Tag Archives: China

Killing mosquitos and other pests with genetics-based technology

Having supplied more than one tasty meal for mosquitos (or, as some prefer, mosquitoes), I am not their friend but couldn’t help but wonder about unintended consequences (as per Max Weber) on reading about a new patent awarded to Kansas State University (from a Nov. 12, 2014 news item on Nanowerk),

Kansas State University researchers have developed a patented method of keeping mosquitoes and other insect pests at bay.

U.S. Patent 8,841,272, “Double-Stranded RNA-Based Nanoparticles for Insect Gene Silencing,” was recently awarded to the Kansas State University Research Foundation, a nonprofit corporation responsible for managing technology transfer activities at the university. The patent covers microscopic, genetics-based technology that can help safely kill mosquitos and other insect pests.

A Nov. 12, 2014 Kansas State University news release, which originated the news item, provides more detail about the research,

Kun Yan Zhu, professor of entomology; Xin Zhang, research associate in the Division of Biology; and Jianzhen Zhang, visiting scientist from Shanxi University in China, developed the technology: nanoparticles comprised of a nontoxic, biodegradable polymer matrix and insect derived double-stranded ribonucleic acid, or dsRNA. Double-stranded RNA is a synthesized molecule that can trigger a biological process known as RNA interference, or RNAi, to destroy the genetic code of an insect in a specific DNA sequence.

The technology is expected to have great potential for safe and effective control of insect pests, Zhu said.

“For example, we can buy cockroach bait that contains a toxic substance to kill cockroaches. However, the bait could potentially harm whatever else ingests it,” Zhu said. “If we can incorporate dsRNA specifically targeting a cockroach gene in the bait rather than a toxic substance, the bait would not harm other organisms, such as pets, because the dsRNA is designed to specifically disable the function of the cockroach gene.”

Researchers developed the technology while looking at how to disable gene functions in mosquito larvae. After testing a series of unsuccessful genetic techniques, the team turned to a nanoparticle-based approach.

Once ingested, the nanoparticles act as a Trojan horse, releasing the loosely bound dsRNA into the insect gut. The dsRNA then triggers a genetic chain reaction that destroys specific messenger RNA, or mRNA, in the developing insects. Messenger RNA carries important genetic information.

In the studies on mosquito larvae, researchers designed dsRNA to target the mRNA encoding the enzymes that help mosquitoes produce chitin, the main component in the hard exoskeleton of insects, crustaceans and arachnids.

Researchers found that the developing mosquitoes produced less chitin. As a result, the mosquitoes were more prone to insecticides as they no longer had a sufficient amount of chitin for a normal functioning protective shell. If the production of chitin can be further reduced, the insects can be killed without using any toxic insecticides.

While mosquitos were the primary insect for which the nanoparticle-based method was developed, the technology can be applied to other insect pests, Zhu said.

“Our dsRNA molecules were designed based on specific gene sequences of the mosquito,” Zhu said. “You can design species-specific dsRNA for the same or different genes for other insect pests. When you make baits containing gene-specific nanoparticles, you may be able to kill the insects through the RNAi pathway. We see this having really broad applications for insect pest management.”

The patent is currently available to license through the Kansas State University Institute for Commercialization, which licenses the university’s intellectual property. The Institute for Commercialization can be contacted at 785-532-3900 and [email protected]

Eight U.S. patents have been awarded to the Kansas State University Research Foundation in 2014 for inventions by Kansas State University researchers.

Here’s an image of the ‘Trojan horse’ nanoparticles,

The nanoparticles, pictured as gold colored, are less than 100 nanometers in diameter. photo credit: bogdog Dan via photopincc

The nanoparticles, pictured as gold colored, are less than 100 nanometers in diameter. photo credit: bogdog Dan via photopincc

My guess is that the photographer has added some colour such as the gold and the pink to enhance the image as otherwise this would be a symphony of grey tones.

So, if this material will lead to weakened chitin such that pesticides and insecticides are more effective, does this mean that something else in the food chain will suffer because it no longer has mosquitos and other pests to munch on?

One last note, usually my ‘mosquito’ pieces concern malaria and the most recent of those was a Sept. 4, 2014 posting about a possible malaria vaccine being developed at the University of Connecticut.

Silver nanoparticles: liquid on the outside, crystal on the inside

Research from the Massachusetts Institute of Technology (MIT) has revealed a new property of metal nanoparticles, in this case, silver. From an Oct. 12, 2014 news item on ScienceDaily,

A surprising phenomenon has been found in metal nanoparticles: They appear, from the outside, to be liquid droplets, wobbling and readily changing shape, while their interiors retain a perfectly stable crystal configuration.

The research team behind the finding, led by MIT professor Ju Li, says the work could have important implications for the design of components in nanotechnology, such as metal contacts for molecular electronic circuits.

The results, published in the journal Nature Materials, come from a combination of laboratory analysis and computer modeling, by an international team that included researchers in China, Japan, and Pittsburgh, as well as at MIT.

An Oct. 12, 2014 MIT news release (also on EurekAlert), which originated the news item, offers both more information about the research and a surprising comparison of nanometers to the width of a human hair,

The experiments were conducted at room temperature, with particles of pure silver less than 10 nanometers across — less than one-thousandth of the width of a human hair. [emphasis mine] But the results should apply to many different metals, says Li, senior author of the paper and the BEA Professor of Nuclear Science and Engineering.

Silver has a relatively high melting point — 962 degrees Celsius, or 1763 degrees Fahrenheit — so observation of any liquidlike behavior in its nanoparticles was “quite unexpected,” Li says. Hints of the new phenomenon had been seen in earlier work with tin, which has a much lower melting point, he says.

The use of nanoparticles in applications ranging from electronics to pharmaceuticals is a lively area of research; generally, Li says, these researchers “want to form shapes, and they want these shapes to be stable, in many cases over a period of years.” So the discovery of these deformations reveals a potentially serious barrier to many such applications: For example, if gold or silver nanoligaments are used in electronic circuits, these deformations could quickly cause electrical connections to fail.

It was a bit surprising to see the reference to 10 nanometers as being less than 1/1,000th (one/one thousandth) of the width of a human hair in a news release from MIT. Generally, a nanometer has been described as being anywhere from less than 1/50,000th to 1/120,000th of the width of a human hair with less than 1/100,000th being one of the most common descriptions. While it’s true that 10 nanometers is less than 1/1,000th of the width of a human hair, it seems a bit misleading when it could be described, in keeping with the more common description, as less than 1/10,000th.

Getting back to the research, the news release offers more details as to how it was conducted,

The researchers’ detailed imaging with a transmission electron microscope and atomistic modeling revealed that while the exterior of the metal nanoparticles appears to move like a liquid, only the outermost layers — one or two atoms thick — actually move at any given time. As these outer layers of atoms move across the surface and redeposit elsewhere, they give the impression of much greater movement — but inside each particle, the atoms stay perfectly lined up, like bricks in a wall.

“The interior is crystalline, so the only mobile atoms are the first one or two monolayers,” Li says. “Everywhere except the first two layers is crystalline.”

By contrast, if the droplets were to melt to a liquid state, the orderliness of the crystal structure would be eliminated entirely — like a wall tumbling into a heap of bricks.

Technically, the particles’ deformation is pseudoelastic, meaning that the material returns to its original shape after the stresses are removed — like a squeezed rubber ball — as opposed to plasticity, as in a deformable lump of clay that retains a new shape.

The phenomenon of plasticity by interfacial diffusion was first proposed by Robert L. Coble, a professor of ceramic engineering at MIT, and is known as “Coble creep.” “What we saw is aptly called Coble pseudoelasticity,” Li says.

Now that the phenomenon has been understood, researchers working on nanocircuits or other nanodevices can quite easily compensate for it, Li says. If the nanoparticles are protected by even a vanishingly thin layer of oxide, the liquidlike behavior is almost completely eliminated, making stable circuits possible.

There are some benefits to this insight (from the news release),

On the other hand, for some applications this phenomenon might be useful: For example, in circuits where electrical contacts need to withstand rotational reconfiguration, particles designed to maximize this effect might prove useful, using noble metals or a reducing atmosphere, where the formation of an oxide layer is destabilized, Li says.

The new finding flies in the face of expectations — in part, because of a well-understood relationship, in most materials, in which mechanical strength increases as size is reduced.

“In general, the smaller the size, the higher the strength,” Li says, but “at very small sizes, a material component can get very much weaker. The transition from ‘smaller is stronger’ to ‘smaller is much weaker’ can be very sharp.”

That crossover, he says, takes place at about 10 nanometers at room temperature — a size that microchip manufacturers are approaching as circuits shrink. When this threshold is reached, Li says, it causes “a very precipitous drop” in a nanocomponent’s strength.

The findings could also help explain a number of anomalous results seen in other research on small particles, Li says.

For more details about the various attempts to create smaller computer chips, you can read my July 11, 2014 posting about IBM and its proposed 7 nanometer chip where you will also find links to announcements and posts about Intel’s smaller chips and HP Labs’ attempt to recreate computers.

As for the research into liquid-like metallic (silver) nanoparticles, here’s a link to and a citation for the paper,

Liquid-like pseudoelasticity of sub-10-nm crystalline ​silver particle by Jun Sun, Longbing He, Yu-Chieh Lo, Tao Xu, Hengchang Bi, Litao Sun, Ze Zhang, Scott X. Mao, & Ju Li. Nature Materials (2014) doi:10.1038/nmat4105 Published online 12 October 2014

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

Pushing molecular gastronomy boundaries to create new cooking techniques

Researchers are hoping to develop new cooking techniques eventually by looking closely at how chefs practice molecular gastronomy, From an Oct. 1, 2014 news item on phys.org,

One of the most iconic forms of avant-garde cuisine, also known as molecular gastronomy, involves the presentation of flavorful, edible liquids—like cocktails or olive oil—packaged into spheres. Now a team of scientists, in collaboration with world-renowned chef Ferran Adriá, is getting to the bottom of what makes these delectable morsels possible. Their findings appear in ACS’ The Journal of Physical Chemistry B.

For anyone who wants to see these edible liquids, there’s this demonstration by Ferran Adriá

An Oct. 1, 2014 American Chemical Society news release on EurekAlert, which originated the news item, provides a few more details about the research,

Christophe Chipot, Wensheng Cai and colleagues explain that the technique of “spherification” was invented 70 years ago but was popularized in avant-garde cuisine more recently by Adriá. The process of making the spheres involves packaging juice or other liquid ingredients in envelopes of calcium alginate, a gelatinous substance made mostly out of molecules extracted from brown seaweed. Although spherification has become a prominent technique in molecular gastronomy, no one had investigated the formation and stability of the alginates at the atomic level. Chipot’s team wanted to change that.

The researchers used classical molecular dynamics techniques to probe how alginate spheres form. Among other discoveries, they found that alginate chains spontaneously wrap like a net around liquid droplets and that calcium ions were key. They concluded that studies such as these, which bridge the gap between material science and avant-garde cuisine, could help chefs and food scientists rationally design the next generation of innovative cooking techniques.

The funds for this work came from a number of institutions (from the news release),

The authors acknowledge funding from the National Natural Science Foundation of China, the Natural Science Foundation of Tianjin, China and the Cai Yuanpei program of the  [France?] Ministère des Affaires Étrangères et du Développement International.

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

From Material Science to Avant-Garde Cuisine. The Art of Shaping Liquids into Spheres by Haohao Fu, Yingzhe Liu, Ferran Adrià, Xueguang Shao, Wensheng Cai, and Christophe Chipot. J. Phys. Chem. B, Article ASAP DOI: 10.1021/jp508841p Publication Date (Web): September 15, 2014

Copyright © 2014 American Chemical Society

The researchers have also made this image illustrating the transformation of a bowl of peas into a chemical mass and finally into a reconstructed, liquid pea available.

PeaMolecularGastronomy

More on Nanopolis in China’s Suzhou Industrial Park

As far as I can tell, the 2015 opening date for a new building is still in place but, in the meantime, publicists are working hard to remind everyone about China’s Nanopolis complex (mentioned here in a Jan. 20, 2014 posting, which includes an architectural rendering of the proposed new building).

For the latest information, there’s a Sept. 25  2014 news item on Nanowerk,

For several years now Suzhou Industrial Park (SIP) has been channeling money, resources and talent into supporting three new strategic industries: nano-technology, biotechnology and cloud computing.

In 2011 it started building a hub for nano-tech development and commercialization called Nanopolis that today is a thriving and diverse economic community where research institutes, academics and start-up companies can co-exist and where new technology can flourish.

Nanopolis benefits from the cross-pollination of ideas that come from both academia and business as it is right next door to the Suzhou Dushu Lake Science & Education Innovation District and its 25 world-class universities.

Earlier this year the University of California, Los Angles [sic] (UCLA) set up an Institute for Technology Advancement that is developing R&D platforms focusing on areas such as new energy technology and in particular nanotechnology. And Oxford University will soon join the growing list of world-class universities setting up centers for innovation there.

To develop a critical mass at Nanopolis SIP has offered incentive plans and provided incubators and shared laboratories, even including nano-safety testing and evaluation. It has also helped companies access venture capital and private equity and eventually go public through IPOs [initial public offerings {to raise money on stock exchanges}].

A Sept. 25, 2014 Suzhou Industrial Park news release (on Business Wire), which originated the news item, provides an interesting view of projects and ambitions for Nanopolis,

 To develop a critical mass at Nanopolis SIP has offered incentive plans and provided incubators and shared laboratories, even including nano-safety testing and evaluation. It has also helped companies access venture capital and private equity and eventually go public through IPOs.

Many companies in Nanopolis are already breaking new ground in the areas of micro and nano-manufacturing (nanofabrication, printed electronics and instruments and devices); energy and environment (batteries, power electronics, water treatment, air purification, clean tech); nano materials (nano particles, nano structure materials, functional nano materials, nano composite materials); and nano biotechnology (targeted drug delivery, nano diagnostics, nano medical devices and nano bio-materials).

Zhang Xijun, Nanopolis’ chief executive and president, says the high-tech hub goes beyond what typical incubators and accelerators provide their clients and he predicts that its importance will only grow over the next five years as demand for nano-technology applications continues to pick up speed.

“As more and more companies want upstream technology they are going to be looking more at nano-technology applications,” he says. “The regional and central government is taking this field very seriously–there is a lot of support.”

Nanopolis can also serve as a bridge for foreign companies in terms of China market entry. “Nanopolis has become like a gateway for companies to access the Chinese market, our research capabilities and Chinese talent,” he says.

Owen Huang, general manager of POLYNOVA, a nano-tech company that set up in SIP five years ago, counts Apple as one of its customers and has annual sales of US$4 million, says the excellent infrastructure, supply chain and international outlook in Nanopolis are part of its allure.

“This site works along the lines of foreign governments and there is no need to entertain local officials [as is often customary in other parts of China],” he says. “Everyone is treated the same according to international standards of business.”

Nanopolis also can serve as a kind of go-between for bilateral projects between businesses and governments in China and those from as far away as Finland, the Netherlands and the Czech Republic.

In November 2012, for example, China’s Ministry of Science and Technology and Finland’s Ministry of Employment and the Economy built the China-Finland Nano Innovation Centre to jointly develop cooperation in the research fields of micro-nanofabrication, functional materials and nano-biomedicine.

SIP is also raising the profile of nano-tech and its importance in Nanopolis by hosting international conferences and exhibitions. From Sept. 24-27 [2014] the industrial park is hosting the ChiNano conference, which will be attended by more than more 700 nano-tech specialists from over thirty countries.

Zhang emphasizes that collaboration between academia and industry is an essential aspect of innovation and commercialization and argues that Nanopolis’ appeal goes beyond professor-founded companies. “The companies are in a position to provide good internship programs for students and there are also joint professorship positions made possible,” he explains. “We can also optimize school courses so they are better linked to industry wherever possible.”

Nanopolis’ creators expect that their holistic approach to business development will attract more than 300 organizations and businesses and as many as 30,000 people to the site over the next five years.

Wang Yunjun, chief executive of Mesolight, is one of the success stories. Mesolight, a nano-tech company that specializes in semi-conductor nano-crystals or quantum dots used in flat panel TV screens, mobile phones and lighting devices, recently secured US$2 million in the first round of venture capital funding with the help of the industrial park’s connections in the industry.

Two years ago Wang moved to Nanopolis from Little Rock, Arkansas, where he had tried to get his company off the ground. He believes that returning to China and setting up his business in SIP was the best thing he could have done.

“The incubators in SIP are doing much more than the incubators in the United States,” he explains. “In the U.S. I was in an incubator but that just meant getting research space. Here I get a lot of resources. Most importantly, though, I was taught how to run a business.”

Albert Goldson, executive director of Indo-Brazillian Associates LLC, a New York-based global advisory firm and think tank, notes that while the immediate benefits of the industrial park are evident, there are even greater implications over the long-term, including the loss of talented Chinese who leave China to study or set up companies abroad.

“If one creates an architecturally compelling urban design along with a high-tech and innovative hub it will attract young Chinese talent for the long term both professionally and personally,” he says.

Jiang Weiming, executive chairman of the Dushu Lake Science & Education Innovation District concedes that SIP is not Silicon Valley and says that is why the industrial park is evaluating its own DNA and working out its own solutions.

“We have put in place a plan to train nanotech-specific talent and the same for biotech and cloud computing,” he says. “I think the collaboration between the education institutions and the enterprises is fairly impressive.”

Jiang points to faculty members who have taken positions as chief technical officers and vice general managers of science at commercial enterprises so that they have a better idea of what the company needs and how educational institutes can support them. And that in turn is helpful for their own research and teaching.

“The biggest task is to create a healthy ecosystem here,” he concludes.

So far, at least, the ecosystem in Nanopolis and across the rest of the industrial park appears to be thriving.

“The companies will find the right partners,” SIP’s chairman Barry Yang says confidently. “It’s not what the government is here for. What we want to do is provide a good platform and a good environment …Companies are the actors and we build the theaters.”

Between the news item and Business Wire, the news release is here in its entirety since these materials can disappear from the web. While Nanowerk does make its materials available for years but it can’t hurt to have another copy here.

The Nanopolis website can be found here. Note: the English language option is not  operational as of today, Sept. 26, 2014. The Chinano 2014 conference (Sept. 24 – 26) website is here (English language version available).

Referencing Indo-Brazillian Associates LLC, a New York-based global advisory firm and think tank, may have been an indirect reference to the group of countries known as the BRICS (Brazil, Russia, India, China, and South Africa) or, sometimes, as BRIC ((Brazil, Russia, India, and China). Either of these entities may be mentioned with regard to a shift global power.

Russians and Chinese get cozy and talk nano

The Moscow Times has a couple of interesting stories about China and Russia. The first one to catch my eye was this one about Rusnano (Russian Nanotechnologies Corporation) and its invitation to create a joint China-Russian nanotechnology investment fund. From a Sept. 9, 2014 Moscow Times news item,

Rusnano has invited Chinese partners to create a joint fund for investment in nanotechnology, Anatoly Chubais, head of the state technology enterprise, was quoted as saying Tuesday [Sept. 9, 2014] by Prime news agency.

Russia is interested in working with China on nanotechnology as Beijing already invests “gigantic” sums in that sphere, Chubais said.

Perhaps the most interesting piece of news was in the last paragraph of that news item,

Moscow is pivoting toward the east to soften the impact of Western sanctions imposed on Russia over its role in Ukraine. …

Another Sept. 9, 2014 Moscow Times news item expands on the theme of Moscow pivoting east,

Russia and China pledged on Tuesday [Sept. 9, 2014] to settle more bilateral trade in ruble and yuan and to enhance cooperation between banks, First Deputy Prime Minister Igor Shuvalov said, as Moscow seeks to cushion the effects of Western economic sanctions [as a consequence of the situation in the Ukraine].

Russia and China pledged on Tuesday to settle more bilateral trade in ruble and yuan and to enhance cooperation between banks, First Deputy Prime Minister Igor Shuvalov said, as Moscow seeks to cushion the effects of Western economic sanctions.

For China, curtailing [the] dollar’s influence fits well with its ambitions to increase the clout of the yuan and turn it into a global reserve currency one day. With 32 percent of its $4 trillion foreign exchange reserves invested in U.S. government debt, Beijing wants to curb investment risks in dollars.

….

China and Russia signed a $400 billion gas supply deal in May [2014], securing the world’s top energy user a major source of cleaner fuel and opening a new market for Moscow as it risks losing European clients over the Ukraine crisis.

This is an interesting turn of events given that China and Russia (specifically the entity known as Soviet Union) have not always had the friendliest of relations almost going to war in 1969 over territorial disputes (Wikipedia entries: Sino-Soviet border conflict and China-Russian Border).

In any event, China may have its own reasons for turning to Russia at this time. According to Jack Chang of Associated Press (Sept. 11, 2014 article on the American Broadcasting News website), there is a major military buildup taking place in Asia as the biggest defence budget in Japan’s history has been requested, Vietnam doubles military spending, and the Philippines assembles a larger naval presence. In addition, India and South Korea are also investing in their military forces. (I was at a breakfast meeting [scroll down for the speaker’s video] in Jan. 2014 about Canada’s trade relations with Asia when a table companion [who’d worked for the Canadian International Development Agency, knew the Asian region very well, and had visited recently] commented that many countries such as Laos and Cambodia were very tense about China’s resurgence and its plans for the region.)

One final tidbit, this comes at an interesting juncture in the US science enterprise. After many years of seeing funding rise, the US National Nanotechnology Initiative (NNI) saw its 2015 budget request shrink by $200M US from its 2014 budget allotment (first mentioned here in a March 31, 2014 posting).

Sometimes an invitation to create a joint investment fund isn’t just an invitation.

Wearable solar panels with perovskite

There was a bit of a flutter online in late July 2014 about solar cell research and perovskite, a material that could replace silicon therefore making solar cells more affordable, which hopefully would lead to greater adoption of the technology. Happily, the publishers of the study seem to have reissued their news release (h/t Aug. 11, 2014 news item on Nanwerk).

From the Wiley online press release Nr. 29/2014,

Textile solar cells are an ideal power source for small electronic devices incorporated into clothing. In the journal Angewandte Chemie, Chinese scientists have now introduced novel solar cells in the form of fibers that can be woven into a textile. The flexible, coaxial cells are based on a perovskite material and carbon nanotubes; they stand out due to their excellent energy conversion efficiency of 3.3 % and their low production cost.

The dilemma for solar cells: they are either inexpensive and inefficient, or they have a reasonable efficiency and are very expensive. One solution may come from solar cells made of perovskite materials, which are less expensive than silicon and do not require any expensive additives. Perovskites are materials with a special crystal structure that is like that of perovskite, a calcium titanate. These structures are often semiconductors and absorb light relatively efficiently. Most importantly, they can move electrons excited by light for long distances within the crystal lattice before they return to their energetic ground state and take up a solid position – a property that is very important in solar cells.

A team led by Hisheng Peng at Fudan University in Shanghai has now developed perovskite solar cells in the form of flexible fibers that can be woven into electronic textiles. Their production process is relatively simple and inexpensive because it uses a solution-based process to build up the layers.

The anode is a fine stainless steel wire coated with a compact n-semiconducting titanium dioxide layer. A layer of porous nanocrystalline titanium dioxide is deposited on top of this. This provides a large surface area for the subsequent deposition of the perovskite material CH3NH3PbI3. This is followed by a layer made of a special organic material. Finally a transparent layer of aligned carbon nanotubes is continuously wound over the whole thing to act as the cathode. The resulting fiber is so fine and flexible that it can be woven into textiles.

The perovskite layer absorbs light, that excites electrons and sets them free, causing a charge separation between the electrons and the formally positively charged “holes” The electrons enter the conducting band of the compact titanium dioxide layer and move to the anode. The “holes” are captured by the organic layer. The large surface area and the high electrical conductivity of the carbon nanotube cathode aid in the rapid conduction of the charges with high photoelectric currents. The fiber solar cell can attain an energy conversion efficiency of 3.3 %, exceeding that of all previous coaxial fiber solar cells made with either dyes or polymers.

Here’s an image used in the press release illustrating the new fiber,

[downloaded from http://www.wiley-vch.de/vch/journals/2002/press/201429press.pdf]

[downloaded from http://www.wiley-vch.de/vch/journals/2002/press/201429press.pdf]

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

Integrating Perovskite Solar Cells into a Flexible Fiber by Longbin Qiu, Jue Deng, Xin Lu, Zhibin Yang, and Prof. Huisheng Peng. Angewandte Chemie International Edition DOI: 10.1002/anie.201404973 Article first published online: 22 JUL 2014

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

This paper is behind a paywall.

I found a second item about perovskite and solar cells in a May 16, 2014 article by Vicki Marshall for Chemistry World which discussed some research in the UK (Note: Links have been removed),

A lead-free and non-toxic alternative to current perovskite solar-cell technology has been reported by researchers in the UK: tin halide perovskite solar cells. They are also cheaper to manufacture than the silicon solar cells currently dominating the market.

Nakita Noel, part of Henry Snaith’s research team at the University of Oxford, describes how perovskite materials have caused a bit of a whirlwind since they came out in 2009: ‘Everybody that’s working in the solar community is looking to beat silicon.’ Despite the high efficiency of conventional crystalline silicon solar cells (around 20%), high production and installation costs decrease their economic feasibility and widespread use.

The challenge to find a cheaper alternative led to the development of perovskite-based solar cells, as organic–inorganic metal trihalide perovskites have both abundant and cheap starting materials. However, the presence of lead in some semiconductors could create toxicology issues in the future. As Noel puts it ‘every conference you present at somebody is bound to put up their hand and ask “What about the lead – isn’t this toxic?”’

Brian Hardin, co-founder of PLANT PV, US, and an expert in new materials for photovoltaic cells, says the study ‘should be considered a seminal work on alternative perovskites and is extremely valuable to the field as they look to better understand how changes in chemistry affect solar cell performance and stability.’

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

Lead-free organic–inorganic tin halide perovskites for photovoltaic applications by Nakita K. Noel, Samuel D. Stranks, Antonio Abate, Christian Wehrenfennig, Simone Guarnera, Amir-Abbas Haghighirad, Aditya Sadhana, Giles E. Eperon, Sandeep K. Pathak, Michael B. Johnston, Annamaria Petrozza, Laura M. Herza, and Henry J. Snaith. Energy Environ. Sci., 2014, Advance Article DOI: 10.1039/C4EE01076K First published online 01 May 2014

This article was open access until June 27, 2014 but now it is behind a paywall.

I notice there’s no mention of lead in the materials describing the research paper from the Chinese scientists. Perhaps they were working with lead-free materials.

Metaphors in a brief overview of the nanomedicine scene circa August 2014

An Aug. 1, 2014 article by Guizhi Zhu (University of Florida), Lei Mei ((Hunan University; China), and Weihong Tan (University of Florida) for The Scientist provides an overview of the latest and greatest regarding nanomedicine while underscoring the persistence of certain medical metaphors. This overview features a prediction and a relatively benign (pun intended) metaphor,

Both the academic community and the pharmaceutical industry are making increasing investments of time and money in nanotherapeutics. Nearly 50 biomedical products incorporating nanoparticles are already on the market, and many more are moving through the pipeline, with dozens in Phase 2 or Phase 3 clinical trials. Drugmakers are well on their way to realizing the prediction of Christopher Guiffre, chief business officer at the Cambridge, Massachusetts–based nanotherapeutics company Cerulean Pharma, who last November forecast, “Five years from now every pharma will have a nano program.”

Technologies that enable improved cancer detection are constantly racing against the diseases they aim to diagnose, and when survival depends on early intervention, losing this race can be fatal. [emphasis mine] While detecting cancer biomarkers is the key to early diagnosis, the number of bona fide biomarkers that reliably reveal the presence of cancerous cells is low. To overcome this challenge, researchers are developing functional nanomaterials for more sensitive detection of intracellular metabolites, tumor cell–membrane proteins, and even cancer cells that are circulating in the bloodstream. (See “Fighting Cancer with Nanomedicine,” The Scientist, April 2014.)

So, the first metaphor ‘racing’ gives the reader a sense of urgency, the next ones, including “fighting cancer’, provoke a somewhat different state of mind,

Eye on the target

The prototype of targeted drug delivery can be traced back to the concept of a “magic bullet,” proposed by chemotherapy pioneer and 1908 Nobel laureate Paul Ehrlich. [emphasis mine] E[hrlich envisioned a drug that could selectively target a disease-causing organism or diseased cells, leaving healthy tissue unharmed. A century later, researchers are developing many types of nanoscale “magic bullets” that can specifically deliver drugs into target cells or tissues.

It would seem we might be in a state of war as you ‘fight cancer’ with your ‘eyes on the target’ as you ‘shoot magic bullets’ in time to celebrate the 100th anniversary of the start to World War I.

Kostas Kostarelos wrote a Nov. 29, 2013 posting for the Guardian Science Blogs where he (professor of nanomedicine at the University of Manchester and director of the university’s Nanomedicine Lab) discussed war metaphors in medicine and possible unintended consequences (Note: A link has been removed). Here’s his discussion about the metaphors,

Almost every night I have watched the news these past few months my senses have been assaulted by unpleasant, at times distressing, images of war: missiles, killings and chemical bombs in Syria, Kenya, the USA. I wake up the next morning, trying to forget what I watched the night before, and going to work with our researchers to develop the next potential high-tech cure for cancer, thinking: “does what we do matter at all … ?”

So I was intrigued by an article that will be published in one of the scientific journals in our field entitled: “Nanomedicine metaphors: from war to care”. The next lab meeting we had was very awkward, because I was constantly thinking that indeed a lot of the words we were using to communicate our science were directly imported from the language of war. Targeting, stealth nanoparticle, smart bomb, elimination, triggered release, cell death. I struggled to find alternative language.

… Hollywood analogies and simplistic interpretations about “good” and “bad” may be inaccurate, but they do seem appropriate and convincing.

I must say, however, that even in pathology, modern medicine increasingly considers the disease to be part of our body, often leading to successful treatment not by “eradication” and “elimination” but by holistic management of a chronic condition. The case of HIV therapeutics is perhaps the brightest example of such revisionist thinking, which has transformed the disease from a “death sentence” in the early years after its discovery to a nonlethal chronic infection today.

Kostarelos then contrasts the less warlike ‘modern medicine’ metaphors with nanomedicine,

In nanomedicine, which is the application of nanotechnologies and nanomaterials to design medical treatments, the war imagery is even more prevalent. Two of the most clinically successful and intensively studied technologies that operate at the nanoscale are “stealth” and “targeted” medicines. “Stealth” refers to a hydrophilic (water-loving) shield built around a molecule or nanoparticle, made from polymers, that minimises its recognition by the body’s defence mechanisms. “Targeting” refers to the specific binding of certain molecules (such as antibodies, peptides and others) to receptors (or other proteins) present only at the surface of diseased cells. The literature in nanomedicine is abundant with both “stealthing”, “targeting” and combinations thereof.

Kostarelos then asks this question,

The question I keep asking myself since I read the article about war metaphors in nanomedicine has been whether we are using terminology in a simplistic, single-minded manner that could stifle creative and out-of-the-box thinking.

Intriguing unintended consequences, yes?

Getting back to The Scientist article, which I found quite informative and interesting, its ‘war metaphors’ seem to extend even to some of the artwork accompanying the article,

[downloaded from http://www.the-scientist.com/?articles.view/articleNo/40598/title/Nanomedicine/]

[downloaded from http://www.the-scientist.com/?articles.view/articleNo/40598/title/Nanomedicine/]

Is that a capsule or a bullet? Regardless, this * article provides a good overview of the research.

* The word ‘a’ was removed on Aug. 8, 2014.

Things falling apart: both a Nigerian novel and research at the Massachusetts Intitute of Technology

First the Nigerian novel ‘Things Fall Apart‘ (from its Wikipedia entry; Note: Links have been removed),

Things Fall Apart is an English-language novel by Nigerian author Chinua Achebe published in 1958 by William Heinemann Ltd in the UK; in 1962, it was also the first work published in Heinemann’s African Writers Series. Things Fall Apart is seen as the archetypal modern African novel in English, one of the first to receive global critical acclaim. It is a staple book in schools throughout Africa and is widely read and studied in English-speaking countries around the world. The title of the novel comes from William Butler Yeats’ poem “The Second Coming”.[1]

For those unfamiliar with the Yeats poem, this is the relevant passage (from Wikipedia entry for The Second Coming),

Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.

The other ‘Things fall apart’ item, although it’s an investigation into ‘how things fall apart’, is mentioned in an Aug. 4, 2014 news item on Nanowerk,

Materials that are firmly bonded together with epoxy and other tough adhesives are ubiquitous in modern life — from crowns on teeth to modern composites used in construction. Yet it has proved remarkably difficult to study how these bonds fracture and fail, and how to make them more resistant to such failures.

Now researchers at MIT [Massachusetts Institute of Technology] have found a way to study these bonding failures directly, revealing the crucial role of moisture in setting the stage for failure. Their findings are published in the journal Proceedings of the National Academy of Science in a paper by MIT professors of civil and environmental engineering Oral Buyukozturk and Markus Buehler; research associate Kurt Broderick of MIT’s Microsystems Technology Laboratories; and doctoral student Denvid Lau, who has since joined the faculty at the City University of Hong Kong.

An Aug. 4, 2014 MIT news release written by David Chandler (also on EurekAlert), which originated the news item, provides an unexpectedly fascinating discussion of bonding, interfaces, and infrastructure,

“The bonding problem is a general problem that is encountered in many disciplines, especially in medicine and dentistry,” says Buyukozturk, whose research has focused on infrastructure, where such problems are also of great importance. “The interface between a base material and epoxy, for example, really controls the properties. If the interface is weak, you lose the entire system.”

“The composite may be made of a strong and durable material bonded to another strong and durable material,” Buyukozturk adds, “but where you bond them doesn’t necessarily have to be strong and durable.”

Besides dental implants and joint replacements, such bonding is also critical in construction materials such as fiber-reinforced polymers and reinforced concrete. But while such materials are widespread, understanding how they fail is not simple.

There are standard methods for testing the strength of materials and how they may fail structurally, but bonded surfaces are more difficult to model. “When we are concerned with deterioration of this interface when it is degraded by moisture, classical methods can’t handle that,” Buyukozturk says. “The way to approach it is to look at the molecular level.”

When such systems are exposed to moisture, “it initiates new molecules at the interface,” Buyukozturk says, “and that interferes with the bonding mechanism. How do you assess how weak the interface becomes when it is affected? We came up with an innovative method to assess the interface weakening as a result of exposure to environmental effects.”

The team used a combination of molecular simulations and laboratory tests in its assessment. The modeling was based on fundamental principles of molecular interactions, not on empirical data, Buyukozturk says.

In the laboratory tests, Buyukozturk and his colleagues controlled the residual stresses in a metal layer that was bonded and then forcibly removed. “We validated the method, and showed that moisture has a degrading effect,” he says.

The findings could lead to exploration of new ways to prevent moisture from reaching into the bonded layer, perhaps using better sealants. “Moisture is the No. 1 enemy,” Buyukozturk says.

“I think this is going to be an important step toward assessment of the bonding, and enable us to design more durable composites,” he adds. “It gives a quantitative knowledge of the interface” — for example, predicting that under specific conditions, a given bonded material will lose 30 percent of its strength.

Interface problems are universal, Buyukozturk says, occurring in many areas besides biomedicine and construction. “They occur in mechanical devices, in aircraft, electrical equipment, in the packaging of electronic components,” he says. “We feel this will have very broad applications.”

Bonded composite materials are beginning to be widely used in airplane manufacturing; often these composites are then bonded to traditional materials, like aluminum. “We have not had enough experience to prove the durability of these composite systems is going to be there after 20 years,” Buyukozturk says.

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

A robust nanoscale experimental quantification of fracture energy in a bilayer material system by Denvid Lau, Kurt Broderick, Markus J. Buehler, and Oral Büyüköztürk. PNAS, doi: 10.1073/pnas.1402893111 published August 5, 2014

This paper is behind a paywall.

Boron as a ‘buckyball’ or borospherene

First there was the borophene (like graphene but using boron rather than carbon) announcement from Brown University in my Jan. 28, 214 posting and now US (Brown University again) and Chinese researchers have developed a boron ‘buckyball’. Coincidentally, this announcement comes just after the 2014 World Cup final (July 13, 2014). Representations of buckyballs always resemble soccer balls. (Note: Germany won.)

From a July 14, 2014 news item on Azonano,

The discovery 30 years ago of soccer-ball-shaped carbon molecules called buckyballs helped to spur an explosion of nanotechnology research. Now, there appears to be a new ball on the pitch.

Researchers from Brown University, Shanxi University and Tsinghua University in China have shown that a cluster of 40 boron atoms forms a hollow molecular cage similar to a carbon buckyball. It’s the first experimental evidence that a boron cage structure—previously only a matter of speculation—does indeed exist.

“This is the first time that a boron cage has been observed experimentally,” said Lai-Sheng Wang, a professor of chemistry at Brown who led the team that made the discovery. “As a chemist, finding new molecules and structures is always exciting. The fact that boron has the capacity to form this kind of structure is very interesting.”

The researchers have provided an illustration of their borospherene,

The carbon buckyball has a boron cousin. A cluster for 40 boron atoms forms a hollow cage-like molecule. Courtesy Brown University

The carbon buckyball has a boron cousin. A cluster for 40 boron atoms forms a hollow cage-like molecule. Courtesy Brown University

A July 9, 2104 Brown University news release (also on EurekAlert), which originated the news item, describes the borosphene’s predecessor, the carbon buckyball, and provides more details about this new molecule,

Carbon buckyballs are made of 60 carbon atoms arranged in pentagons and hexagons to form a sphere — like a soccer ball. Their discovery in 1985 was soon followed by discoveries of other hollow carbon structures including carbon nanotubes. Another famous carbon nanomaterial — a one-atom-thick sheet called graphene — followed shortly after.

After buckyballs, scientists wondered if other elements might form these odd hollow structures. One candidate was boron, carbon’s neighbor on the periodic table. But because boron has one less electron than carbon, it can’t form the same 60-atom structure found in the buckyball. The missing electrons would cause the cluster to collapse on itself. If a boron cage existed, it would have to have a different number of atoms.

Wang and his research group have been studying boron chemistry for years. In a paper published earlier this year, Wang and his colleagues showed that clusters of 36 boron atoms form one-atom-thick disks, which might be stitched together to form an analog to graphene, dubbed borophene. Wang’s preliminary work suggested that there was also something special about boron clusters with 40 atoms. They seemed to be abnormally stable compared to other boron clusters.

Figuring out what that 40-atom cluster actually looks like required a combination of experimental work and modeling using high-powered supercomputers.

On the computer, Wang’s colleagues modeled over 10,000 possible arrangements of 40 boron atoms bonded to each other. The computer simulations estimate not only the shapes of the structures, but also estimate the electron binding energy for each structure — a measure of how tightly a molecule holds its electrons. The spectrum of binding energies serves as a unique fingerprint of each potential structure.

The next step is to test the actual binding energies of boron clusters in the lab to see if they match any of the theoretical structures generated by the computer. To do that, Wang and his colleagues used a technique called photoelectron spectroscopy.

Chunks of bulk boron are zapped with a laser to create vapor of boron atoms. A jet of helium then freezes the vapor into tiny clusters of atoms. The clusters of 40 atoms were isolated by weight then zapped with a second laser, which knocks an electron out of the cluster. The ejected electron flies down a long tube Wang calls his “electron racetrack.” The speed at which the electrons fly down the racetrack is used to determine the cluster’s electron binding energy spectrum — its structural fingerprint.

The experiments showed that 40-atom-clusters form two structures with distinct binding spectra. Those spectra turned out to be a dead-on match with the spectra for two structures generated by the computer models. One was a semi-flat molecule and the other was the buckyball-like spherical cage.

“The experimental sighting of a binding spectrum that matched our models was of paramount importance,” Wang said. “The experiment gives us these very specific signatures, and those signatures fit our models.”

The borospherene molecule isn’t quite as spherical as its carbon cousin. Rather than a series of five- and six-membered rings formed by carbon, borospherene consists of 48 triangles, four seven-sided rings and two six-membered rings. Several atoms stick out a bit from the others, making the surface of borospherene somewhat less smooth than a buckyball.

As for possible uses for borospherene, it’s a little too early to tell, Wang says. One possibility, he points out, could be hydrogen storage. Because of the electron deficiency of boron, borospherene would likely bond well with hydrogen. So tiny boron cages could serve as safe houses for hydrogen molecules.

But for now, Wang is enjoying the discovery.

“For us, just to be the first to have observed this, that’s a pretty big deal,” Wang said. “Of course if it turns out to be useful that would be great, but we don’t know yet. Hopefully this initial finding will stimulate further interest in boron clusters and new ideas to synthesize them in bulk quantities.”

The theoretical modeling was done with a group led by Prof. Si-Dian Li from Shanxi University and a group led by Prof. Jun Li from Tsinghua University. The work was supported by the U.S. National Science Foundation (CHE-1263745) and the National Natural Science Foundation of China.

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

Observation of an all-boron fullerene by Hua-Jin Zhai, Ya-Fan Zhao, Wei-Li Li, Qiang Chen, Hui Bai, Han-Shi Hu, Zachary A. Piazza, Wen-Juan Tian, Hai-Gang Lu, Yan-Bo Wu, Yue-Wen Mu, Guang-Feng Wei, Zhi-Pan Liu, Jun Li, Si-Dian Li, & Lai-Sheng Wang. Nature Chemistry (2014) doi:10.1038/nchem.1999 Published online 13 July 2014

This paper is behind a paywall.

Bringing the Nanoworld Together Workshop in Beijing, China, Sept. 24 – 25, 2014

The speakers currently confirmed for the ‘Bringing the Nanoworld Together Workshop organized by Oxford Instruments are from the UK, China, Canada, the US, and the Netherlands as per a July 2, 2014 news item on Nanowerk (Note: A link has been removed),

‘Bringing the Nanoworld Together’ is an event organised by Oxford Instruments to share the expertise of scientists in the field of Nanotechnology. It will be hosted at the IOS-CAS [Institute of Semiconductors-Chinese Academy of Sciences] Beijing.

Starting with half day plenary sessions on 2D materials with guest plenary speaker Dr Aravind Vijayaraghavan from the National Graphene Institute in Manchester, UK, and on Quantum Information Processing with guest plenary speaker Prof David Cory from the Institute for Quantum Computing, University of Waterloo, Canada, Oxford Instruments’ seminar at the IOP in Beijing from 24-25th September [2014] promises to discuss cutting edge nanotechnology solutions for multiple applications.

A July 1, 2014 Oxford Instruments press release, which originated the news item, describes the sessions and provides more details about the speakers,

Two parallel sessions will focus on thin film processing, & materials characterisation, surface science and cryogenic environments and a wide range of topics will be covered within each technical area. These sessions will include guest international and Chinese speakers from renowned research institutions, speakers from the host institute, and technical experts from Oxford Instruments. This will also present an excellent opportunity for networking between all participants.

Confirmed speakers include the following, but more will be announced soon:

Dr. Aravind Vijayaraghavan, National Graphene Institute, Manchester, UK
Prof David Cory, Institute for Quantum Computing, University of Waterloo, Canada
Prof Guoxing Miao, Institute for Quantum Computing, University of Waterloo, Canada
Prof. HE Ke, Tsinghua University, Institute of Physics, CAS, China
Dr. WANG Xiaodong, Institute of Semiconductors, CAS, China
Prof Erwin Kessels, Tue Eindhoven, Netherlands
Prof. ZENG Yi, Institute of Semiconductor, CAS, China
Prof Robert Klie, University of Illinois Chicago, USA
Prof. Xinran WANG, Nanjing University, China
Prof. Zhihai CHENG, National Centre for Nanoscience and Technology, China
Prof. Yeliang WANG, Institute of Physics, CAS, China

The thin film processing sessions will review latest etch and deposition technological advances, including: ALD, Magnetron Sputtering, ICP PECVD, Nanoscale Etch, MEMS, MBE and more.

Materials characterisation, Surface Science and Cryogenic Environment sessions will cover multiple topics and technologies including: Ultra high vacuum SPM, Cryo free low temperature solutions, XPS/ESCA, an introduction to atomic force microscopy (AFM) and applications such as nanomechanics, In-situ heating and tensile characterisation using EBSD, Measuring Layer thicknesses and compositions using EDS, Nanomanipulation and fabrication within the SEM / FIB.

The host of last year’s Nanotechnology Tools seminar in India, Prof. Rudra Pratap, Chairperson at the Centre for Nano Science and Engineering, Indian Institute of Science, IISC Bangalore commented, “This seminar has been extremely well organised with competent speakers covering a variety of processes and tools for nanofabrication. It is great to have practitioners of the art give talks and provide tips and solutions based on their experience, something that cannot be found in text books.”

“This workshop is a great opportunity for a wide range of scientists in research and manufacturing to discover practical aspects of many new and established processes, technologies and applications, directly from renowned scientists and a leading manufacturer with over 50 years in the industry”, comments Mark Sefton, Sector Head of Oxford Instruments NanoSolutions, “Delegates appreciate the informal workshop atmosphere of these events, encouraging delegates to participate through open discussion and sharing their questions and experiences.”

This seminar is free of charge but prior booking is essential.

You can register on the Oxford Instruments website’s Bringing the Nanoworld Together Workshop webpage,