Molecular robots (nanobots/nanorobots): a promising start at Oxford University

‘Baby steps’ is how they are describing the motion and the breakthrough in functional molecular robots at the University of Oxford. From a Dec. 11, 2014 news item on phys.org,

A walking molecule, so small that it cannot be observed directly with a microscope, has been recorded taking its first nanometre-sized steps.

It’s the first time that anyone has shown in real time that such a tiny object – termed a ‘small molecule walker’ – has taken a series of steps. The breakthrough, made by Oxford University chemists, is a significant milestone on the long road towards developing ‘nanorobots’.

‘In the future we can imagine tiny machines that could fetch and carry cargo the size of individual molecules, which can be used as building blocks of more complicated molecular machines; imagine tiny tweezers operating inside cells,’ said Dr Gokce Su Pulcu of Oxford University’s Department of Chemistry. ‘The ultimate goal is to use molecular walkers to form nanotransport networks,’ she says.

A Dec. 10, 2014 University of Oxford science blog post by Pete Wilton, which originated the news item, describes one of the problem with nanorobots,

However, before nanorobots can run they first have to walk. As Su explains, proving this is no easy task.

For years now researchers have shown that moving machines and walkers can be built out of DNA. But, relatively speaking, DNA is much larger than small molecule walkers and DNA machines only work in water.

The big problem is that microscopes can only detect moving objects down to the level of 10–20 nanometres. This means that small molecule walkers, whose strides are 1 nanometre long, can only be detected after taking around 10 or 15 steps. It would therefore be impossible to tell with a microscope whether a walker had ‘jumped’ or ‘floated’ to a new location rather than taken all the intermediate steps.

The post then describes how the researchers solved the problem,

… Su and her colleagues at Oxford’s Bayley Group took a new approach to detecting a walker’s every step in real time. Their solution? To build a walker from an arsenic-containing molecule and detect its motion on a track built inside a nanopore.

Nanopores are already the foundation of pioneering DNA sequencing technology developed by the Bayley Group and spinout company Oxford Nanopore Technologies. Here, tiny protein pores detect molecules passing through them. Each base disrupts an electric current passed through the nanopore by a different amount so that the DNA base ‘letters’ (A, C, G or T) can be read.

In this new research, they used a nanopore containing a track formed of five ‘footholds’ to detect how a walker was moving across it.

‘We can’t ‘see’ the walker moving, but by mapping changes in the ionic current flowing through the pore as the molecule moves from foothold to foothold we are able to chart how it is stepping from one to the other and back again,’ Su explains.

To ensure that the walker doesn’t float away, they designed it to have ‘feet’ that stick to the track by making and breaking chemical bonds. Su says: ‘It’s a bit like stepping on a carpet with glue under your shoes: with each step the walker’s foot sticks and then unsticks so that it can move to the next foothold.’ This approach could make it possible to design a machine that can walk on a variety of surfaces.

There is a video illustrating the molecular walker’s motion, (courtesy University of Oxford),

There is as noted in Wilton’s post, more work to do,

It’s quite an achievement for such a tiny machine but, as Su is the first to admit, there are many more challenges to be overcome before programmable nanorobots are a reality.

‘At the moment we don’t have much control over which direction the walker moves in; it moves pretty randomly,’ Su tells me. ‘The protein track is a bit like a mountain slope; there’s a direction that’s easier to walk in so walkers will tend to go this way. We hope to be able to harness this preference to build tracks that direct a walker where we want it to go.’

The next challenge after that will be for a walker to make itself useful by, for instance, carrying a cargo: there’s already space for it to carry a molecule on its ‘head’ that it could then take to a desired location to accomplish a task.

Su comments: ‘We should be able to engineer a surface where we can control the movement of these walkers and observe them under a microscope through the way they interact with a very thin fluorescent layer. This would make it possible to design chips with different stations with walkers ferrying cargo between these stations; so the beginnings of a nanotransport system.’

These are the first tentative baby steps of a new technology, but they promise that there could be much bigger strides to come.

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

Continuous observation of the stochastic motion of an individual small-molecule walker by Gökçe Su Pulcu, Ellina Mikhailova, Lai-Sheung Choi, & Hagan Bayley. Nature Nanotechnology (2014) doi:10.1038/nnano.2014.264 Published online 08 December 2014

This paper is behind a paywall.

Bring ‘jazzy’ molecules to life on an app

The app accompanies book two (Molecules: The Elements and the Architecture of Everything) in a proposed trilogy about chemical elements in all their glory. A Dec. 10, 2014 news item on phys.org describes the app,

Although molecules make up everything around us, most people encounter these groups of atoms held together by chemical bonds in the pages of a textbook. They read text and see a drawing of chemical symbols or colorful circles—a one-dimensional view of the microscopic structures. Other representations have drawbacks as well: three-dimensional models are made of materials that can’t replicate the rapid and continuous molecular movement. Molecules are wiggling and jiggling in a never-ending dance, but you can’t see it, not even with the most powerful microscope.

“What is the best thing you could do to present (a molecule) to somebody?” asked Theo Gray, a scientist and author of “Molecules: The Elements and the Architecture of Everything.” “What’s the closest that you can come to actually handing it to them, so they could pick it up and look at it themselves?”

How about an app? In collaboration with the Theoretical and Computational Biophysics Group (TCBG) at the Beckman Institute at the University of Illinois, Gray’s company, Touchpress, has created an app for the Apple operating system (iOS) that brings molecules to life in a handheld device. Through the app, people can use up to eleven [?] fingers to examine in great detail more than 350 molecules, which they can also twist, turn, and tie into knots.

Gray has produced an entertaining and ‘jazzy’ video promoting his app (from theodoregray.com’s Molecules webpage where a link to the iTunes Download is provided),

A Dec. 10, 2014 Beckman Institute (University of Illinois) news release (also on EurekAlert) which originated the news item on phys.org, describes the objectives and the app itself more thoroughly,

“Every student who learns about typical molecules can do it now in a playful manner and realize that molecules are not dead and frozen, but that they move,” said Klaus Schulten, head of TCBG, and professor of physics at Illinois.

The app also allows users to vary the temperature and time scale in order to make the molecules move more quickly or more slowly. If the temperature is warm the molecules will move rapidly, while cold temperatures turn them sluggish, and absolute zero freezes them solid.

Getting molecules into everyone’s hands has been a goal for Gray. Even though Molecules is a beautifully illustrated book, Gray knows that the most stunning color photos and detailed descriptions can’t show the actual nature of molecules as well as looking at moving images of the material and the atomic motions themselves.

“In the case of molecules, you really can’t get a sense of what this stuff is like if you’re just looking at a picture: how goopy is it? Is it very runny or is it very thick? Is it like molasses or more like oil or more like water?” explained Gray.

“There’s also the fact that you can’t see molecules: they’re too small to see, and they’re too fast to perceive, but by providing an interactive simulation, you can give people really quite a good intuitive feeling for what a molecule is like and how it moves and how it behaves, and translate that into human scale.”

A chance meeting at a 2013 New Year’s Eve party between Gray and Barry Isralewitz, a TCBG research programmer, led to a discussion of molecular dynamic simulation. Isralewitz’s work with the TCBG involves simulating biological structures down to the atomic level. The group has created software packages VMD, which creates the visualizations, and NAMD, which simulates the movement of the structures. The software runs consecutively and in conjunction on powerful computing systems and is freely available to researchers around the world, who use it to model and simulate structures at detailed levels. Recently with the help of Blue Waters, a petascale supercomputer at the University of Illinois, TCBG unraveled one of the largest structures ever simulated—the HIV capsid, made up of 64 million atoms.

For the app, Touchpress created the visualizations, and TCBG provided the NAMD software. Taking the software into iOS, which can be used on iPhones and iPads, was not an easy task. The TCBG staff, including Jim Phillips, John Stone, and Christopher Mayne, among others, consulted regularly with Richard Zito, the main programmer from Touchpress, who lives in London.

“When Theo Gray came to us, he was full of enthusiasm, and we were actually a little hesitant. We didn’t know how well it would work out,” said Schulten. “But it worked very well, and in the course of putting our program onto this device, some technical challenges had to be met and in the wave of enthusiasm of doing it, we actually met those challenges.”

“We learned that our scientific software, which cost around $20 million to develop for the world’s best computers, can actually serve children and their parents in acquainting themselves with flexibility of molecules,” said Schulten.

“Now between education and entertainment we can think of using it for teaching. VMD is actually already used at many colleges for teaching, but now with this approach and having just a tablet computer, not even a laptop or a desktop workstation, we can penetrate much further with utilizing our tools for teaching than we ever did before.”

According to Gray, the app can make significant inroads into bringing molecules to the masses.

“It was particularly the combination of molecular dynamic simulation with a touch screen that makes it into sort of a magical experience that you don’t have when you’re doing it with a mouse,” said Gray. “Touch devices make things much more immediate and you have a personal connection to it. Combined with the fact that you can use multiple fingers to grab onto and move a molecule, like you would if you were actually holding it in your hands, it makes it quite a different experience and because it’s an iPad app, it’s available to anybody. I think it’s a pretty significant step toward getting the general public to have a better intuitive grasp as to what molecules are like.”

Schulten believes that the entertainment the app provides will help educate the next generation of scientists.

“Interacting with molecules makes them fun and natural, and that is a very powerful aspect of becoming familiar with the world of molecules,” said Schulten. “This is a wonderful tool that fits the landscape of the computing world that anybody can become familiar with through a cell phone and with a tablet, and we can utilize this big science for teaching the next generation.”

Molecules is the second volume in a proposed trilogy; The Elements: A Visual Exploration of Every Known Atom in the Universe was the first. Gray hopes that his next book Reactions and accompanying app can be as successful as Molecules.

“I think the most important thing, really,” said Gray, “is the fact that this technology has existed for quite some time, a couple of decades, but it’s really been locked up in labs, as it were—not because it wasn’t possible to bring it out to a more wide accessibility, but just because no one had thought of a good context to do that in, and maybe have the idea that it was possible to port them to a touch screen device.”

The app is available on iTunes for $13.99.

What a great idea! I wish Gray and his collaborators all the best with this project.

One last questions, is there an Android or PC desktop app in the works?

Postdoctoral position for Cosmopolitanism in Science project in Halifax, Nova Scotia, Canada)

It seems to be the week for job postings. After months and months with nothing, I stumble across two in one week. The latest comes from the Situating Science research cluster (more about the research cluster after the job posting). From a Dec. 10, 2014 Situating Science announcement,

Postdoctoral Fellowship

Science and Technology Studies (STS) / History and Philosophy of Science, Technology, Medicine (HPSTM)

University of King’s College / Dalhousie University, Halifax, NS
Duration: 1 year, with option to renew for second year pending budget and project restrictions and requirements
Application Deadline: Monday March 2 2015

The University of King’s College and Dalhousie University announce a postdoctoral fellowship award in Science and Technology Studies (STS)/ History and Philosophy of Science, Technology and Medicine (HPSTM), associated with the SSHRC [Canada Social Sciences and Humanities Research Council] Partnership Development Grant, “Cosmopolitanism and the Local in Science and Nature: Creating an East/West Partnership,” a partnership development between institutions in Canada, India and Southeast Asia aimed at establishing an East/West research network on “Cosmopolitanism” in science. The project closely examines the ideas, processes and negotiations that inform the development of science and scientific cultures within an increasingly globalized landscape. A detailed description of the project can be found at: www.CosmoLocal.org.

Funding and Duration:
The position provides a base salary equivalent to $35,220 plus benefits (EI, CPP, Medical and Dental), and with the possibility of augmenting the salary through teaching or other awards, depending on the host department. The fellow would be entitled to benefits offered by University of King’s College or Dalhousie University. The successful applicant will begin their 12-month appointment between April 1st and July 1st, 2015, subject to negotiation and candidate’s schedule. Contingent on budget and project requirements, the fellowship may be extended for a second year with an annual increase as per institutional standards.

Eligibility:
The appointment will be housed at University of King’s College and/or in one of the departments of the Faculty of Arts and Social Sciences at Dalhousie University. The successful applicant is expected to have completed a Ph.D. in STS, HPS or a cognate field, within the last five years and before taking up the fellowship. Please note that the Postdoctoral Fellowship can only be held at Dalhousie University in the six years following completion of his or her PhD. For example a person who finished his or her PhD in 2010 is eligible to be a Postdoctoral Fellow until December 2016.

In addition to carrying out independent or collaborative research under the supervision of one or more of the Cosmopolitanism co-applicants, the successful candidate will be expected to take a leadership role in the Cosmopolitanism project, to actively coordinate the development of the project, and participate in its activities as well as support networking and outreach.International candidates need a work permit and SIN.

Research:
While the research topic is open and we encourage applications from a wide range of subfields, we particularly welcome candidates with expertise and interest in the topics addressed in the Cosmopolitanism project. The candidate will be expected to work under the supervision of one of the Cosmopolitanism co-applicants. Information on each is available on the “About” page of the project’s website (www.CosmoLocal.org).

Application:

Full applications will contain:
1.     Cover letter that includes a description of current research projects,
2.     Research plan for post-doctoral work. Include how the proposed research fits within the Cosmopolitanism project’s scope, and which co-applicant with whom you wish to work.
3.     Academic CV,
4.     Writing sample,
5.     Names and contact information of three referees.

Applications can be submitted in either hardcopy or emailed as PDF documents:

Hardcopy:
Dr. Gordon McOuat
Cosmopolitanism and the Local Project
University of King’s College
6350 Coburg Road
Halifax, NS.  B3H 2A1
CANADA

News of this partnership is exciting especially in light of the objectives as described on the Cosmopolitanism & the Local in Science & Nature website’s About Us page,

Specifically, the project will:

  1. Expose a hitherto largely Eurocentric scholarly community in Canada to widening international perspectives and methods, [emphasis mine]
  2. Build on past successes at border-crossings and exchanges between the participants,
  3. Facilitate a much needed nation-wide organization and exchange amongst Indian and South East Asian scholars, in concert with their Canadian counterparts, by integrating into an international network,
  4. Open up new perspectives on the genesis and place of globalized science, and thereby
  5. Offer alternative ways to conceptualize and engage globalization itself, and especially the globalization of knowledge and science.
  6. Bring the managerial team together for joint discussion, research exchange, leveraging and planning – all in the aid of laying the grounds of a sustainable partnership

I’m not sure ‘expose’ is the verb I’d use here since it’s perfectly obvious that the Canadian scholarly community is eurocentric. For confirmation all you have to do is look at the expert panels convened by the Council of Canadian Academies for their various assessments (e.g. The Expert Panel on the State of Canada’s Science Culture). Instead of ‘expose’, I’d use ‘Shift conscious and unconscious assumptions within a largely eurocentric Canadian scholarly community to widening perspectives’.

As for Situating Science, there is this (from its About Us page; Note: Links have been removed),

Created in 2007 with the generous funding of the Social Sciences and Humanities Research Council of Canada Strategic Knowledge Cluster grant, Situating Science is a seven-year project promoting communication and collaboration among humanists and social scientists that are engaged in the study of science and technology.

At the end of our 7 years, we can boast a number of collaborative successes. We helped organize and support over 20 conferences and workshops, 4 national lecture series, 6 summer schools, and dozens of other events. Our network helped facilitate the development of 4 new programs of study at partner institutions. We leveraged more than one million dollars from Nodal partner universities plus more than one million dollars from over 200 supporting and partnering organizations. We hired over 30 students and 9 postdoctoral fellows. The events resulted in over 60 videos and podcasts as well as dozens of student blogs and over 50 publications.

I see the Situating Science project is coming to an end and I’m sorry to see it go. I think I will write more about Situating Science in one of my end-of-year posts. Getting back to the postdoc position, good luck to all the applicants!

Projecting beams of light from contact lenses courtesy of Princeton University (US)

Princeton University’s 3D printed contact lenses with LED (light-emitting diodes) included are not meant for use by humans or other living beings but they are a flashy demonstration. From a Dec. 10, 2014 news item on phys.org,

As part of a project demonstrating new 3-D printing techniques, Princeton researchers have embedded tiny light-emitting diodes into a standard contact lens, allowing the device to project beams of colored light.

Michael McAlpine, the lead researcher, cautioned that the lens is not designed for actual use—for one, it requires an external power supply. Instead, he said the team created the device to demonstrate the ability to “3-D print” electronics into complex shapes and materials.

“This shows that we can use 3-D printing to create complex electronics including semiconductors,” said McAlpine, an assistant professor of mechanical and aerospace engineering. “We were able to 3-D print an entire device, in this case an LED.”

A Dec. 9, 2014 Princeton University news release by John Sullivan, which originated the news item, describes the 3D lens, the objectives for this project, and an earlier project involving a ‘bionic ear’ in more detail (Note: Links have been removed),

The hard contact lens is made of plastic. The researchers used tiny crystals, called quantum dots, to create the LEDs that generated the colored light. Different size dots can be used to generate various colors.

“We used the quantum dots [also known as nanoparticles] as an ink,” McAlpine said. “We were able to generate two different colors, orange and green.”

The contact lens is also part of an ongoing effort to use 3-D printing to assemble diverse, and often hard-to-combine, materials into functioning devices. In the recent past, a team of Princeton professors including McAlpine created a bionic ear out of living cells with an embedded antenna that could receive radio signals.

Yong Lin Kong, a researcher on both projects, said the bionic ear presented a different type of challenge.

“The main focus of the bionic ear project was to demonstrate the merger of electronics and biological materials,” said Kong, a graduate student in mechanical and aerospace engineering.

Kong, the lead author of the Oct. 31 [2014] article describing the current work in the journal Nano Letters, said that the contact lens project, on the other hand, involved the printing of active electronics using diverse materials. The materials were often mechanically, chemically or thermally incompatible — for example, using heat to shape one material could inadvertently destroy another material in close proximity. The team had to find ways to handle these incompatibilities and also had to develop new methods to print electronics, rather than use the techniques commonly used in the electronics industry.

“For example, it is not trivial to pattern a thin and uniform coating of nanoparticles and polymers without the involvement of conventional microfabrication techniques, yet the thickness and uniformity of the printed films are two of the critical parameters that determine the performance and yield of the printed active device,” Kong said.

To solve these interdisciplinary challenges, the researchers collaborated with Ian Tamargo, who graduated this year with a bachelor’s degree in chemistry; Hyoungsoo Kim, a postdoctoral research associate and fluid dynamics expert in the mechanical and aerospace engineering department; and Barry Rand, an assistant professor of electrical engineering and the Andlinger Center for Energy and the Environment.

McAlpine said that one of 3-D printing’s greatest strengths is its ability to create electronics in complex forms. Unlike traditional electronics manufacturing, which builds circuits in flat assemblies and then stacks them into three dimensions, 3-D printers can create vertical structures as easily as horizontal ones.

“In this case, we had a cube of LEDs,” he said. “Some of the wiring was vertical and some was horizontal.”

To conduct the research, the team built a new type of 3-D printer that McAlpine described as “somewhere between off-the-shelf and really fancy.” Dan Steingart, an assistant professor of mechanical and aerospace engineering and the Andlinger Center, helped design and build the new printer, which McAlpine estimated cost in the neighborhood of $20,000.

McAlpine said that he does not envision 3-D printing replacing traditional manufacturing in electronics any time soon; instead, they are complementary technologies with very different strengths. Traditional manufacturing, which uses lithography to create electronic components, is a fast and efficient way to make multiple copies with a very high reliability. Manufacturers are using 3-D printing, which is slow but easy to change and customize, to create molds and patterns for rapid prototyping.

Prime uses for 3-D printing are situations that demand flexibility and that need to be tailored to a specific use. For example, conventional manufacturing techniques are not practical for medical devices that need to be fit to a patient’s particular shape or devices that require the blending of unusual materials in customized ways.

“Trying to print a cellphone is probably not the way to go,” McAlpine said. “It is customization that gives the power to 3-D printing.”

In this case, the researchers were able to custom 3-D print electronics on a contact lens by first scanning the lens, and feeding the geometric information back into the printer. This allowed for conformal 3-D printing of an LED on the contact lens.

Here’s what the contact lens looks like,

Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton, is leading a research team that uses 3-D printing to create complex electronics devices such as this light-emitting diode printed in a plastic contact lens. (Photos by Frank Wojciechowski)

Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton, is leading a research team that uses 3-D printing to create complex electronics devices such as this light-emitting diode printed in a plastic contact lens. (Photos by Frank Wojciechowski)

Also, here’s a link to and a citation for the research paper,

3D Printed Quantum Dot Light-Emitting Diodes by Yong Lin Kong, Ian A. Tamargo, Hyoungsoo Kim, Blake N. Johnson, Maneesh K. Gupta, Tae-Wook Koh, Huai-An Chin, Daniel A. Steingart, Barry P. Rand, and Michael C. McAlpine. Nano Lett., 2014, 14 (12), pp 7017–7023 DOI: 10.1021/nl5033292 Publication Date (Web): October 31, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall.

I’m always a day behind for Dexter Johnson’s postings on the Nanoclast blog (located on the IEEE [institute of Electrical and Electronics Engineers]) so I didn’t see his Dec. 11, 2014 post about these 3Dprinted LED[embedded contact lenses until this morning (Dec. 12, 2014). In any event, I’m excerpting his very nice description of quantum dots,

The LED was made out of the somewhat exotic nanoparticles known as quantum dots. Quantum dots are a nanocrystal that have been fashioned out of semiconductor materials and possess distinct optoelectronic properties, most notably fluorescence, which makes them applicable in this case for the LEDs of the contact lens.

“We used the quantum dots [also known as nanoparticles] as an ink,” McAlpine said. “We were able to generate two different colors, orange and green.”

I encourage you to read Dexter’s post as he provides additional insights based on his long-standing membership within the nanotechnology community.

Solving an iridescent mystery could lead to quantum transistors

iridescence has fascinated me (and scores of other people) since early childhood and it’s fascinating to note that scientists seems almost as enchanted as we amateurs are. The latest bit of ‘iridescent’ news comes from the University of Michigan in a Dec. 5, 2014 news item on ScienceDaily,

An odd, iridescent material that’s puzzled physicists for decades turns out to be an exotic state of matter that could open a new path to quantum computers and other next-generation electronics.

Physicists at the University of Michigan have discovered or confirmed several properties of the compound samarium hexaboride that raise hopes for finding the silicon of the quantum era. They say their results also close the case of how to classify the material–a mystery that has been investigated since the late 1960s.

A Dec. 5, 2014 University of Michigan news release, which originated the news item, provides more details about the mystery and the efforts to resolve it,

The researchers provide the first direct evidence that samarium hexaboride, abbreviated SmB6, is a topological insulator. Topological insulators are, to physicists, an exciting class of solids that conduct electricity like a metal across their surface, but block the flow of current like rubber through their interior. They behave in this two-faced way despite that their chemical composition is the same throughout.

The U-M scientists used a technique called torque magnetometry to observe tell-tale oscillations in the material’s response to a magnetic field that reveal how electric current moves through it. Their technique also showed that the surface of samarium hexaboride holds rare Dirac electrons, particles with the potential to help researchers overcome one of the biggest hurdles in quantum computing.

These properties are particularly enticing to scientists because SmB6 is considered a strongly correlated material. Its electrons interact more closely with one another than most solids. This helps its interior maintain electricity-blocking behavior.

This deeper understanding of samarium hexaboride raises the possibility that engineers might one day route the flow of electric current in quantum computers like they do on silicon in conventional electronics, said Lu Li, assistant professor of physics in the College of Literature, Science, and the Arts and a co-author of a paper on the findings published in Science.

“Before this, no one had found Dirac electrons in a strongly correlated material,” Li said. “We thought strong correlation would hurt them, but now we know it doesn’t. While I don’t think this material is the answer, now we know that this combination of properties is possible and we can look for other candidates.”

The drawback of samarium hexaboride is that the researchers only observed these behaviors at ultracold temperatures.

Quantum computers use particles like atoms or electrons to perform processing and memory tasks. They could offer dramatic increases in computing power due to their ability to carry out scores of calculations at once. Because they could factor numbers much faster than conventional computers, they would greatly improve computer security.

In quantum computers, “qubits” stand in for the 0s and 1s of conventional computers’ binary code. While a conventional bit can be either a 0 or a 1, a qubit could be both at the same time—only until you measure it, that is. Measuring a quantum system forces it to pick one state, which eliminates its main advantage.

Dirac electrons, named after the English physicist whose equations describe their behavior, straddle the realms of classical and quantum physics, Li said. Working together with other materials, they could be capable of clumping together into a new kind of qubit that would change the properties of a material in a way that could be measured indirectly, without the qubit sensing it. The qubit could remain in both states.

While these applications are intriguing, the researchers are most enthusiastic about the fundamental science they’ve uncovered.

“In the science business you have concepts that tell you it should be this or that and when it’s two things at once, that’s a sign you have something interesting to find,” said Jim Allen, an emeritus professor of physics who studied samarium hexaboride for 30 years. “Mysteries are always intriguing to people who do curiosity-driven research.”

Allen thought for years that samarium hexaboride must be a flawed insulator that behaved like a metal at low temperatures because of defects and impurities, but he couldn’t align that with all of its other properties.

“The prediction several years ago about it being a topological insulator makes a lightbulb go off if you’re an old guy like me and you’ve been living with this stuff your whole life,” Allen said.

In 2010, Kai Sun, assistant professor of physics at U-M, led a group that first posited that SmB6 might be a topological insulator. He and Allen were also involved in seminal U-M experiments led by physics professor Cagliyan Kurdak in 2012 that showed indirectly that the hypothesis was correct.

“But the scientific community is always critical,” Sun said. “They want very strong evidence. We think this experiment finally provides direct proof of our theory.”

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

Two-dimensional Fermi surfaces in Kondo insulator SmB6 by G. Li, Z. Xiang, F. Yu, T. Asaba, B. Lawson, P. Cai1, C. Tinsman, A. Berkley, S. Wolgast, Y. S. Eo, Dae-Jeong Kim, C. Kurdak, J. W. Allen, K. Sun, X. H. Chen, Y. Y. Wang, Z. Fisk, and Lu Li. Science 5 December 2014: Vol. 346 no. 6214 pp. 1208-1212 DOI: 10.1126/science.1250366

This paper is behind a paywall.

Job at Society for Applied Microbiology: Corporate communications manager

Dec. 23, 2014 is the deadline for applications, should you be interested in the job of ‘Corporate communications manager’ for the Society for Applied Microbiology (SfAM). Thanks to Nancy Mendoza of the Science Public Relations group on LinkedIn for information about the job posting. The posting is also on the SFAM website,

 Closing date: 5pm (GMT), Tuesday 23 December, 2014

Circa £28.5K (Plus Pension)

Full Time, Permanent (subject to successful completion of probationary period)

Based in the Society Office, Bedford, UK

Founded in 1931, SfAM is the oldest microbiology society in the UK, and it serves microbiologists around the world.

SfAM is a limited company and a registered charity with membership numbers approaching 3000. As the voice of applied microbiology, SfAM works to advance, for the benefit of the public, the science of microbiology in its application to the environment, human and animal health, agriculture, and industry.

Value for money and a modern, innovative and progressive outlook are the Society’s core principles. A friendly society, SfAM values integrity, honesty, and respect, and seeks to promote excellence and professionalism and to inspire the next generation of microbiologists.

From its very inception, SfAM has strived to include all its membership in its activities and to foster an informal and friendly atmosphere, whilst maintaining professional excellence and achieving high standards.

This is an exciting opportunity for a communications professional to join the communications team at the Society. The Corporate Communications Manager will work alongside the Public Engagement Manager and closely with the freelance communications professional and will report directly to the Chief Executive. The CCM will create and deliver an effective corporate communications strategy aligned with the organization-wide strategic objectives as set by the Executive Committee and Chief Executive.

The Role

To create a corporate communications strategy for the Society to deliver high quality communications activity which is aligned with the wider organisational strategy.

To work with the Public Engagement Manager and the freelance communications professional to deliver the communications strategy.

To manage all aspects of corporate communications for the Society including:

Online, social media and podcasting
PR and media relations
Management of the members’ magazine, Microbiologist
Delivery of a new CRM system to enable greater efficiencies across the organization

Please apply to Mrs Julie Buchanan ([email protected]) with a CV and covering letter stating any required notice period, by 5pm (GMT) on Tuesday 23 December 2014.

Requirements

Essential

We are looking for an experienced communications professional with knowledge and understanding of effective marketing strategies.

Ideally, the successful candidate will have an appreciation of the life sciences, in particular, microbiology.

Excellent written and oral communication skills should be coupled with evidence of relationship building and interpersonal skills.

Experience of developing and managing media relations is essential, as is knowledge of development and management of website and social media communications.

Experience of contact databases and CRM is essential.

Excellent project and time management skills are essential, with proven ability to prioritize effectively and with experience of managing budgets.

The ability to work effectively and efficiently with a wide range of suppliers/freelancers/contract service providers and stakeholders is also essential.

A positive ‘can do’ attitude coupled with a commitment to continuous improvement are essential, as is an understanding and commitment to equal opportunities, non-discrimination and accessibility.

Also essential is the ability to work effectively as part of a small, professional and productive team who work with a commitment to the aims and values of the Society for Applied Microbiology.

Desirable

A relevant post graduate qualification in communications or PR.

Experience within a scientific organization.

Knowledge of, or experience in, the Learned Society sector.

Good luck!

Do Tenebrionind beetles collect dew or condensation—a water issue at the nanoscale

Up until now, the research I’ve stumbled across about Tenebrionind beetles and their water-collecting ways has been from the US but this latest work comes from a France/Spain,/UK collaboration which focused on a specific question, exactly where do these beetles harvest their water from? A Dec. 8, 2014 news item on Nanotechnology Now describes this latest research,

Understanding how a desert beetle harvests water from dew could improve drinking water collection in dew condensers

Insects are full of marvels – and this is certainly the case with a beetle from the Tenebrionind family, found in the extreme conditions of the Namib desert. Now, a team of scientists has demonstrated that such insects can collect dew on their backs – and not just fog as previously thought. This is made possible by the wax nanostructure on the surface of the beetle’s elytra. … They bring us a step closer to harvesting dew to make drinking water from the humidity in the air. This, the team hopes, can be done by improving the water yield of man-made dew condensers that mimick the nanostructure on the beetle’s back.

A Dec. 8, 2014  Springer press release (also on EurekAlert), which originated the news item, describes how this research adds to the body of knowledge about the ability to harvest water from the air,

It was not clear from previous studies whether water harvested by such beetles came from dew droplets, in addition to fog. Whereas fog is made of ready-made microdroplets floating in the air, dew appears following the cooling of a substrate below air temperature. This then turns the humidity of air into tiny droplets of water because more energy – as can be measured through infrared emissions – is sent to the atmosphere than received by it. The cooling capability is ideal, they demonstrated, because the insect’s back demonstrates near-perfect infrared emissivity.

Guadarrama-Cetina [José Guadarrama-Cetina] and colleagues also performed an image analysis of dew drops forming on the insect’s back on the surface of the elytra, which appears as a series of bumps and valleys. Dew primarily forms in the valleys endowed with a hexagonal microstructure, they found, unlike the smooth surface of the bumps. This explains how drops can slide to the insect’s mouth when they reach a critical size.

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

Dew condensation on desert beetle skin by J.M. Guadarrama-Cetina, A. Mongruel, M.-G. Medici, E. Baquero, A.R. Parker, I. Milimouk-Melnytchuk, W. González-Viñas, and D. Beysens. Eur. Phys. J. E (European Physics Journal E 2014) 37: 109, DOI 10.1140/epje/i2014-14109-y

This paper is currently (Dec. 8, 2014) open access. I do not know if this will be permanent or if access rights will change over time.

My previous postings on the topic of water and beetles have focused on US research of the Stenocara beetle (aka Namib desert beetle) which appears to be a member of the Tenebrionind family of beetles mentioned in this latest research.

The European researchers have provided an image of the beetle they were examining,

A preserved specimen of the Tenebrionind beetle (Physasterna cribripes) was used for this study, displaying the insect’s mechanisms of dew harvesting. © J.M. Guadarrama-Cetina et al.

A preserved specimen of the Tenebrionind beetle (Physasterna cribripes) was used for this study, displaying the insect’s mechanisms of dew harvesting. © J.M. Guadarrama-Cetina et al.

As for my other pieces on this topic, there’s a July 29, 2014 post, a June 18, 2014 post, and a Nov. 26, 2012 post.

Gold nanorod instabilities

A Dec. 8, 2014 news item on Nanowerk focuses on research from Australia,

Researchers at Swinburne University of Technology [Melbourne, Australia]  have discovered an instability in gold nanoparticles that is critical for their application in future technology.

Gold nanorods are important building blocks for future applications in solar cells, cancer therapy and optical circuitry.

However their stability is under question due to their peculiar reshaping behaviour below melting points.

A Dec. 8, 2014 Swinburne University of Technology press release, which originated the news item, discusses melting points and shape instabilities in the context of this research,

A solid normally does not change its shape unless it reaches its melting point, or surface melting points. It is also known that the melting point for nanoparticles is suppressed due to their size.

PhD student Adam Taylor (now a postdoctoral researcher at Swinburne) said it came as a surprise that reshaping is observed well below these melting points. Until now, no one could explain this peculiar behaviour.

“In our work, we have discovered both theoretically and experimentally that the reshaping mechanism for nanoparticles below melting point is surface atom diffusion, rather than melting,” Mr Taylor said.

Surface atom diffusion is a process involving the motion of molecules at solid material surfaces that can generally be thought of in terms of particles jumping between adjacent adsorption sites on a surface.

“Surface atom diffusion always existed in bulk solids, but this is the first evidence that its effect is enhanced at the nano-size, dominating over the traditional theory of melting,” Associate Professor James Chon, who is supervising Mr Taylor’s research, said.

Mr Taylor said the more finely nanoparticles are shaped, the less stable they become.

“This is important, for example, for solar panel manufacturers as the more needle-like these nanoparticles are shaped the less stable they become. If you put these particles into a solar panel to concentrate light they may not last long in the sun before they degrade,” Mr Taylor said.

“This discovery will be crucial for future applications of gold nanorods, as people will need to reconsider their stability when applying them to solar cells, cancer therapeutic agents and optical circuitry.”

The researchers have provided an illustration of their work,

Courtesy Swinburne University of Technology

Courtesy Swinburne University of Technology

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

Below Melting Point Photothermal Reshaping of Single Gold Nanorods Driven by Surface Diffusion by Adam B. Taylor, Arif M. Siddiquee, and James W. M. Chon. ACS Nano, Article ASAP DOI: 10.1021/nn5055283 Publication Date (Web): November 18, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall but should you be in Australia and eligible to attend, there’s another opportunity to learn more; Taylor will be presenting his work at the Australian Institute of Physics conference on December 10, 2014 in Canberra.

Spray-on solar cells from the University of Toronto (Canada)

It’s been a while since there’s been a solar cell story from the University of Toronto (U of T) and I was starting to wonder if Ted (Edward) Sargent had moved to another educational institution. The drought has ended with the announcement of three research papers being published by researchers from Sargent’s U of T laboratory. From a Dec. 5, 2014 ScienceDaily news item,

Pretty soon, powering your tablet could be as simple as wrapping it in cling wrap.

That’s Illan Kramer’s … hope. Kramer and colleagues have just invented a new way to spray solar cells onto flexible surfaces using miniscule light-sensitive materials known as colloidal quantum dots (CQDs) — a major step toward making spray-on solar cells easy and cheap to manufacture.

A Dec. 4, 2014 University of Toronto news release (also on EurekAlert) by Marit Mitchell, which originated the news item, gives a bit more detail about the technology (Note: Links have been removed),

 Solar-sensitive CQDs printed onto a flexible film could be used to coat all kinds of weirdly-shaped surfaces, from patio furniture to an airplane’s wing. A surface the size of a car roof wrapped with CQD-coated film would produce enough energy to power three 100-watt light bulbs – or 24 compact fluorescents.

He calls his system sprayLD, a play on the manufacturing process called ALD, short for atomic layer deposition, in which materials are laid down on a surface one atom-thickness at a time.

Until now, it was only possible to incorporate light-sensitive CQDs onto surfaces through batch processing – an inefficient, slow and expensive assembly-line approach to chemical coating. SprayLD blasts a liquid containing CQDs directly onto flexible surfaces, such as film or plastic, like printing a newspaper by applying ink onto a roll of paper. This roll-to-roll coating method makes incorporating solar cells into existing manufacturing processes much simpler. In two recent papers in the journals Advanced Materials and Applied Physics Letters, Kramer showed that the sprayLD method can be used on flexible materials without any major loss in solar-cell efficiency.

Kramer built his sprayLD device using parts that are readily available and rather affordable – he sourced a spray nozzle used in steel mills to cool steel with a fine mist of water, and a few regular air brushes from an art store.

“This is something you can build in a Junkyard Wars fashion, which is basically how we did it,” says Kramer. “We think of this as a no-compromise solution for shifting from batch processing to roll-to-roll.”

“As quantum dot solar technology advances rapidly in performance, it’s important to determine how to scale them and make this new class of solar technologies manufacturable,” said Professor Ted Sargent, vice-dean, research in the Faculty of Applied Science & Engineering at University of Toronto and Kramer’s supervisor. “We were thrilled when this attractively-manufacturable spray-coating process also led to superior performance devices showing improved control and purity.”

In a third paper in the journal ACS Nano, Kramer and his colleagues used IBM’s BlueGeneQ supercomputer to model how and why the sprayed CQDs perform just as well as – and in some cases better than – their batch-processed counterparts. This work was supported by the IBM Canada Research and Development Centre, and by King Abdullah University of Science and Technology.

For those who would like to see the sprayLD device,

Here are links and citation for all three papers,

Efficient Spray-Coated Colloidal Quantum Dot Solar Cells by Illan J. Kramer, James C. Minor, Gabriel Moreno-Bautista, Lisa Rollny, Pongsakorn Kanjanaboos, Damir Kopilovic, Susanna M. Thon, Graham H. Carey, Kang Wei Chou, David Zhitomirsky, Aram Amassian, and Edward H. Sargent. Advanced Materials DOI: 10.1002/adma.201403281 Article first published online: 10 NOV 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Colloidal quantum dot solar cells on curved and flexible substrates by Illan J. Kramer, Gabriel Moreno-Bautista, James C. Minor, Damir Kopilovic, and Edward H. Sargent. Appl. Phys. Lett. 105, 163902 (2014); http://dx.doi.org/10.1063/1.4898635 Published online 21 October 2014

© 2014 AIP Publishing LLC

Electronically Active Impurities in Colloidal Quantum Dot Solids by Graham H. Carey, Illan J. Kramer, Pongsakorn Kanjanaboos, Gabriel Moreno-Bautista, Oleksandr Voznyy, Lisa Rollny, Joel A. Tang, Sjoerd Hoogland, and Edward H. Sargent. ACS Nano, 2014, 8 (11), pp 11763–11769 DOI: 10.1021/nn505343e Publication Date (Web): November 6, 2014

Copyright © 2014 American Chemical Society

All three papers are behind paywalls.

Given the publication dates for the papers, this looks like an attempt to get some previously announced research noticed by sending out a summary news release using a new ‘hook’ to get attention. I hope it works for them as it must be disheartening to have your research sink into obscurity because the announcements were issued during one or more busy news cycles.

One final note, if I understand the news release correctly, this work is still largely theoretical as there don’t seem to have been any field tests.

Dumbbells at the nanoscale according to researchers at the (US) Argonne National Laboratory

Researchers at the US Dept. of Energy’s Argonne National Laboratory are providing new insight into how nanoparticles ‘grow’. From a Dec. 5, 2014 news item on Nanowerk,

Like snowflakes, nanoparticles come in a wide variety of shapes and sizes. The geometry of a nanoparticle is often as influential as its chemical makeup in determining how it behaves, from its catalytic properties to its potential as a semiconductor component.

Thanks to a new study from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, researchers are closer to understanding the process by which nanoparticles made of more than one material – called heterostructured nanoparticles – form. This process, known as heterogeneous nucleation, is the same mechanism by which beads of condensation form on a windowpane.

The scientists have provided an image which illustrates their findings,

This picture combines a transmission electron microscope image of a nanodumbbell with a gold domain oriented in direction. The seed and gold domains in the dumbbell in the image on the right are identified by geometric phase analysis. Image credit: Soon Gu Kwon.

This picture combines a transmission electron microscope image of a nanodumbbell with a gold domain oriented in direction. The seed and gold domains in the dumbbell in the image on the right are identified by geometric phase analysis. Image credit: Soon Gu Kwon.

A Dec. 4, 2014 Argonne National Laboratory news release by Jared Sagoff, which originated the news item, describes the structures being examined and the reason for doing so,

Heterostructured nanoparticles can be used as catalysts and in advanced energy conversion and storage systems. Typically, these nanoparticles are created from tiny “seeds” of one material, on top of which another material is grown.  In this study, the Argonne researchers noticed that the differences in the atomic arrangements of the two materials have a big impact on the shape of the resulting nanoparticle.

“Before we started this experiment, it wasn’t entirely clear what’s happening at the interface when one material grows on another,” said nanoscientist Elena Shevchenko of Argonne Center for Nanoscale Materials, a DOE Office of Science user facility.

In this study, the researchers observed the formation of a nanoparticle consisting of platinum and gold.  The researchers started with a platinum seed and grew gold around it. Initially, the gold covered the platinum seed’s surface uniformly, creating a type of nanoparticle known as “core-shell.” However, as more gold was deposited, it started to grow unevenly, creating a dumbbell-like structure.

Thanks to state-of-the-art X-ray analysis provided by Argonne’s Advanced Photon Source (APS), a DOE Office of Science user facility, the researchers identified the cause of the dumbbell formation as “lattice mismatch,” in which the spacing between the atoms in the two materials doesn’t align.

“Essentially, you can think of lattice mismatch as having a row of smaller boxes on the bottom layer and larger boxes on the top layer.  When you try to fit the larger boxes into the space for a smaller box, it creates an immense strain,” said Argonne physicist Byeongdu Lee.

While the lattice mismatch is only fractions of a nanometer, the effect accumulates as layer after layer of gold forms on the platinum. The mismatch can be handled by the first two layers of gold atoms – creating the core-shell effect – but afterwards it proves too much to overcome. “The arrangement of atoms is the same in the two materials, but the distance between atoms is different,” said Argonne postdoctoral researcher Soon Gu Kwon. “Eventually, this becomes unstable, and the growth of the gold becomes unevenly distributed.”

As the gold continues to accumulate on one side of the seed nanoparticle, small quantities “slide” down the side of the nanoparticle like grains of sand rolling down the side of a sand hill, creating the dumbbell shape.

The advantage of the Argonne study comes from the researchers’ ability to perform in situ observations of the material in realistic conditions using the APS. “This is the first time anyone has been able to study the kinetics of this heterogeneous nucleation process of nanoparticles in real-time under realistic conditions,” said Argonne physicist Byeongdu Lee. “The combination of two X-ray techniques gave us the ability to observe the material at both the atomic level and the nanoscale, which gave us a good view of how the nanoparticles form and transform.” All conclusions made based on the X-ray studies were further confirmed using atomic-resolution microscopy in the group of Professor Robert Klie of the University of Illinois at Chicago.

This analysis of nanoparticle formation will help to lay the groundwork for the formation of new materials with different and controllable properties, according to Shevchenko. “In order to design materials, you have to understand how these processes happen at a very basic level,” she said.

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

Heterogeneous nucleation and shape transformation of multicomponent metallic nanostructures by Soon Gu Kwon, Galyna Krylova, Patrick J. Phillips, Robert F. Klie, Soma Chattopadhyay, Tomohiro Shibata, Emilio E. Bunel, Yuzi Liu, Vitali B. Prakapenka, Byeongdu Lee, & Elena V. Shevchenko. Nature Materials (2014) doi:10.1038/nmat4115 Published online 02 November 2014

This paper is behind a paywall but there is a free preview via ReadCube Access.