daguerreotype should be considered one of humankind’s most disruptive technological advances,” Bigelow and Wiegandt said. “Not only was it the first successful imaging medium, it was also the first truly engineered nanotechnology. The daguerreotype was a prescient catalyst to the ensuing cascade of discoveries in physics and chemistry over the latter half of the 19th century and into the 20th.”

Blending the past with the future, the exhibition displays the first known daguerreotype of a Rochester graduating class (1853) alongside a 2015 daguerreotype of current University President Joel Seligman, created by Rochester daguerreotypist Irving Pobboravsky.

Both Bigelow and Wiegandt are mentioned in the 2013 posting describing the research project’s inception.

For anyone who’s in the area of New York state where the University of Rochester is located, the exhibit will run until February 29, 2016 in the Friedlander Lobby of Rush Rhees Library.  Plus, there’s this from the news release,

A special presentation about the scientific advances surrounding the daguerreotype and their relationship to cultural preservation will be led by Bigelow, Wiegandt, and Jim Kuhn, assistant dean for Special Collections and Preservation, on December 14 from 7-9 p.m. in the Hawkins-Carlson Room of Rush Rhees Library. For more information visit: http://www.library.rochester.edu/event/daguerreotype-exhibition or call (585).

There’s no indication that the special presentation will be livestreamed or recorded and made available at a later date.

An app for nanomaterial risks (NanoRisk)

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It seems past time for someone to have developed an app for nanomaterial risks. A Nov. 12, 2015 news item on Nanowerk makes the announcement (Note: A link has been removed),

The NanoRisk App is a guide to help the researcher in the risk assessment of nanomaterials. This evaluation is determined based on the physicochemical characteristics and the activities to be carried out by staff in research laboratories.

The NanoRisk App was developed at the University of Los Andes or Universidad de los Andes in Colombia (there also seems to be one in Chile). From the Nano Risk App homepage,

The NanoRisk App application was developed at the University of Los Andes by the Department of Chemical Engineering and the Department of Electrical and Electronic Engineering, Faculty of Engineering and implemented in cooperation with the Department of Occupational Health at the University of Los Andes. This application focuses on the use of manufactured nanomaterials.

Authors

Homero Fernando Pastrana Rendón MD, MsC, PhD Candidate. Alba Graciela Ávila, Associate Professor, Department of Electrical and Electronic Engineering. Felipe Muñoz Giraldo, Professor Associate Professor, Department of Chemical Engineering, University of Los Andes.

Acknowledgements to Diego Angulo and Diana Fernandez, from the Imagine group, for all the support in the development of this application.

About the App

The app is a guide to help the researcher in the risk assessment of nanomaterials. This evaluation is determined based on the physicochemical characteristics and the activities to be carried out by staff in research laboratories. This is based on nano risk management strategies from various institutions such as the National Institute for Occupational Safety and Health, U.S. (NIOSH), the New Development Organization of Japan Energy and Industrial Technology (NEDO), the European Commission (Nanosafe Program) and the work developed by the Lawrence Livermore National Laboratory (California, USA) in conjunction with the Safety Science Group at the University of Delft in the Netherlands.

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RESULT:

The app will estimates the risk at four levels (low, medium, high and very high) for the hazard of the nanomaterial and the probability to be exposed to the material. Then it will recommend measures to contain the risk by applying engineering measures (controlled ventilation system, biosafety cabinet and glovebox).

They have a copyright notice on the page, as well as, instructions on how to access the App and the information.

Nanopores and a new technique for desalination

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There’s been more than one piece here about water desalination and purification and/or remediation efforts and at least one of them claims to have successfully overcome issues such as reverse osmosis energy needs which are hampering adoption of various technologies. Now, researchers at the University of Illinois at Champaign Urbana have developed another new technique for desalinating water while reverse osmosis issues according to a Nov. 11, 2015 news item on Nanowerk (Note: A link has been removed) ,

University of Illinois engineers have found an energy-efficient material for removing salt from seawater that could provide a rebuttal to poet Samuel Taylor Coleridge’s lament, “Water, water, every where, nor any drop to drink.”

The material, a nanometer-thick sheet of molybdenum disulfide (MoS2) riddled with tiny holes called nanopores, is specially designed to let high volumes of water through but keep salt and other contaminates out, a process called desalination. In a study published in the journal Nature Communications (“Water desalination with a single-layer MoS2 nanopore”), the Illinois team modeled various thin-film membranes and found that MoS2 showed the greatest efficiency, filtering through up to 70 percent more water than graphene membranes. [emphasis mine]

I’ll get to the professor’s comments about graphene membranes in a minute. Meanwhile, a Nov. 11, 2015 University of Illinois news release (also on EurekAlert), which originated the news item, provides more information about the research,

“Even though we have a lot of water on this planet, there is very little that is drinkable,” said study leader Narayana Aluru, a U. of I. professor of mechanical science and engineering. “If we could find a low-cost, efficient way to purify sea water, we would be making good strides in solving the water crisis.

“Finding materials for efficient desalination has been a big issue, and I think this work lays the foundation for next-generation materials. These materials are efficient in terms of energy usage and fouling, which are issues that have plagued desalination technology for a long time,” said Aluru, who also is affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I.

Most available desalination technologies rely on a process called reverse osmosis to push seawater through a thin plastic membrane to make fresh water. The membrane has holes in it small enough to not let salt or dirt through, but large enough to let water through. They are very good at filtering out salt, but yield only a trickle of fresh water. Although thin to the eye, these membranes are still relatively thick for filtering on the molecular level, so a lot of pressure has to be applied to push the water through.

“Reverse osmosis is a very expensive process,” Aluru said. “It’s very energy intensive. A lot of power is required to do this process, and it’s not very efficient. In addition, the membranes fail because of clogging. So we’d like to make it cheaper and make the membranes more efficient so they don’t fail as often. We also don’t want to have to use a lot of pressure to get a high flow rate of water.”

One way to dramatically increase the water flow is to make the membrane thinner, since the required force is proportional to the membrane thickness. Researchers have been looking at nanometer-thin membranes such as graphene. However, graphene presents its own challenges in the way it interacts with water.

Aluru’s group has previously studied MoS2 nanopores as a platform for DNA sequencing and decided to explore its properties for water desalination. Using the Blue Waters supercomputer at the National Center for Supercomputing Applications at the U. of I., they found that a single-layer sheet of MoS2 outperformed its competitors thanks to a combination of thinness, pore geometry and chemical properties.

A MoS2 molecule has one molybdenum atom sandwiched between two sulfur atoms. A sheet of MoS2, then, has sulfur coating either side with the molybdenum in the center. The researchers found that creating a pore in the sheet that left an exposed ring of molybdenum around the center of the pore created a nozzle-like shape that drew water through the pore.

“MoS2 has inherent advantages in that the molybdenum in the center attracts water, then the sulfur on the other side pushes it away, so we have much higher rate of water going through the pore,” said graduate student Mohammad Heiranian, the first author of the study. “It’s inherent in the chemistry of MoS2 and the geometry of the pore, so we don’t have to functionalize the pore, which is a very complex process with graphene.”

In addition to the chemical properties, the single-layer sheets of MoS2 have the advantages of thinness, requiring much less energy, which in turn dramatically reduces operating costs. MoS2 also is a robust material, so even such a thin sheet is able to withstand the necessary pressures and water volumes.

The Illinois researchers are establishing collaborations to experimentally test MoS2 for water desalination and to test its rate of fouling, or clogging of the pores, a major problem for plastic membranes. MoS2 is a relatively new material, but the researchers believe that manufacturing techniques will improve as its high performance becomes more sought-after for various applications.

“Nanotechnology could play a great role in reducing the cost of desalination plants and making them energy efficient,” said Amir Barati Farimani, who worked on the study as a graduate student at Illinois and is now a postdoctoral fellow at Stanford University. “I’m in California now, and there’s a lot of talk about the drought and how to tackle it. I’m very hopeful that this work can help the designers of desalination plants. This type of thin membrane can increase return on investment because they are much more energy efficient.”

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

Water desalination with a single-layer MoS2 nanopore by Mohammad Heiranian, Amir Barati Farimani, & Narayana R. Aluru. Nature Communications 6, Article number: 8616 doi:10.1038/ncomms9616 Published 14 October 2015

Graphene membranes

In a July 13, 2015 essay on Nanotechnology Now, Tim Harper provides an overview of the research into using graphene for water desalination and purification/remediation about which he is quite hopeful. There is no mention of an issue with interactions between water and graphene. It should be noted that Tim Harper is the Chief Executive Officer of G20, a company which produces a graphene-based solution (graphene oxide sheets), which can desalinate water and can purify/remediate it. Tim is a scientist and while you might have some hesitation given his fiscal interests, his essay is worthwhile reading as he supplies context and explanations of the science.

Heart urchin shells and air

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This is a microscale (1 millionth) rather than a nanoscale (1 billionth) story but I find the idea of shells that are mostly composed of air quite intriguing. From a Nov. 10, 2015 news item on ScienceDaily,

Materials researchers love sea creatures. Mother-of-pearl provokes ideas for smooth surfaces, clams inspire gluey substances, shark’s skin is used to develop materials that reduce drag in water, and so on. Researchers have now found a model for strong, lightweight materials by diving below the sea surface to investigate a sea urchin cousin known as the heart urchin.

A Nov. 9, 2015 University of Copenhagen press release (also on EurekAlert), which originated the news item, provides more details,

Heart urchins (Echinocardium cordatum), also known as sea potatoes, measure up to 5 cm in diameter, are heart shaped and burrow in sand. They extend a channel to feed upon organic particles from the waters above their burrow. Like “regular” sea urchins, these “irregular” heart urchins are soft creatures that use their calcium carbonate exoskeletons to protect their otherwise edible bodies from predation. And as it turns out, their shells are unexpectedly robust.

The idea to study heart urchin shells dawned upon a vacationing Müter while he was walking down a Croatian beach. The paper-thin urchin shells were washed up onto the beach, and Müter [Dirk Müter, assistant professor in the Department of Chemistry’s NanoGeoScience research group] observed that they had astonishingly few blemishes despite being so thin.

To understand the sturdy calcium carbonate shells, Müter and his colleagues used a relatively new technology called x-ray microtomography. The technique was used to create three-dimensional images of the material contents, without having to break the shells up into pieces. The x-ray images are so fine that it is possible to distinguish structures of less than one-thousandth of a millimetre. This ultra fine resolution proved decisive in coming to understand the shell’s strength.

Anyone who has ever broken a piece of chalk knows that calcium carbonate is fragile. And, heart urchin shells consist of more air than chalk. In fact, as one gets up close to the shell material, it begins to resemble soapsuds. The material consists of an incredible number of microscopic cavities held together by slender calcium carbonate (chalk) struts. There are between 50,000 and 150,000 struts per cubic millimetre, and in some areas, the material is composed of up to 70% air.

Calcium carbonate can be many things, from unyielding marble to the soft and somewhat brittle chalk that we use to write with. While heart urchin shells and writing chalk share a similar porosity, the urchin shells are up to six times stronger than chalk. Müter’s studies demonstrate that heart urchin shells have a structure that nears a theoretical ideal for foam structure strength – a must for a creature that has evolved to withstand life under 10 metres of water and an additional 30 centimetres of sand.

Müter explains that to their great surprise, heart urchin shell strength varied between shell regions due to greater or lesser concentrations of struts within specific regions, not because of thinner or thicker struts.

“We found an example of a surprisingly simple construction principle. This is an easy way to build materials. It allows for great variation in structure and strength. And, it is very near optimal from a mechanical perspective,” states Assistant Professor Dirk Müter.

Müter and his NanoGeoScience colleagues expect that their new insights will serve to improve shock- absorbent materials among other outcomes.

Here is Müter holding up a sea potato or sea heart,

Caption: The heart urchin lives its entire life dug into the sea bottom. Its fragile looking calcium shell needs to withstand the combined pressure of half a meter of sand and a couple of meters water. Dirk Müter of University of copenhagen Department of Chemistry, discovered, that this makes it one of the toughest creatures known. Credit Photo: Jes Andersen/University of Copenhagen

Caption: The heart urchin lives its entire life dug into the sea bottom. Its fragile looking calcium shell needs to withstand the combined pressure of half a meter of sand and a couple of meters water. Dirk Müter of University of copenhagen Department of Chemistry, discovered, that this makes it one of the toughest creatures known. Credit Photo: Jes Andersen/University of Copenhagen

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

Microstructure and micromechanics of the heart urchin test from X-ray tomography by D. Müter, , H.O. Sørensen, J. Oddershede, K.N. Dalby, and S.L.S. Stipp. Acta Biomaterialia Volume 23, 1 September 2015, Pages 21–26 doi:10.1016/j.actbio.2015.05.007

This paper is behind a paywall.