Tag Archives: US

Green nanotechnology centre (meaningful science for helping humanity) launched in South Africa

On July 14, 2014, South Africa’s University of the Western Cape (UWC) launched its Centre for Green Nanotechnology. A July 23, 2014 news item on Nanowerk makes readers feel as if they were present,

The establishment of University of the Western Cape (UWC)’s Centre for Green Nanotechnology was made a reality through a positive partnership between the University of Missouri (UM) and UWC that has spanned approximately 30 years.

[Speakers at the launch of the Centre included Prof Brian O’Connell, Rector of UWC; Prof Richard Bowen Loftin, Chancellor of UM; Prof Ken Dean, Provost of UM; and Prof Ramesh Bharuthram, Deputy Vice-Chancellor of UWC.]

Green nanotechnology is a relatively new science which aims to create environmentally friendly technologies in an effort to tackle real problems. Nanotechnology has improved the design and performance of products in various areas such as electronics, medicine and medical devices, food and agriculture, cosmetics, chemicals, materials, coatings, energy and so forth. According to Prof Bharuthram, “Green nanotechnology provides an opportunity to combine the strengths of nanobioscience, nanochemistry and nanophysics towards innovative solutions for societal benefit.”

Another keynote speaker at the launch included Professor Kattesh Katti, who has been hailed as the “father of green nanotechnology” and cited as one of the 25 most influential scientists in molecular imaging in the world. Prof Katti will divide his time between the University of Missouri (where he heads up their Green Nanotechnology Centre) and UWC, where he will spend approximately 3-6 months of the year.

Prof Katti noted that nanotechnology involves various role players – including scientists, biologists and chemists – working together. During his lecture, he focused on the use of green nanotechnologies to treat cancer. While the treatment of cancer utilising green nanotechnologies is still at experimental stages, he illustrated how the use of nanotechnologies could be the treatment of the future. He explained that current drugs used to treat cancers don’t always have the desired effect as the drugs don’t always penetrate tumours effectively due to their large size and approximately 60% of drugs go away from the intended target (tumour). Nanotechnology particles, due to their small size and their functioning, have the ability to penetrate tumours much more effectively.

A July 14, 2014 UWC news release, which originated the news item, provides background about events leading to the inception of this new centre and provides insight into its purpose,

The establishment of the Centre for Green Nanotechnology started in 2008/09 when UWC embarked on developing a five-year institutional strategic plan for 2010-2014. The Institutional Operational Plan (IOP) identified eight institutional goals, which included: Goal 2 – Teaching & Learning; and Goal 3 – Research & Innovation. Prof Bharuthram explained, “The IOP articulated the need for UWC to identify emerging and established research niche areas that will not only contribute to high output in the form of research publications and graduating masters and doctoral students, but equally importantly give the University a set of distinctions that will set UWC apart from the other higher education institutions – a calculated move towards becoming a research intensive university. It is indeed fascinating that at the time UWC was engaged in this exercise, the University of Missouri was undertaking a similar comprehensive initiative which resulted in the identification and development of the five MIZZOU Advantage thematic areas. These two parallel undertakings helped to elevate the partnership between UWC and UM to hitherto unknown heights.”

UWC’s Centre for Green Nanotechnology aims to promote:

·    The development of fundamental sciences as they relate to chemistry, physics and biomedical and alternative energy aspects of green nanotechnology.

·   Research and application on indigenous phyto-chemicals and phyto-mediated technologies for the production of green nanotechnologies with applications in medicine, energy and allied disciplines.

· New green nanotechnological synthetic processes and their feasibilities at laboratory levels, pilot scale and industrial scale for mass manufacturing.

·    Green nanoparticles and green nanotechnologies in the design and development of new medical diagnostic/therapeutic agents, biological sensors, chemical sensors, smart electronic materials, nanoscale robots, environmentally benign breathing devices.

Furthermore the Centre aims to provide formal training to students at the undergraduate, graduate and post-doctoral levels in all aspects of green nanotechnology from blue sky to applied, including impact on socioeconomic development, policy development and revision.

UWC is exceptionally excited about this new venture and is proud that it continues to show great developmental strides in all academic spheres. At the launch of the Centre, Prof O’Connell said, “When there is robust engagement there is change. Knowledge and change goes together. The more ways of knowing is a more efficient way to tackle problems.”

There was a general consensus that education is the key factor in shaping our future. Prof Loftin, Chancellor of UM said, “We think of resources in terms of tangible things, but the most precious resource is human capital.

The strides that UM and UWC have made in staying current with regard to offering course studies that are new illustrates that these institutions are investing heavily in human capital and are committed to providing solutions for future challenges.

​As Prof O’Connell noted, “UWC is a metaphor for Africa. Despite being excluded and coming from a disadvantaged past, we are here to show that we can use our brain to push the boundaries.”

I wish them all the best.

Alberta’s summer of 2014 nano funding and the US nano community’s talks with the House of Representatives

I have two items concerning nanotechnology and funding. The first item features Michelle Rempel, Canada’s Minister of State for Western Economic Diversification (WD) who made two funding announcements this summer (2014) affecting the Canadian nanotechnology sector and, more specifically, the province of Alberta.

A June 20, 2014 WD Canada news release announced a $1.1M award to the University of Alberta,

Today, the Honourable Michelle Rempel, Minister of State for Western Economic Diversification, announced $1.1 million to help advance leading-edge atomic computing technologies.

Federal funds will support the University of Alberta with the purchase of an ultra-high resolution scanning tunneling microscope, which will enable researchers and scientists in western Canada and abroad to analyze electron dynamics and nanostructures at an atomic level. The first of its kind in North America, the microscope has the potential to significantly transform the semiconductor industry, as research findings aid in the prototype development and technology commercialization of new ultra low-power and low-temperature computing devices and industrial applications.

This initiative is expected to further strengthen Canada’s competitive position throughout the electronics value chain, such as microelectronics, information and communications technology, and the aerospace and defence sectors. The project will also equip graduate students with a solid foundation of knowledge and hands-on experience to become highly qualified, skilled individuals in today’s workforce.

One month later, a July 21, 2014 WD news release (hosted on the Alberta Centre for Advanced Micro and Nano Products [ACAMP]) announces this award,

Today, the Honourable Michelle Rempel, Minister of State for Western Economic Diversification, announced an investment of $3.3 million toward the purchase and installation of specialized advanced manufacturing and product development equipment at the Alberta Centre for Advanced Micro Nano Technology Products (ACAMP), as well as training on the use of this new equipment for small- and medium-sized enterprises (SMEs).

This support, combined with an investment of $800,000 from Alberta Innovates Technology Futures, will enable ACAMP to expand their services and provide businesses with affordable access to prototype manufacturing that is currently unavailable in western Canada. By helping SMEs accelerate the development and commercialization of innovative products, this project will help strengthen the global competitiveness of western Canadian technology companies.

Approximately 80 Alberta SMEs will benefit from this initiative, which is expected to result in the development of new product prototypes, the creation of new jobs in the field, as well as connections between SMEs and multi-national companies. This equipment will also assist ACAMP’s outreach activities across the western Canadian provinces.

I’m not entirely clear as to whether or not the June 2014 $1.1M award is considered part of the $3.3M award or if these are two different announcements. I am still waiting for answers to a June 20, 2014 query sent to Emily Goucher, Director of Communications to the Hon. Michelle Rempel,

Hi Emily!

Thank you for both the news release and the information about the embargo … happily not an issue at this point …

I noticed Robert Wolkow’s name in the release (I last posted about his work in a March 3, 2011 piece about his and his team’s entry into the Guinness Book of Records for the world’s smallest electron microscope tip (http://www.frogheart.ca/?tag=robert-wolkow) [Note: Wolkow was included in a list of quotees not included here in this July 29, 2014 posting]

I am assuming that the new microscope at the University of Alberta is specific to a different type of work than the one at UVic, which has a subatomic microscope (http://www.frogheart.ca/?p=10426)

Do I understand correctly that an STM is being purchased or is this an announcement of the funds and their intended use with no details about the STM available yet? After reading the news release closely, it looks to me like they do have a specific STM in mind but perhaps they don’t feel ready to make a purchase announcement yet?

If there is information about the STM that will be purchased I would deeply appreciate receiving it.

Thank you for your time.

As I wait, there’s more news from  the US as members of that country’s nanotechnology community testify at a second hearing before the House of Representatives. The first (a May 20, 2014 ‘National Nanotechnology Initiative’ hearing held before the Science, Space, and Technology
Subcommittee on Research and Technology) was mentioned in an May 23, 2014 posting  where I speculated about the community’s response to a smaller budget allocation (down to $1.5B in 2015 from $1.7B in 2014).

This second hearing is being held before the Energy and Commerce Subcommittee on Commerce, Manufacturing and Trade and features an appearance by James Tour from Rice University according to a July 28, 2014 news item on Azonano,

At the hearing, titled “Nanotechnology: Understanding How Small Solutions Drive Big Innovation,” Tour will discuss and provide written testimony on the future of nanotechnology and its impact on U.S. manufacturing and jobs. Tour is one of the most cited chemists in the country, and his Tour Group is a leader in patenting and bringing to market nanotechnology-based methods and materials.

Who: James Tour, Rice’s T.T. and W.F. Chao Chair in Chemistry and professor of materials science and nanoengineering and of computer science.

What: Exploring breakthrough nanotechnology opportunities.

When: 10:15 a.m. EDT Tuesday, July 29.

Where: Room 2322, Rayburn House Office Building, Washington, D.C.

The hearing will explore the current state of nanotechnology and the direction it is headed so that members can gain a better understanding of the policy changes that may be necessary to keep up with advancements. Ultimately, the subcommittee hopes to better understand what issues will confront regulators and how to assess the challenges and opportunities of nanotechnology.

You can find a notice for this July 2014 hearing and a list of witnesses along with their statements here. As for what a second hearing might mean within the context of the US National Nanotechnology Initiative, I cannot say with any certainty. But, this is the first time in six years of writing this blog where there have been two hearings post-budget but as a passive collector of this kind of information this may be a reflection of my information collection strategies rather than a response to a smaller budget allocation. Still, it’s interesting.

Cookies, ants, and a citizen science project plus a call for proposals for a 2015 Citizen Science Conference

My first citizen science item concerns summertime when the ants are out and about, oftentimes as uninvited participants to a picnic. Scientists at North Carolina State University (NCSU) and the University of Florida (UF) have decided to take advantage of this summer phenomenon as per a July 7, 2014 news item on ScienceDaily,

Scientists from North Carolina State University and the University of Florida have combined cookies, citizen science and robust research methods to track the diversity of ant species across the United States, and are now collaborating with international partners to get a global perspective on how ants are moving and surviving in the modern world.

“We think our School of Ants project serves as a good model for how citizen science can be used to collect more data, more quickly, from more places than a research team could do otherwise,” says Dr. Andrea Lucky, a researcher at the University of Florida who started work on the School of Ants while a postdoctoral researcher at NC State and now heads the project. Lucky is co-lead author of a paper describing the work and its early findings. “And our protocols help ensure that the data we are collecting are high quality.”

A July 7, 2014 NCSU news release (also on EurekAlert), which originated the news item, describes the various objectives for the project,

The School of Ants project was developed at NC State to help researchers get a handle on the diversity of ant species across the United States, with a particular focus on Chicago, Raleigh and New York City. In short, to discover which ant species are living where.

“But we also wanted to launch a citizen science project that both increased the public’s ecological literacy and addressed criticisms that public involvement made citizen science data unreliable,” says Dr. Amy Savage , a postdoctoral biological sciences researcher at NC State and the other co-lead author of the paper.

The research protocol, process, and outcomes are then described (from the news release),

The researchers developed a simple protocol involving Pecan Sandies cookies and sealable plastic bags, detailing precisely how the public should collect and label ant samples before shipping them to NC State or UF. [emphasis mine] This process was designed to engage the public in the aspect of the research that was easiest for non-scientists to enjoy and participate in, while also limiting the chances that the public could make mistakes that would skew the findings.

Once the samples arrive at NC State or UF, they are sorted, identified by a team of national experts and entered into a database. That information is then made publicly available in a user-friendly format on the project’s schoolofants.org site, allowing study participants to track the survey.

“This information is helping us tackle a variety of ecological and evolutionary questions, such as how ants may be evolving in urban environments, and how invasive species are spreading in the U.S.,” Savage says.

More than 1,000 participants, with samples from all 50 states, have taken part in the project since its 2011 launch – and there have already been some surprising findings.

For example, the researchers learned that a venomous invasive species, the Asian needle ant (Pachycondyla chinensis), had spread thousands of miles farther than anyone expected. Researchers knew the species had established itself in the Southeast, but study participants sent in Asian needle ant samples from as far afield as Wisconsin and Washington state.

To build on the School of Ants model, the researchers have launched collaborations with counterparts in Italy and Australia.

“We’re optimistic that this project will give us a broader view of ant diversity and how these species intersect with us, where we live and work around the world,” Lucky says.

The researchers are also working with teachers to incorporate the project into K-12 instruction modules that incorporate key elements of common core education standards. One early teacher collaboration has led to a research paper co-written by 4th and 5th graders.

“We also collaborated with a science writer to produce a free series of iBooks featuring natural history stories about the most common ants that our citizen science partners are collecting in their backyards and sidewalks,” Savage says.

“One of our big goals now is to move from collecting data and finding patterns to identifying ways that we can work with the public to figure out what is driving those patterns,” says Dr. Rob Dunn, an associate professor of biological sciences at NC State and co-author of the paper.

Not being familiar with Pecan Sandies cookies I went searching on the internet and found many recipes including this one from Martha Stewart’s website,

 Pecan Sandies

prep: 15 mins
total time: 30 mins
yield: Makes 18

Ingredients

1/2 cup (1 stick) unsalted butter, room temperature
1/2 cup packed light-brown sugar
1 1/2 teaspoons pure vanilla extract
1/4 teaspoon salt
1 cup all-purpose flour (spooned and leveled)
1 cup pecans, coarsely chopped

Cook’s Note
For best results, line cookie sheets with parchment prior to baking.
Directions

Step 1

Preheat oven to 350 degrees, with racks in upper and lower thirds. In a large bowl, using an electric mixer, beat butter and sugar until light and fluffy; beat in vanilla and salt. With mixer on low, gradually add flour, beating just until combined. Fold in pecans.

Step 2

Roll dough into 1 1/2-inch balls, and place on two baking sheets, 2 inches apart. With the dampened bottom of a glass, lightly flatten each ball.

Step 3

Bake until cookies are golden brown, 15 to 17 minutes, rotating sheets halfway through. Transfer to wire racks, and let cool.

This is what they look like (also from the Martha Stewart website),

[downloaded from http://www.marthastewart.com/342386/pecan-sandies]

[downloaded from http://www.marthastewart.com/342386/pecan-sandies]

I also checked out the School of Ants project website and found this,

The School of Ants project is a citizen-scientist driven study of the ants that live in urban areas, particularly around homes and schools. Participation is open to anyone interested!
Learn More!

Anyone can participate! Learn how to create your own sampling kit, sample your backyard or schoolyard, and get our collection back to us so that we can ID the ants and add your species list to the big School of Ants map. Together we’ll map ant diversity and species ranges across North America! Click here to get started!

There is at least one question you might want to ask before running off to collect ants, the researchers specify Keebler Pecan Sandies cookies are to be used as bait. I’m not sure how available those specific cookies and brand are in Canada, Mexico, Italy, or Australia. You may want to check with the organizers as to what alternatives might be acceptable. From the Participate webpage on the School of Ants website,

SAMPLING ANTS for the School of Ants involves placing cookie baits outdoors in green spaces (lawns, gardens, woods) and paved places (asphalt, concrete, cobblestone) for one hour on a warm day. We want to know what ants discover the baits in your neighborhood!(ALLERGY WARNING!: this activity uses Keebler Pecan Sandies cookies, which contain pecans, wheat, egg and whey).

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

Ecologists, educators, and writers collaborate with the public to assess backyard diversity in The School of Ants Project [PDF] by Andrea Lucky, Amy M. Savage, Lauren M. Nichols, Leonora Shell, Robert R. Dunn, Cristina Castracani, Donato A. Grasso, and Alessandra Mori. Ecosphere 5(7):78. http://dx.doi.org/10.1890/ES13-00364.1 Published: online July 7, 2014,

Ecosphere is an open access journal. The PDF is 23 pp.

For my second citizen science item, I have a call for proposals for the Citizen Science 2015 Conference (CS2015), February 11 & 12, 2015 in San Jose, California (prior to the 2015 AAAS [American Association for the Advancement of Science] annual meeting February 12 -16, 2015 also in San Jose). Here’s more about the Citizen Science conference from the Overview page,

Anyone involved in citizen science is invited to attend this conference. Attendees will include citizen science participants, researchers, project leaders, educators, technology specialists, evaluators, and others – representing many disciplines including astronomy, molecular biology, human and environmental health, psychology, linguistics, environmental justice, biodiversity, conservation biology, public health, genetics, engineering, cyber technology, gaming, and more – at any level of expertise. There will be opportunities throughout the conference to make connections, share insights, and help move this field forward.

We have identified six main themes for this year’s conference:

  1. Tackling Grand Challenges and Everyday Problems with Citizen Science
  2. Broadening Engagement to Foster Diversity and Inclusion
  3. Making Education and Lifelong Learning Connections (K-12, university, informal)
  4. Digital Opportunities and Challenges in Citizen Science
  5. Research on and Evaluation of the Citizen Science Experience
  6. Best Practices for Designing, Implementing, and Managing Citizen Science Projects and Programs

Here are important dates for the conference (from a June 30, 2014 email announcement),

September 15, 2014          CS2015 Deadline to submit proposals* (talks, posters, etc)
October 6, 2014                 CS2015 Proposal selection notices sent out
November 10, 2014           CS2015 Early-bird registration discount ends
February 11 & 12, 2015     CS2015 Conference

Here’s more detail, from the Presentation Styles webpage,

… Several formats are available to choose from: three styles of oral presentations; symposia/panel discussions; and posters.

Audio-visual equipment will be provided as needed for all session types except posters.

Oral Presentations
Talks allow speakers to present their work in 12 minutes, with 3 additional minutes for audience questions. Talks with similar themes will be grouped together into sessions.

Speed Talks, as the name suggests, challenge each presenter to cover his or her topic in 5 minutes or less. Following a series of speed presentations, there will be time for audience members to gather with presenters for discussion.

Story Presentations (15 minutes) emphasize sharing valuable lessons through storytelling. We especially encourage telling stories of “what didn’t work and why” and strategies for addressing challenges and unintended consequences.

Symposium Sessions or Panel Discussions (1 to 2 hours)
Every symposium or panel has one convener (most likely the person submitting this proposal); that person is responsible for organizing the session and will act as the session’s contact person with conference organizers. Additionally, that person will moderate/guide the session. Symposia/Panels may be 1-to-2 hours in length, depending on the number of proposed talks, and must include at least 15 minutes for questions and discussion with the audience.

The proposal must (1) describe the symposium or panel’s objective, (2) how it will contribute to the overall theme of the conference, and (3) include a list of proposed speakers (and, in the case of a symposium, each speaker’s topic).

Posters
Posters are designed to visually display information and engage fellow attendees in an informal way. There will be two Poster Sessions—one each day—inviting attendees to discuss posters with authors. Posters will also be on display outside of formal poster-session times. All accepted posters will be given a display space measuring 4 x 4 feet (1.2 X 1.2 meters) in the Poster Hall (no additional audio-visual aids are permitted).

You can access a link to submit your proposal here.

CS2015 is being called a pre-conference to the AAAS meeting as per the Prepare for the Conference page,

Registration
Registration details, including the conference registration fee, are not yet finalized. We are seeking funding to help support the conference and keep it affordable to all. Check back for updates, or join the CSA to receive periodic updates.

Attend Two Great Conferences
CS2015 is a pre-conference of the Annual Meeting of the American Association for the Advancement of Science (AAAS), which immediately follows our meeting at the San Jose Convention Center. The AAAS theme for 2015 is “Innovations, Information, and Imaging.” Once you have completed your CS2015 registration, you will receive instructions on how to register for the AAAS Annual Meeting (February 12-16, 2015) at the discounted rate of $235. AAAS registration will open in August 2014.

Good luck with your proposal and with your ant-captures!

Carbyne stretches from theory to reality and reveals its conundrum-type self

Rice University (Texas, US) scientists have taken a rather difficult material, carbyne, and twisted it to reveal new properties according to a July 21, 2014 news item on ScienceDaily,

Applying just the right amount of tension to a chain of carbon atoms can turn it from a metallic conductor to an insulator, according to Rice University scientists.

Stretching the material known as carbyne — a hard-to-make, one-dimensional chain of carbon atoms — by just 3 percent can begin to change its properties in ways that engineers might find useful for mechanically activated nanoscale electronics and optics.

A July 21, 2014 Rice University news release (also on EurekAlert), which originated the news item, describes carbyne and some of the difficulties the scientists addressed in their research on the material,

Until recently, carbyne has existed mostly in theory, though experimentalists have made some headway in creating small samples of the finicky material. The carbon chain would theoretically be the strongest material ever, if only someone could make it reliably.

The first-principle calculations by Yakobson and his co-authors, Rice postdoctoral researcher Vasilii Artyukhov and graduate student Mingjie Liu, show that stretching carbon chains activates the transition from conductor to insulator by widening the material’s band gap. Band gaps, which free electrons must overcome to complete a circuit, give materials the semiconducting properties that make modern electronics possible.

In their previous work on carbyne, the researchers believed they saw hints of the transition, but they had to dig deeper to find that stretching would effectively turn the material into a switch.

Each carbon atom has four electrons available to form covalent bonds. In their relaxed state, the atoms in a carbyne chain would be more or less evenly spaced, with two bonds between them. But the atoms are never static, due to natural quantum uncertainty, which Yakobson said keeps them from slipping into a less-stable Peierls distortion.

“Peierls said one-dimensional metals are unstable and must become semiconductors or insulators,” Yakobson said. “But it’s not that simple, because there are two driving factors.”

One, the Peierls distortion, “wants to open the gap that makes it a semiconductor.” The other, called zero-point vibration (ZPV), “wants to maintain uniformity and the metal state.”

Yakobson explained that ZPV is a manifestation of quantum uncertainty, which says atoms are always in motion. “It’s more a blur than a vibration,” he said. “We can say carbyne represents the uncertainty principle in action, because when it’s relaxed, the bonds are constantly confused between 2-2 and 1-3, to the point where they average out and the chain remains metallic.”

But stretching the chain shifts the balance toward alternating long and short (1-3) bonds. That progressively opens a band gap beginning at about 3 percent tension, according to the computations. The Rice team created a phase diagram to illustrate the relationship of the band gap to strain and temperature.

How carbyne is attached to electrodes also matters, Artyukhov said. “Different bond connectivity patterns can affect the metallic/dielectric state balance and shift the transition point, potentially to where it may not be accessible anymore,” he said. “So one has to be extremely careful about making the contacts.”

“Carbyne’s structure is a conundrum,” he said. “Until this paper, everybody was convinced it was single-triple, with a long bond then a short bond, caused by Peierls instability.” He said the realization that quantum vibrations may quench Peierls, together with the team’s earlier finding that tension can increase the band gap and make carbyne more insulating, prompted the new study.

“Other researchers considered the role of ZPV in Peierls-active systems, even carbyne itself, before we did,” Artyukhov said. “However, in all previous studies only two possible answers were being considered: either ‘carbyne is semiconducting’ or ‘carbyne is metallic,’ and the conclusion, whichever one, was viewed as sort of a timeless mathematical truth, a static ‘ultimate verdict.’ What we realized here is that you can use tension to dynamically go from one regime to the other, which makes it useful on a completely different level.”

Yakobson noted the findings should encourage more research into the formation of stable carbyne chains and may apply equally to other one-dimensional chains subject to Peierls distortions, including conducting polymers and charge/spin density-wave materials.

According to the news release the research was funded by the U.S. Air Force Office of Scientific Research, the Office of Naval Research Multidisciplinary University Research Initiative, and the Robert Welch Foundation. (I can’t recall another instance of the air force and the navy funding the same research.) In any event, here’s a link to and a citation for the paper,

Mechanically Induced Metal–Insulator Transition in Carbyne by Vasilii I. Artyukhov, Mingjie Liu, and Boris I. Yakobson. Nano Lett., Article ASAP DOI: 10.1021/nl5017317 Publication Date (Web): July 3, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall.

The researchers have provided an image to illustrate their work,

[downloaded from http://pubs.acs.org/doi/abs/10.1021/nl5017317]

[downloaded from http://pubs.acs.org/doi/abs/10.1021/nl5017317]

I’m not sure what the bird is doing in the image but it caught my fancy. There is another less whimsical illustration (you can see it in the  July 21, 2014 news item on ScienceDaily) and I believe the same caption can be used for the one I’ve chosen from the journal’s abstract page, “Carbyne chains of carbon atoms can be either metallic or semiconducting, according to first-principle calculations by scientists at Rice University. Stretching the chain dimerizes the atoms, opening a band gap between the pairs. Credit: Vasilii Artyukhov/Rice University.”

I last wrote about carbyne in an Oct. 9, 2013 posting where I noted that the material was unlikely to dethrone graphene as it didn’t appear to have properties useful in electronic applications. It seems the scientists have proved otherwise, at least in the laboratory.

Transmetalation, substituting one set of metal atoms for another set

Transmetalation bears a resemblance of sorts to transmutation. While the chemists from the University of Oregon aren’t turning lead to gold through an alchemical process they are switching out individual metal atoms, aluminum for indium. From a July 21, 2014 news item on ScienceDaily,

The yield so far is small, but chemists at the University of Oregon have developed a low-energy, solution-based mineral substitution process to make a precursor to transparent thin films that could find use in electronics and alternative energy devices.

A paper describing the approach is highlighted on the cover of the July 21 [2014] issue of the journal Inorganic Chemistry, which draws the most citations of research in the inorganic and nuclear chemistry fields. [emphasis mine] The paper was chosen by the American Chemical Society journal as an ACS Editor’s Choice for its potential scientific and broad public interest when it initially published online.

One observation unrelated to the research, the competition amongst universities seems to be heating up. While journals often tout their impact factor, it’s usually more discreetly than in what amounts to a citation in the second paragraph of the university news release, which originated the news item.

The July 21, 2014 University of Oregon news release (also on EurekAlert), describes the work in more detail,

The process described in the paper represents a new approach to transmetalation, in which individual atoms of one metal complex — a cluster in this case — are individually substituted in water. For this study, Maisha K. Kamunde-Devonish and Milton N. Jackson Jr., doctoral students in the Department of Chemistry and Biochemistry, replaced aluminum atoms with indium atoms.

The goal is to develop inorganic clusters as precursors that result in dense thin films with negligible defects, resulting in new functional materials and thin-film metal oxides. The latter would have wide application in a variety of electronic devices.

“Since the numbers of compounds that fit this bill is small, we are looking at transmetelation as a method for creating new precursors with new combinations of metals that would circumvent barriers to performance,” Kamunde-Devonish said.

Components in these devices now use deposition techniques that require a lot of energy in the form of pressure or temperature. Doing so in a more green way — reducing chemical waste during preparation — could reduce manufacturing costs and allow for larger-scale materials, she said.

“In essence,” said co-author Darren W. Johnson, a professor of chemistry, “we can prepare one type of nanoscale cluster compound, and then step-by-step substitute out the individual metal atoms to make new clusters that cannot be made by direct methods. The cluster we report in this paper serves as an excellent solution precursor to make very smooth thin films of amorphous aluminum indium oxide, a semiconductor material that can be used in transparent thin-film transistors.”

Transmetalation normally involves a reaction done in organic chemistry in which the substitution of metal ions generates new metal-carbon bonds for use in catalytic systems and to synthesize new metal complexes.

“This is a new way to use the process,” Kamunde-Devonish said, “Usually you take smaller building blocks and put them together to form a mix of your basic two or three metals. Instead of building a house from the ground up, we’re doing some remodeling. In everyday life that happens regularly, but in chemistry it doesn’t happen very often. We’ve been trying to make materials, compounds, anything that can be useful to improve the processes to make thin films that find application in a variety of electronic devices.”

The process, she added, could be turned into a toolbox that allows for precise substitutions to generate specifically desired properties. “Currently, we can only make small amounts,” she said, “but the fact that we can do this will allow us to get a fundamental understanding of how this process happens. The technology is possible already. It’s just a matter of determining if this type of material we’ve produced is the best for the process.”

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

Transmetalation of Aqueous Inorganic Clusters: A Useful Route to the Synthesis of Heterometallic Aluminum and Indium Hydroxo—Aquo Clusters by Maisha K. Kamunde-Devonish, Milton N. Jackson, Jr., Zachary L. Mensinger, Lev N. Zakharov, and Darren W. Johnson. Inorg. Chem., 2014, 53 (14), pp 7101–7105 DOI: 10.1021/ic403121r Publication Date (Web): April 18, 2014

Copyright © 2014 American Chemical Society

This paper appears to be open access (I was able to view the HTML version when I clicked).

Gold on the brain, a possible nanoparticle delivery system for drugs

A July 21, 2014 news item on Nanowerk describes special gold nanoparticles that could make drug delivery to cells easier,

A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells.

A new study from MIT materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons.

A July 21, 2014 MIT (Massachusetts Institute of Technology) news release (also on EurekAlert), which originated the news item, provides more details,

The findings suggest possible strategies for designing nanoparticles — made from gold or other materials — that could get into cells even more easily.

“We’ve identified a type of mechanism that might be more prevalent than is currently known,” says Reid Van Lehn, an MIT graduate student in materials science and engineering and one of the paper’s lead authors. “By identifying this pathway for the first time it also suggests not only how to engineer this particular class of nanoparticles, but that this pathway might be active in other systems as well.”

The paper’s other lead author is Maria Ricci of École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. The research team, led by Alfredo Alexander-Katz, an associate professor of materials science and engineering, and Francesco Stellacci from EPFL, also included scientists from the Carlos Besta Institute of Neurology in Italy and Durham University in the United Kingdom.

Most nanoparticles enter cells through endocytosis, a process that traps the particles in intracellular compartments, which can damage the cell membrane and cause cell contents to leak out. However, in 2008, Stellacci, who was then at MIT, and Darrell Irvine, a professor of materials science and engineering and of biological engineering, found that a special class of gold nanoparticles coated with a mix of molecules could enter cells without any disruption.

“Why this was happening, or how this was happening, was a complete mystery,” Van Lehn says.

Last year, Alexander-Katz, Van Lehn, Stellacci, and others discovered that the particles were somehow fusing with cell membranes and being absorbed into the cells. In their new study, they created detailed atomistic simulations to model how this happens, and performed experiments that confirmed the model’s predictions.

Gold nanoparticles used for drug delivery are usually coated with a thin layer of molecules that help tune their chemical properties. Some of these molecules, or ligands, are negatively charged and hydrophilic, while the rest are hydrophobic. The researchers found that the particles’ ability to enter cells depends on interactions between hydrophobic ligands and lipids found in the cell membrane.

Cell membranes consist of a double layer of phospholipid molecules, which have hydrophobic lipid tails and hydrophilic heads. The lipid tails face in toward each other, while the hydrophilic heads face out.

In their computer simulations, the researchers first created what they call a “perfect bilayer,” in which all of the lipid tails stay in place within the membrane. Under these conditions, the researchers found that the gold nanoparticles could not fuse with the cell membrane.

However, if the model membrane includes a “defect” — an opening through which lipid tails can slip out — nanoparticles begin to enter the membrane. When these lipid protrusions occur, the lipids and particles cling to each other because they are both hydrophobic, and the particles are engulfed by the membrane without damaging it.

In real cell membranes, these protrusions occur randomly, especially near sites where proteins are embedded in the membrane. They also occur more often in curved sections of membrane, because it’s harder for the hydrophilic heads to fully cover a curved area than a flat one, leaving gaps for the lipid tails to protrude.

“It’s a packing problem,” Alexander-Katz says. “There’s open space where tails can come out, and there will be water contact. It just makes it 100 times more probable to have one of these protrusions come out in highly curved regions of the membrane.”

This phenomenon appears to mimic a process that occurs naturally in cells — the fusion of vesicles with the cell membrane. Vesicles are small spheres of membrane-like material that carry cargo such as neurotransmitters or hormones.

The similarity between absorption of vesicles and nanoparticle entry suggests that cells where a lot of vesicle fusion naturally occurs could be good targets for drug delivery by gold nanoparticles. The researchers plan to further analyze how the composition of the membranes and the proteins embedded in them influence the absorption process in different cell types. “We want to really understand all the constraints and determine how we can best design nanoparticles to target particular cell types, or regions of a cell,” Van Lehn says.

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

Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes by Reid C. Van Lehn, Maria Ricci, Paulo H.J. Silva, Patrizia Andreozzi, Javier Reguera, Kislon Voïtchovsky, Francesco Stellacci, & Alfredo Alexander-Katz. Nature Communications 5, Article number: 4482 doi:10.1038/ncomms5482 Published 21 July 2014

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

I last featured this multi-country team’s work on gold nanoparticles in an Aug. 23, 2013 posting.

Steampower via nanotechnology

It seems that researchers at MIT (Massachusetts Institute of Technology (US) have been inspired by steam punk, of a sort. From a July 21, 2014 news item on Nanowerk,

A new material structure developed at MIT generates steam by soaking up the sun.

The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.

The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation. What’s more, the setup loses very little heat in the process, and can produce steam at relatively low solar intensity. This would mean that, if scaled up, the setup would likely not require complex, costly systems to highly concentrate sunlight.

A July 21, 2014 MIT news release, which originated the news item, details the research,

Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, says the spongelike structure can be made from relatively inexpensive materials — a particular advantage for a variety of compact, steam-powered applications.

“Steam is important for desalination, hygiene systems, and sterilization,” says Ghasemi, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”

Today, solar-powered steam generation involves vast fields of mirrors or lenses that concentrate incoming sunlight, heating large volumes of liquid to high enough temperatures to produce steam. However, these complex systems can experience significant heat loss, leading to inefficient steam generation.

Recently, scientists have explored ways to improve the efficiency of solar-thermal harvesting by developing new solar receivers and by working with nanofluids. The latter approach involves mixing water with nanoparticles that heat up quickly when exposed to sunlight, vaporizing the surrounding water molecules as steam. But initiating this reaction requires very intense solar energy — about 1,000 times that of an average sunny day.

By contrast, the MIT approach generates steam at a solar intensity about 10 times that of a sunny day — the lowest optical concentration reported thus far. The implication, the researchers say, is that steam-generating applications can function with lower sunlight concentration and less-expensive tracking systems.

“This is a huge advantage in cost-reduction,” Ghasemi says. “That’s exciting for us because we’ve come up with a new approach to solar steam generation.”

The approach itself is relatively simple: Since steam is generated at the surface of a liquid, Ghasemi looked for a material that could both efficiently absorb sunlight and generate steam at a liquid’s surface.

After trials with multiple materials, he settled on a thin, double-layered, disc-shaped structure. Its top layer is made from graphite that the researchers exfoliated by placing the material in a microwave. The effect, Chen says, is “just like popcorn”: The graphite bubbles up, forming a nest of flakes. The result is a highly porous material that can better absorb and retain solar energy.

The structure’s bottom layer is a carbon foam that contains pockets of air to keep the foam afloat and act as an insulator, preventing heat from escaping to the underlying liquid. The foam also contains very small pores that allow water to creep up through the structure via capillary action.

As sunlight hits the structure, it creates a hotspot in the graphite layer, generating a pressure gradient that draws water up through the carbon foam. As water seeps into the graphite layer, the heat concentrated in the graphite turns the water into steam. The structure works much like a sponge that, when placed in water on a hot, sunny day, can continuously absorb and evaporate liquid.

The researchers tested the structure by placing it in a chamber of water and exposing it to a solar simulator — a light source that simulates various intensities of solar radiation. They found they were able to convert 85 percent of solar energy into steam at a solar intensity 10 times that of a typical sunny day.

Ghasemi says the structure may be designed to be even more efficient, depending on the type of materials used.

“There can be different combinations of materials that can be used in these two layers that can lead to higher efficiencies at lower concentrations,” Ghasemi says. “There is still a lot of research that can be done on implementing this in larger systems.”

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

Solar steam generation by heat localization by Hadi Ghasemi, George Ni, Amy Marie Marconnet, James Loomis, Selcuk Yerci, Nenad Miljkovic, & Gang Chen. Nature Communications 5, Article number: 4449 doi:10.1038/ncomms5449 Published 21 July 2014

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

Mathematicians, political scientists, and cake cutting

If you have a sibling, you’ve likely fought at least once over who got the biggest or ‘best’ piece of cake.  (I do and I did.) In any event, it seems that mathematicians and political scientists have been working on a scheme to avoid disputes over cake.

[downloaded from http://link.springer.com/article/10.1007%2Fs00283-013-9442-0#page-1]

A July 16, 2014 Springer news release (also on EurekAlert) describes the quest for fairly sized cake slices and how that might apply to real life issues such as sharing property,

The next time your children quibble about who gets to eat which part of a cake, call in some experts on the art of sharing. Mathematician Julius Barbanel of Union College, and political scientist Steven Brams of New York University, both in the US, published an algorithm in Springer’s The Mathematical Intelligencer by which they show how to optimally share cake between two people efficiently, in equal pieces and in such a way that no one feels robbed.

The cut-and-choose method to share divisible goods has been regarded as fair and envy-free since Biblical times, when Abraham divided land equally, and Lot could choose the part he wanted. But being free of envy is not the only consideration when sharing something. What happens when more than two cuts can be made, or when people prefer different, specific sections of whatever is to be divided? Barbanel and Brams believe that with a giveback procedure it is possible to make a perfect division between two people that is efficient, equitable and void of jealousy.

An objective referee (such as a Mom or a computer) is essential to the plan. The potential cake eaters first tell the referee which parts of the delicacy they value most. In mathematical terms these are called someone’s probability density functions, or pdfs. The referee then marks out the cake at all points were the pdfs of the disgruntled would-be cake eaters cross, and assigns portions. If at this point the two parties receive the same size of cake, the task is over. If not, the giveback process starts.

The party who received the larger part of the cake during the first round must give a part of it back to the other person, starting with those parts in which the ratio of their pdfs is the smallest. This goes on until the parties value their portions equally, and have the same volume of cake to eat. This method only works with a finite number of cuts if the players’ pdfs are straight-lined, or are so-called piecewise linear sections.

The researchers believe the method can be used to share cake and other divisible goods such as land. In the case of beachfront property being co-owned by two developers, for example, it can help to determine who gets what strips of land to build on based on the pieces of land they value most.

“This allocation is not only equitable but also envy-free and efficient – that is, perfect,” says Barbanel.

“This approach focuses on proving the existence of efficient and envy-free divisions, not on providing algorithms to finding them,” emphasizes Brams.

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

Two-Person Cake Cutting: The Optimal Number of Cuts by Julius B. Barbanel and Steven J. Brams. The Mathematical Intelligencer March 2014 DOI 10.1007/s00283-013-9442.

This paper is behind a paywall although there is a free preview available and a special summer discount (30%) on the purchase price until July 31, 2014.

Nanophotonics transforms Raman spectroscopy at Rice University (US)

This new technique for sensing molecules is intriguing. From a July 15, 2014 news item on Azonano,

Nanophotonics experts at Rice University [Texas, US] have created a unique sensor that amplifies the optical signature of molecules by about 100 billion times. Newly published tests found the device could accurately identify the composition and structure of individual molecules containing fewer than 20 atoms.

The new imaging method, which is described this week in the journal Nature Communications, uses a form of Raman spectroscopy in combination with an intricate but mass reproducible optical amplifier. Researchers at Rice’s Laboratory for Nanophotonics (LANP) said the single-molecule sensor is about 10 times more powerful that previously reported devices.

A July 15, 2014 Rice University news release (also on EurekAlert), which originated the news item, provides more detail about the research,

“Ours and other research groups have been designing single-molecule sensors for several years, but this new approach offers advantages over any previously reported method,” said LANP Director Naomi Halas, the lead scientist on the study. “The ideal single-molecule sensor would be able to identify an unknown molecule — even a very small one — without any prior information about that molecule’s structure or composition. That’s not possible with current technology, but this new technique has that potential.”

The optical sensor uses Raman spectroscopy, a technique pioneered in the 1930s that blossomed after the advent of lasers in the 1960s. When light strikes a molecule, most of its photons bounce off or pass directly through, but a tiny fraction — fewer than one in a trillion — are absorbed and re-emitted into another energy level that differs from their initial level. By measuring and analyzing these re-emitted photons through Raman spectroscopy, scientists can decipher the types of atoms in a molecule as well as their structural arrangement.

Scientists have created a number of techniques to boost Raman signals. In the new study, LANP graduate student Yu Zhang used one of these, a two-coherent-laser technique called “coherent anti-Stokes Raman spectroscopy,” or CARS. By using CARS in conjunction with a light amplifier made of four tiny gold nanodiscs, Halas and Zhang were able to measure single molecules in a powerful new way. LANP has dubbed the new technique “surface-enhanced CARS,” or SECARS.

“The two-coherent-laser setup in SECARS is important because the second laser provides further amplification,” Zhang said. “In a conventional single-laser setup, photons go through two steps of absorption and re-emission, and the optical signatures are usually amplified around 100 million to 10 billion times. By adding a second laser that is coherent with the first one, the SECARS technique employs a more complex multiphoton process.”

Zhang said the additional amplification gives SECARS the potential to address most unknown samples. That’s an added advantage over current techniques for single-molecule sensing, which generally require a prior knowledge about a molecule’s resonant frequency before it can be accurately measured.

Another key component of the SECARS process is the device’s optical amplifier, which contains four tiny gold discs in a precise diamond-shaped arrangement. The gap in the center of the four discs is about 15 nanometers wide. Owing to an optical effect called a “Fano resonance,” the optical signatures of molecules caught in that gap are dramatically amplified because of the efficient light harvesting and signal scattering properties of the four-disc structure.

Fano resonance requires a special geometric arrangement of the discs, and one of LANP’s specialties is the design, production and analysis of Fano-resonant plasmonic structures like the four-disc “quadrumer.” In previous LANP research, other geometric disc structures were used to create powerful optical processors.

Zhang said the quadrumer amplifiers are a key to SECARS, in part because they are created with standard e-beam lithographic techniques, which means they can be easily mass-produced.

“A 15-nanometer gap may sound small, but the gap in most competing devices is on the order of 1 nanometer,” Zhang said. “Our design is much more robust because even the smallest defect in a one-nanometer device can have significant effects. Moreover, the larger gap also results in a larger target area, the area where measurements take place. The target area in our device is hundreds of times larger than the target area in a one-nanometer device, and we can measure molecules anywhere in that target area, not just in the exact center.”

Halas, the Stanley C. Moore Professor in Electrical and Computer Engineering and a professor of biomedical engineering, chemistry, physics and astronomy at Rice, said the potential applications for SECARS include chemical and biological sensing as well as metamaterials research. She said scientific labs are likely be the first beneficiaries of the technology.

“Amplification is important for sensing small molecules because the smaller the molecule, the weaker the optical signature,” Halas said. “This amplification method is the most powerful yet demonstrated, and it could prove useful in experiments where existing techniques can’t provide reliable data.”

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

Coherent anti-Stokes Raman scattering with single-molecule sensitivity using a plasmonic Fano resonance by Yu Zhang, Yu-Rong Zhen, Oara Neumann, Jared K. Day, Peter Nordlander & Naomi J. Halas. Nature Communications 5, Article number: 4424 doi:10.1038/ncomms5424 Published 14 July 2014

This paper is behind a paywall.

Squishy but rigid robots from MIT (Massachusetts Institute of Technology)

A July 14, 2014 news item on ScienceDaily MIT (Massachusetts Institute of Technology) features robots that mimic mice and other biological constructs or, if you prefer, movie robots,

In the movie “Terminator 2,” the shape-shifting T-1000 robot morphs into a liquid state to squeeze through tight spaces or to repair itself when harmed.

Now a phase-changing material built from wax and foam, and capable of switching between hard and soft states, could allow even low-cost robots to perform the same feat.

The material — developed by Anette Hosoi, a professor of mechanical engineering and applied mathematics at MIT, and her former graduate student Nadia Cheng, alongside researchers at the Max Planck Institute for Dynamics and Self-Organization and Stony Brook University — could be used to build deformable surgical robots. The robots could move through the body to reach a particular point without damaging any of the organs or vessels along the way.

A July 14, 2014 MIT news release (also on EurekAlert), which originated the news item, describes the research further by referencing both octopuses and jello,

Working with robotics company Boston Dynamics, based in Waltham, Mass., the researchers began developing the material as part of the Chemical Robots program of the Defense Advanced Research Projects Agency (DARPA). The agency was interested in “squishy” robots capable of squeezing through tight spaces and then expanding again to move around a given area, Hosoi says — much as octopuses do.

But if a robot is going to perform meaningful tasks, it needs to be able to exert a reasonable amount of force on its surroundings, she says. “You can’t just create a bowl of Jell-O, because if the Jell-O has to manipulate an object, it would simply deform without applying significant pressure to the thing it was trying to move.”

What’s more, controlling a very soft structure is extremely difficult: It is much harder to predict how the material will move, and what shapes it will form, than it is with a rigid robot.

So the researchers decided that the only way to build a deformable robot would be to develop a material that can switch between a soft and hard state, Hosoi says. “If you’re trying to squeeze under a door, for example, you should opt for a soft state, but if you want to pick up a hammer or open a window, you need at least part of the machine to be rigid,” she says.

Compressible and self-healing

To build a material capable of shifting between squishy and rigid states, the researchers coated a foam structure in wax. They chose foam because it can be squeezed into a small fraction of its normal size, but once released will bounce back to its original shape.

The wax coating, meanwhile, can change from a hard outer shell to a soft, pliable surface with moderate heating. This could be done by running a wire along each of the coated foam struts and then applying a current to heat up and melt the surrounding wax. Turning off the current again would allow the material to cool down and return to its rigid state.

In addition to switching the material to its soft state, heating the wax in this way would also repair any damage sustained, Hosoi says. “This material is self-healing,” she says. “So if you push it too far and fracture the coating, you can heat it and then cool it, and the structure returns to its original configuration.”

To build the material, the researchers simply placed the polyurethane foam in a bath of melted wax. They then squeezed the foam to encourage it to soak up the wax, Cheng says. “A lot of materials innovation can be very expensive, but in this case you could just buy really low-cost polyurethane foam and some wax from a craft store,” she says.

In order to study the properties of the material in more detail, they then used a 3-D printer to build a second version of the foam lattice structure, to allow them to carefully control the position of each of the struts and pores.

When they tested the two materials, they found that the printed lattice was more amenable to analysis than the polyurethane foam, although the latter would still be fine for low-cost applications, Hosoi says.

The wax coating could also be replaced by a stronger material, such as solder, she adds.

Hosoi is now investigating the use of other unconventional materials for robotics, such as magnetorheological and electrorheological fluids. These materials consist of a liquid with particles suspended inside, and can be made to switch from a soft to a rigid state with the application of a magnetic or electric field.

When it comes to artificial muscles for soft and biologically inspired robots, we tend to think of controlling shape through bending or contraction, says Carmel Majidi, an assistant professor of mechanical engineering in the Robotics Institute at Carnegie Mellon University, who was not involved in the research. “But for a lot of robotics tasks, reversibly tuning the mechanical rigidity of a joint can be just as important,” he says. “This work is a great demonstration of how thermally controlled rigidity-tuning could potentially be used in soft robotics.”

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

Thermally Tunable, Self-Healing Composites for Soft Robotic Applications by Nadia G. Cheng, Arvind Gopinath, Lifeng Wang, Karl Iagnemma, and Anette E. Hosoi. Macromolecular Materials and Engineering DOI: 10.1002/mame.201400017 Article first published online: 30 JUN 2014

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

This paper is behind a paywall.