Tag Archives: India

Functionalized nanomaterials for carbon capture

A few years ago I was at a breakfast hosted by a local member of the Canadian Parliament (Joyce Murray, Liberal, riding of Vancouver Quadra) and was unable to reply to a tablemate’s question about nanotechnology research in the area of carbon capture.  Since then I’ve stumbled across a few pieces of applicable research and hopefully someone will again ask me the question. In the meantime, some relevant recent work from India. From a May 9, 2016 news item on ScienceDaily,

Climate change due to excessive CO2 levels is one of the most serious problems humankind has ever faced. This has resulted in abrupt weather patterns such as flood and drought, which are extremely disruptive and detrimental to life, as we have been witnessing in India in recent years. Mitigating rising CO2 levels is of prime importance. In a new development, scientists at the Tata Institute of Fundamental Research, Mumbai, have developed a novel design of CO2 sorbents that show superior CO2 capture capacity and stability over conventional materials.

A May 9, 2016 Tata Institute of Fundamental Research press release on EurekAlert, which originated the news item, expands on the theme,

The immobilization of functional amines on a porous solid support can result in stable and efficient CO2 sorbent materials compared to similar liquid sorbents. A critical disadvantage however, is a drastic decrease in the textural properties of these supports (i.e., their surface area and pore volume), leading to a decrease in the CO2 capture capability.

To overcome this challenge, scientists at TIFR Mumbai, have designed novel functionalised nanomaterials that allows higher amine loading with a minimal decrease in surface area.

“Our fibrous nanosilica (KCC-1) should be a good candidate for use as a support to design efficient CO2 sorbents that would allow better capture capacity, kinetics and recylability”, says Dr Vivek Polshettiwar, the lead scientist of this study. A unique feature of KCC-1 is its high surface area, which originates from its fibrous morphology and not from its mesoporous channels (unlike in other well studied materials like SBA-15 or MCM-41). This study, published recently in the Journal of Materials Chemistry A, demonstrates the usefulness of the fibrous morphology of KCC-1 compared to conventional ordered mesoporous silica. This work is in continuation of the teams efforts to develop sustainable catalysts and sorbents.

The KCC-1-based sorbents showed several advantages over conventional silica-based sorbents, including i) high amine loading, ii) minimum reduction in surface area after functionalization and iii) more accessibility of the amine sites to enhance CO2 capture efficiency (i.e., capture capacity, kinetics and recyclability), due to the fibrous structure and high accessible surface area of KCC-1.

The demand for such efficient sorbents is on the rise since CO2 capture is one of the best solutions to mitigate the rising levels of CO2. Solid sorbents exhibit better efficiency with greater potential to overcome the shortcomings of liquid sorbents. The use of mesoporous silica materials functionalized with various amino groups is well reported. Although materials like SBA-15 and MCM-41, for example, have attracted significant attention because their large pore sizes can accommodate a variety of amine molecules and the high surface area allows for a higher loading of these functional molecules, they suffer from the disadvantages of a decrease in textural properties, thus making KCC-1 a suitable candidate for more efficient CO2 capture.

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

Design of CO2 sorbents using functionalized fibrous nanosilica (KCC-1): insights into the effect of the silica morphology (KCC-1 vs. MCM-41) by Baljeet Singh and Vivek Polshettiwar. J. Mater. Chem. A, 2016,4, 7005-7019 DOI: 10.1039/C6TA01348A First published online 08 Mar 2016

I believe this paper is behind a paywall.

Alberta’s Ingenuity Lab opens new facility in India and competes in the Carbon XPRIZE

India

The Ingenuity Lab in Alberta has made two recent announcements. The first one to catch my attention was a May 7, 2016 news item on Nanotechnology Now,

Ingenuity Lab is proud to announce the opening of the Ingenuity Lab Research Hub at Mahatma Gandhi University in Kottayam, Kerala India, to implement applied research and enable the translation of new 22nd century technologies. This new facility is the result of collaboration between the International and Inter University Centre for Nanoscience Nanotechnology (IIUCNN) and Ingenuity Lab to leverage what each participant does best.

Should the Nanotechnology Now news item not be available you can find the same information in a May 6, 2016 news item in The Canadian Business News Journal. Here’s the rest of the news item,

Ingenuity Lab, led by Dr. Carlo Montemagno, brings the best minds together to address global challenges and was in 2014 voted the Best Nanotechnology Research Organisation in 2014 by The New Economy. IIUCNN is led by Professor Sabu Thomas, whose vision it is to perform and coordinate academic and research activities in the frontier areas of Nanoscience and Nanotechnology by incorporating physical, chemical, biological and environmental aspects.

The two institutions are world-renowned for their work, and the new partnership should cover areas as diverse as catalysis, macromolecules, environmental chemistry, biological processes and health and wellness.

“The initial focus,” according to Ingenuity Lab’s Director Dr. Carlo Montemagno, “Will be on inexpensive point of care healthcare technologies and water availability for both agriculture and personal consumption.” However, in the future, he says, “We plan to expand the scope to include food safety and energy systems.”

Ingenuity Lab’s role is to focus on producing, adapting and supplying new materials to Ingenuity Lab India to focus on final device development and field-testing. The India team members know what system characteristics work best in developing economies, and will establish the figures of merit to make an appropriate solution. Alberta team members will then use this information to exercise its skills in advance materials and systems design to be crafted into its final form and field-tested.

The collaboration is somewhat unique in that it includes the bilateral exchange of students and researchers to facilitate the commercial translation of new and game changing technologies.

Dr. Babu Sebastian, Honourable Vice Chancellor of Mahatma Gandhi University, will declare the opening of the new facility in the presence of Dr. Montemagno, who will explain the vision of this research hub in association with his plenary lecture of ICM 2016.

Carbon XPRIZE

A May 9, 2016 press release on Market Wired describes Ingenuity Lab’s latest venture into carbon ‘transformation’,

Alberta-based Ingenuity Lab has entered the Carbon XPRIZE under the name of Ingenuity Carbon Solutions. With competition registration taking place in March, Ingenuity Carbon Solutions plans to launch its latest carbon transformation technology and win the backing it so deserves on the world stage.

Ingenuity Lab is working to develop a technology that transforms CO2 emissions and changes the conversation on carbon and its consequences for the environment. By developing nano particles that have the capability to sequester CO2 from facility gas flue emissions, the technology can metabolize emissions into marketable by-products.

The Carbon XPRIZE this year seeks to inspire solutions to the issue of climate change by incentivizing the development of new and emerging CO2 conversation technologies. Described recently in a WEF [World Economic Forum] survey as the biggest potential threat to the economy in 2016, climate change has been targeted as a priority issue, and the XPRIZE has done a great deal to provide answers to the climate question.

Renowned for its role in bringing new and radical thought leaders into the public domain, the XPRIZE Board of Trustees include Elon Musk, James Cameron and Arianna Huffington and the prize never fails to attract the world’s brightest minds.

This year’s Carbon XPRIZE challenges participants including Ingenuity Lab and its Ingenuity Carbon Solutions team to reimagine the climate question by accelerating the development of technologies to convert CO2 into valuable products. Ingenuity Carbon Solutions and others will compete in a three-round competition for a total prize purse of $20m, with the winnings going towards the technology’s continued development.

I hope to hear more good news soon. Alberta could certainly do with some of that as it copes with Fort McMurray’s monstrous wildfire (more here in a NASA/ Goddard Space Flight Center May 9, 2016 news release on EurekAlert).

For anyone interesting Alberta’s ‘nano’ Ingenuity Lab, more can be found here.

Nanoparticles for sustainable ways to grow crops

An April 29, 2016 news item on Nanowerk celebrates research into food production,

Scientists are working diligently to prepare for the expected increase in global population — and therefore an increased need for food production— in the coming decades. A team of engineers at Washington University in St. Louis has found a sustainable way to boost the growth of a protein-rich bean by improving the way it absorbs much-needed nutrients.

Ramesh Raliya, a research scientist, and Pratim Biswas, the Lucy & Stanley Lopata Professor and chair of the Department of Energy, Environmental & Chemical Engineering, both in the School of Engineering & Applied Science, discovered a way to reduce the use of fertilizer made from rock phosphorus and still see improvements in the growth of food crops by using zinc oxide nanoparticles.

The food under investigation is the mung bean,

Researchers at Washington University in St. Louis hope that nanoparticle technology can help reduce the need for fertilizer, creating a more sustainable way to grow crops such as mung beans. Courtesy: Washington University in St. Louis

Researchers at Washington University in St. Louis hope that nanoparticle technology can help reduce the need for fertilizer, creating a more sustainable way to grow crops such as mung beans. Courtesy: Washington University in St. Louis

An April 28, 2016 Washington University in St. Louis  news release (also on EurekAlert) by Beth Miller, which originated the news item, provides more detail,

The research was published April 7 [2016] in the Journal of Agricultural and Food Chemistry. Raliya said this is the first study to show how to mobilize native phosphorus in the soil using zinc oxide nanoparticles over the life cycle of the plant, from seed to harvest.

Food crops need phosphorus to grow, and farmers are using more and more phosphorus-based fertilizer as they increase crops to feed a growing world population. However, the plants can only use about 42 percent of the phosphorus applied to the soil, so the rest runs off into the water streams, where it grows algae that pollutes our water sources. In addition, nearly 82 percent of the world’s phosphorus is used as fertilizer, but it is a limited supply, Raliya says.

“If farmers use the same amount of phosphorus as they’re using now, the world’s supply will be depleted in about 80 years,” Raliya said. “Now is the time for the world to learn how to use phosphorus in a more sustainable manner.”

Raliya and his collaborators, including Jagadish Chandra Tarafdar at the Central Arid Zone Research Institute in Jodhpur, India, created zinc oxide nanoparticles from a fungus around the plant’s root that helps the plant mobilize and take up the nutrients in the soil. Zinc also is an essential nutrient for plants because it interacts with three enzymes that mobilize the complex form of phosphorus in the soil into a form that plants can absorb.

“Due to climate change, the daily temperature and rainfall amounts have changed,” Raliya said. “When they changed, the microflora in the soil are also changed, and once those are depleted, the soil phosphorus can’t mobilize the phosphorus, so the farmer applies more. Our goal is to increase the activity of the enzymes by several-fold, so we can mobilize the native phosphorus several-fold.”

When Raliya and the team applied the zinc nanoparticles to the leaves of the mung bean plant, it increased the uptake of the phosphorus by nearly 11 percent and the activity of the three enzymes by 84 percent to 108 percent. That leads to a lesser need to add phosphorus on the soil, Raliya said.

“When the enzyme activity increases, you don’t need to apply the external phosphorus, because it’s already in the soil, but not in an available form for the plant to uptake,” he said. “When we apply these nanoparticles, it mobilizes the complex form of phosphorus to an available form.”

The mung bean is a legume grown mainly in China, southeast Asia and India, where 60 percent of the population is vegetarian and relies on plant-based protein sources. The bean is adaptable to a variety of climate conditions and is very affordable for people to grow.

Raliya said 45 percent of the worldwide phosphorus use for agriculture takes place in India and China. Much of the phosphorus supply in developing countries is imported from the United States and Morocco-based rock phosphate mines.

“We hope that this method of using zinc oxide nanoparticles can be deployed in developing countries where farmers are using a lot of phosphorus,” Raliya said.

“These countries are dependent on the U.S. to export phosphorus to them, but in the future, the U.S. may have to help supply food, as well. If this crop can grow in a more sustainable manner, it will be helpful for everyone.”

“This is a broader effort under way at the nexus of food, energy and water,” Biswas said. “Nanoparticle technology enabled by aerosol science helps develop innovative solutions to address this global challenge problem that we face today.”

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

Enhancing the Mobilization of Native Phosphorus in the Mung Bean Rhizosphere Using ZnO Nanoparticles Synthesized by Soil Fungi by Ramesh Raliya, Jagadish Chandra Tarafdar, and Pratim Biswas. J. Agric. Food Chem., 2016, 64 (16), pp 3111–3118 DOI: 10.1021/acs.jafc.5b05224 Publication Date (Web): April 07, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Arbro Pharmaceuticals and its bioavailable curcumin

Curcumin (a constituent of the spice turmeric) is reputed to have health benefits and has been used in traditional medicine in Asia (notably India) for millenia. Recently scientists have been trying to render curcumin more effective which means increasing its bioavailability (my Nov. 7, 2014 posting features some of that research). According to an April 29, 2016 Arbro Pharmaceuticals press release, the goal of increased bioavailability has been reached and a product is now available commercially,

Arbro Pharmaceuticals has launched SNEC30, a patented highly bioavailable self-nanoemulsifying curcumin formulation in the dosage of 30mg.

Curcumin is the active ingredient of turmeric or haldi, which has been widely used in traditional medicine and home remedies in India for hundreds of years.

Clinical research conducted over the last 25 years has shown curcumin to be effective against various diseases like cancer, pain, inflammation, arthritis, ulcers, psoriasis, arteriosclerosis, diabetes and many more pro-inflammatory conditions.

Despite its effectiveness against so many medical conditions, scientists have come to believe that curcumin’s true potential has been limited by its poor bioavailability which is caused by the fact that it has poor solubility and extensive pre-systemic metabolism.

Arbro Pharmaceuticals partnered with Jamia Hamdard University to carry out research and develop a novel formulation, which can overcome curcumin’s poor bioavailability. The development project was jointly funded by Arbro and the Department of Science and Technology, Government of India under its DPRP (Drug and Pharmaceutical Research Programme) scheme.

SNEC30 is the outcome of this joint research and is based on a novel self-nanoemulsifying drug delivery systems (SNEDDS) for which patents have been filed and the US patent has been granted.

“There has been tremendous interest in the therapeutic potential of curcumin but its poor bioavailability was a limiting factor, our research group together with Arbro took the challenge and applied nanotechnology to overcome this limitation and achieve highest ever bioavailability for curcumin,” said Dr. Kanchan Kohli, Asst. Prof, Faculty of Pharmacy, Jamia Hamdard University, who is one of the main developers of the formulation.

Nanotechnology is the engineering of functional systems at the molecular scale (CRN – Centre for Responsible Nanotechnology). The name stems from the fact that the structures are in the nano-metre (10-9 mm) in range. In pharmaceutics, nano-formulations are used for targeted drug-delivery, particularly in cancer therapy. It also finds numerous other applications in medicine.

“Just 30mg of curcumin that is contained in one capsule of SNEC30 has shown higher blood levels than what can be achieved by consuming the curcumin content of 1kg of raw haldi or turmeric,” said Mr. Vijay Kumar Arora, Managing Director, Arbro Pharmaceuticals.

About Arbro Pharmaceuticals:

Arbro Pharmaceuticals is a 30-year-old research oriented company with its own research and development, testing and manufacturing facilities. Arbro has been manufacturing and exporting hundreds of formulations under its own brand name to more than 10 countries.

I am not endorsing this product but if you are interested the SNEC30 website is here. I believe Arbro Pharmaceuticals’ headquarters, the company which produces SNEC30, are located in India.

NASA (US National Aeronautics and Space Administration), one of the world’s largest hackathons, and women

Elizabeth Segran’s April 19, 2016 article for Fast Company profiles some work being done at NASA (US National Aeronautics and Space Administration) to encourage more women to participate in their hackathons (Note: A link has been removed),

For the past four years, NASA has hosted the Space Apps Challenge, one of the biggest hackathons on the planet. Last year, 14,264 people gathered in 133 locations for 48 to 72 hours to create apps using NASA’s data. A team in Lome, Togo, built a clean water mapping app; one in Bangalore, India, created a desktop planetarium; another in Pasadena, California, created a pocket assistant for astronauts. This year’s hackathon happens this upcoming weekend [April 22 – 24, 2016].

While NASA has been able to attract participants from all corners of the globe, it has consistently struggled to get women involved. NASA is working very hard to change this. “The attendance is generally 80% male,” says Beth Beck, NASA’s open innovation project manager, who runs the Space Apps Hackathon. “It’s more everyman than everywoman.”

There is a mention of a 2015 Canadian hackathon and an observation Beth Beck made at the time (from the Segran article),

Beck noticed that female participation in hackathons seemed to drop after the middle school years. At last year’s hackathon in Toronto, for instance, there were two sections: one for students and one for adults. Girls made up at least half of the student participants. “The middle school girls looked like honey bees, running around in little packs to learn about the technology,” she says. “But in the main hacking area, it was all guys. I wanted to know what happens that makes them lose their curiosity and enthusiasm.”

Beck’s further observations led to these conclusions,

It turns out that women are not significantly more interested in certain subjects than others. What they cared about most was being able to explore these topics in a space that felt friendly and supportive. “They are looking for signals that they will be in a safe space where they feel like they belong,” Beck says. Often, these signals are very straightforward: they seek out pictures of women on the event’s webpage and look for women’s names on the speaker panels and planning committees. …

Another interesting thing that Beck discovered is that women who are brave enough to attend these events want to go a day early to get the lay of the land and perhaps form a team in advance. They want to become more comfortable with the physical space where the hackathon will take place and learn as much as possible about the topics. “When the hackathon then becomes flooded with men, they feel ready for it,” she says.

While men described hacking as something that they did in their spare time, the research showed that many women often had many other family responsibilities and couldn’t just attend a hackathon for fun. And this wasn’t just true in developing countries, where girls were often tasked with childcare and chores, while boys could focus on science. In the U.S., events where there was childcare provided were much more highly attended by women than those that did not have that option. …

NASA’s hackathons are open to people with diverse skill sets—not just people who know code. Beck has found that men are more likely to participate because they are interested in space; they simply show up with ideas. Women, on the other hand, need to feel like they have the appropriate battery of skills to contribute. With this knowledge, Beck has found it helpful to make it clear that each team needs strong storytellers who can explain the value of the app. …

The folks at NASA are still working at implementing these ideas and Segran’s article describes the initiatives and includes this story (Note: A link has been removed),

Last year [2015], for instance, two female students in Cairo noticed that the hackathon has specifically called out to women and they wanted to host a local chapter of the hackathon. Their professor, however, told them that women could not host the event. The women reached out to NASA themselves and Beck wrote to them personally, saying that she highly encouraged them to create their own event. That Cairo event ended up being the largest Space Apps hackathon in the world, with 700 participants and a wait list of 300. …

Kudos to Beth Beck, NASA, and those two women in Cairo.

For anyone (male/female) interested in the 2016 hackathon, it’s being held this weekend (April 22 – 24, 2016), from the NASA Space Apps Challenge homepage,

For 48-72 hours across the world, problem solvers like you join us for NASA’s International Space Apps Challenge, one of the largest hackathons in the universe. Empowered by open data, you collaborate with strangers, colleagues, friends, and family to solve perplexing challenges in new and unexpected ways — from designing an interactive space glove to natural language processing to clean water mapping. Join us on our open data mission, and show us how you innovate.

Not Just For Coders

Beginners, students, experts, engineers, makers, artists, storytellers — Space Apps is for you! We welcome all passionate problem solvers to join our community of innovators. Citizens like you have already created thousands of open-source solutions together through code, data visualizations, hardware and design. How will you make your global impact?

It’s too late to become a host for the hackathon but you may be able to find a location for one somewhere near you on the hackathon website’s Locations page. There are three locations in Canada for the 2016 edition: Toronto (waitlist), Winnipeg (still open), and Waterloo (waitlist).

Minimalist DNA nanodevices perform bio-analytical chemistry inside live cells

A comparison of minimalist versus baroque architecture is one of the more startling elements in this March 24, 2016 news item on Nanowerk about a scientist working with DNA (deoxyribonucleic acid) nanodevices,

Some biochemistry laboratories fashion proteins into complex shapes, constructing the DNA nanotechnological equivalent of Baroque or Rococo architecture. Yamuna Krishnan, however, prefers structurally minimalist devices.

“Our lab’s philosophy is one of minimalist design,” said Krishnan, a professor of chemistry at the University of Chicago. “It borders on brutalist. Functional with zero bells and whistles. There are several labs that design DNA into wonderful shapes, but inside a living system, you need as little DNA as possible to get the job done.”

That job is to act as drug-delivery capsules or as biomedical diagnostic tools.

A March 24, 2016 University of Chicago news release by Steve Koppes, which originated the news item, provides some background information before launching into the latest news,

In 2011, Krishnan and her group, then at the National Centre for Biological Sciences in Bangalore, India, became the first to demonstrate the functioning of a DNA nanomachine inside a living organism. This nanomachine, called I-switch, measured subcellular pH with a high degree of accuracy. Since 2011, Krishnan and her team have developed a palette of pH sensors, each keyed to the pH of the target organelle.

Last summer, the team reported another achievement: the development of a DNA nanosensor that can measure the physiological concentration of chloride with a high degree of accuracy.

“Yamuna Krishnan is one of the leading practitioners of biologically oriented DNA nanotechnology,” said Nadrian Seeman, the father of the field and the Margaret and Herman Sokol Professor of Chemistry at New York University. “These types of intracellular sensors are unique to my knowledge, and represent a major advance for the field of DNA nanotechnology.”

Chloride sensor

Chloride is the single most abundant, soluble, negatively charged molecule in the body. And yet until the Krishnan group introduced its chloride sensor—called Clensor—there was no effective and practical way to measure intracellular stores of chloride.

“What is especially interesting about this sensor is that it is completely pH independent,” Seeman said, a significant departure from Krishnan’s previous scheme. “She spent a number of years developing pH sensors that work intra-cellularly and provide a fluorescent signal as a consequence of a shift in pH.”

The ability to record chloride concentrations is important for many reasons. Chloride plays an important role in neurobiology, for example. But calcium and sodium—both positively charged ions—tend to grab most of the neurobiological glory because of their role in neuron excitation.

“But if you want your neuron to fire again, you have to bring it back to its normal state. You have to stop it firing,” Krishnan said. This is called “neuronal inhibition,” which chloride does.

“It’s important in order to reset your neuron for a second round of firing, otherwise we would all be able to use our brains only once,” she said.

Under normal circumstances, the transport of chloride ions helps the body produce thin, freely flowing mucus. But a genetic defect results in a life-threatening disease: cystic fibrosis. Clensor’s capacity to measure and visualize protein activity of molecules like the one related to cystic fibrosis transmembrane could lead to high-throughput assays to screen for chemicals that would restore normal functioning of the chloride channel.

Nine diseases

“One could use this to look at chloride ion channel activity in a variety of diseases,” Krishnan said. “Humans have nine chloride ion channels, and the mutation of each of these channels results in nine different diseases.” Among them are osteopetrosis, deafness, muscular dystrophy and Best’s macular dystrophy.

The pH-sensing capabilities of the I-switch, meanwhile, are important because cells contain multiple organelles that maintain specific values of acidity. Cells need these different microenvironments to carry out specialized chemical reactions.

“Each subcellular organelle has a specific resting value of acidity, and that acidity is crucial to its function,” Krishnan said. “When the pH is not the value that it’s meant to be, it results in a range of different diseases.”

There are 70 rare diseases called lysosomal storage disorders, which are progressive and often fatal. Each one—including Batten disease, Niemann-Pick disease, Pompe disease and Tay-Sachs disease—represents a different way a lysosome can go bad. She likened a defective lysosome to a garbage bin that never gets emptied.

“The lysosome is basically responsible for chewing up all the garbage and making sure it’s either reused or got rid of. It’s the most acidic organelle in the cell.” And that acidity is crucial for the degradation process.

Although there are 70 lysosomal storage diseases, small molecule drugs are available for only a few of them. These existing treatments—enzyme-replacement therapies—are expensive and are only palliative treatments. One goal of Krishnan’s group is to demonstrate the utility of their pH sensors to discover new biological insights into these diseases. Developing small molecule drugs—which are structurally simpler and easier to manufacture than traditional biological drugs—could help significantly.

“If we can do this for one or two lysosomal diseases, there’ll be hope for the other 68,” Krishnan said.

Here are links to and citations for the 2015 and 2011 papers,

A pH-independent DNA nanodevice for quantifying chloride transport in organelles of living cells by Sonali Saha, Ved Prakash, Saheli Halder, Kasturi Chakraborty, & Yamuna Krishnan. Nature Nanotechnology 10, 645–651 (2015)  doi:10.1038/nnano.2015.130 Published online 22 June 2015

An autonomous DNA nanomachine maps spatiotemporal pH changes in a multicellular living organism by Sunaina Surana, Jaffar M. Bhat, Sandhya P. Koushika, & Yamuna Krishnan. Nature Communications 2, Article number: 340  doi:10.1038/ncomms1340 Published 07 June 2011

The 2015 paper is behind a paywall but the 2011 paper is open access.

Identifying performance problems in nanoresonators

Use of nanoelectromechanical systems (NEMS) can now be maximised due to a technique developed by researchers at the Commissariat a l’Energie Atomique (CEA) and the University of Grenoble-Alpes (France). From a March 7, 2016 news item on ScienceDaily,

A joint CEA / University of Grenoble-Alpes research team, together with their international partners, have developed a diagnostic technique capable of identifying performance problems in nanoresonators, a type of nanodetector used in research and industry. These nanoelectromechanical systems, or NEMS, have never been used to their maximum capabilities. The detection limits observed in practice have always been well below the theoretical limit and, until now, this difference has remained unexplained. Using a totally new approach, the researchers have now succeeded in evaluating and explaining this phenomenon. Their results, described in the February 29 [2016] issue of Nature Nanotechnology, should now make it possible to find ways of overcoming this performance shortfall.

A Feb. 29, 2016 CEA press release, which originated the news item, provides more detail about NEMS and about the new technique,

NEMS have many applications, including the measurement of mass or force. Like a tiny violin string, a nanoresonator vibrates at a precise resonant frequency. This frequency changes if gas molecules or biological particles settle on the nanoresonator surface. This change in frequency can then be used to detect or identify the substance, enabling a medical diagnosis, for example. The extremely small dimensions of these devices (less than one millionth of a meter) make the detectors highly sensitive.

However, this resolution is constrained by a detection limit. Background noise is present in addition to the wanted measurement signal. Researchers have always considered this background noise to be an intrinsic characteristic of these systems (see Figure 2 [not reproduced here]). Despite the noise levels being significantly greater than predicted by theory, the impossibility of understanding the underlying phenomena has, until now, led the research community to ignore them.

The CEA-Leti research team and their partners reviewed all the frequency stability measurements in the literature, and identified a difference of several orders of magnitude between the accepted theoretical limits and experimental measurements.

In addition to evaluating this shortfall, the researchers also developed a diagnostic technique that could be applied to each individual nanoresonator, using their own high-purity monocrystalline silicon resonators to investigate the problem.

The resonant frequency of a nanoresonator is determined by the geometry of the resonator and the type of material used in its manufacture. It is therefore theoretically fixed. By forcing the resonator to vibrate at defined frequencies close to the resonant frequency, the CEA-Leti researchers have been able to demonstrate a secondary effect that interferes with the resolution of the system and its detection limit in addition to the background noise. This effect causes slight variations in the resonant frequency. These fluctuations in the resonant frequency result from the extreme sensitivity of these systems. While capable of detecting tiny changes in mass and force, they are also very sensitive to minute variations in temperature and the movements of molecules on their surface. At the nano scale, these parameters cannot be ignored as they impose a significant limit on the performance of nanoresonators. For example, a tiny change in temperature can change the parameters of the device material, and hence its frequency. These variations can be rapid and random.

The experimental technique developed by the team makes it possible to evaluate the loss of resolution and to determine whether it is caused by the intrinsic limits of the system or by a secondary fluctuation that can therefore by corrected. A patent has been applied for covering this technique. The research team has also shown that none of the theoretical hypotheses so far advanced to explain these fluctuations in the resonant frequency can currently explain the observed level of variation.

The research team will therefore continue experimental work to explore the physical origin of these fluctuations, with the aim of achieving a significant improvement in the performance of nanoresonators.

The Swiss Federal Institute of Technology in Lausanne, the Indian Institute of Science in Bangalore, and the California Institute of Technology (USA) have also participated in this study. The authors have received funding from the Leti Carnot Institute (NEMS-MS project) and the European Union (ERC Consolidator Grant – Enlightened project).

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

Frequency fluctuations in silicon nanoresonators by Marc Sansa, Eric Sage, Elizabeth C. Bullard, Marc Gély, Thomas Alava, Eric Colinet, Akshay K. Naik, Luis Guillermo Villanueva, Laurent Duraffourg, Michael L. Roukes, Guillaume Jourdan & Sébastien Hentz. Nature Nanotechnology (2016) doi:10.1038/nnano.2016.19 Published online 29 February 2016

This paper is behind a paywall.

Indian researchers establish a multiplex number to identify efficiency of multilevel resistive switching devices

There’s a Feb. 1, 2016 Nanowerk Spotlight article by Dr. Abhay Sagade of Cambridge University (UK) about defining efficiency in memristive devices,

In a recent study, researchers at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, India, have defined a new figure-of-merit to identify the efficiency of resistive switching devices with multiple memory states. The research was carried out in collaboration with the Indian Institute of Technology Madras (IITM), Chennai, and financially supported by Department of Science and Technology, New Delhi.

The scientists identified the versatility of palladium oxide (PdO) as a novel resistive switching material for use in resistive memory devices. Due to the availability to switch multiple redox states in the PdO system, researchers have controlled it by applying different amplitudes of voltage pulses.

To date, many materials have shown multiple memory states but there have been no efforts to define the ability of the fabricated device to switch between all possible memory states.

In this present report, the authors have defined the efficacy in a term coined as “multiplex number (M)” to quantify the performance of a multiple memory switching device:

For the PdO MRS device with five memory states, the multiplex number is found to be 5.7, which translates to 70% efficiency in switching. This is the highest value of M observed in any multiple memory device.

As multilevel resistive switching devices are expected to have great significance in futuristic brain-like memory devices [neuromorphic engineering products], the definition of their efficiency will provide a boost to the field. The number M will assist researches as well as technologist in classifying and deciding the true merit of their memory devices.

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

Defining Switching Efficiency of Multilevel Resistive Memory with PdO as an Example by K. D. M. Rao, Abhay A. Sagade, Robin John, T. Pradeep and G. U. Kulkarni. Advanced Electronic Materials Volume 2, Issue 2, February 2016 DOI: 10.1002/aelm.201500286

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.

Cellulose-based nanogenerators to power biomedical implants?

This cellulose nanogenerator research comes from India. A Jan. 27, 2016 American Chemical Society (ACS) news release makes the announcement,

Implantable electronics that can deliver drugs, monitor vital signs and perform other health-related roles are on the horizon. But finding a way to power them remains a challenge. Now scientists have built a flexible nanogenerator out of cellulose, an abundant natural material, that could potentially harvest energy from the body — its heartbeats, blood flow and other almost imperceptible but constant movements. …

Efforts to convert the energy of motion — from footsteps, ocean waves, wind and other movement sources — are well underway. Many of these developing technologies are designed with the goal of powering everyday gadgets and even buildings. As such, they don’t need to bend and are often made with stiff materials. But to power biomedical devices inside the body, a flexible generator could provide more versatility. So Md. Mehebub Alam and Dipankar Mandal at Jadavpur University in India set out to design one.

The researchers turned to cellulose, the most abundant biopolymer on earth, and mixed it in a simple process with a kind of silicone called polydimethylsiloxane — the stuff of breast implants — and carbon nanotubes. Repeated pressing on the resulting nanogenerator lit up about two dozen LEDs instantly. It also charged capacitors that powered a portable LCD, a calculator and a wrist watch. And because cellulose is non-toxic, the researchers say the device could potentially be implanted in the body and harvest its internal stretches, vibrations and other movements [also known as, harvesting biomechanical motion].

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

Native Cellulose Microfiber-Based Hybrid Piezoelectric Generator for Mechanical Energy Harvesting Utility by
Md. Mehebub Alam and Dipankar Mandal. ACS Appl. Mater. Interfaces, 2016, 8 (3), pp 1555–1558 DOI: 10.1021/acsami.5b08168 Publication Date (Web): January 11, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

I did take a peek at the paper to see if I could determine whether or not they had used wood-derived cellulose and whether cellulose nanocrystals had been used. Based on the references cited for the paper, I think the answer to both questions is yes.

My latest piece on harvesting biomechanical motion is a June 24, 2014 post where I highlight a research project in Korea and another one in the UK and give links to previous posts on the topic.

Hexanal and preventing (or diminishing) fruit spoilage

More mangoes thanks to an Indian-Sri Lankan-Canadian nanotechnologyresearch project is a Feb. 9, 2015 posting where I highlighted (not for the first time) a three country research project utilizing hexanal in boxes for fruit (mango) storage,

I’ve been wondering what happened since I posted about this ‘mango’ project some years ago (my June 21, 2012 posting and my Nov. 1, 2012 posting) so, it’s nice to get an update from this Fresh Fruit Portal Feb. 4, 2015 posting,

Developed by Canadian, Indian and Sri Lankan researchers in a collaborative project funded by the International Development Research Centre (IDRC), the nanotech mango boxes are said to improve the fruit’s resilience and therefore boost quality over long shipping distances.

The project – which also includes the Tamil Nadu Agricultural University, India and the Industrial Technical Institute, Sri Lanka – has tested the use of the bio-compound hexanal, an artificially synthesized version of a natural substance produced by injured plants to reduce post-harvest losses.

In the Feb. 9, 2015 posting I was featuring the project again as it had received new funding,

  • Researchers from the University of Guelph, Canada, Tamil Nadu Agricultural University, India, and the Industrial Technical Institute, Sri Lanka, have shown that a natural compound known as hexanal delays the ripening of mangos. Using nanotechnology, the team will continue to develop hexanal-impregnated packaging and biowax coatings to improve the fruit’s resilience during handling and shipping for use in Asia, Africa, and the Caribbean. It will also expand its research to include other fruit and look at ways to commercialize the technologies.

New funding will allow the research teams to further develop the new technologies and involve partners who can bring them to market to reach greater numbers of small-holder farmers.

A Dec. 29, 2015 article (Life of temperate fruits in orchards extended, thanks to nanotech) in The Hindu newspaper provides an update on the collaboration,

Talking to mediapersons after taking part in a workshop on ‘Enhanced Preservation of Fruits using Nanotechnology Project’ held at the Horticultural College and Research Institute, Periyakulam near here on Monday [Dec. 28, 2015], he [K.S. Subramanian, Professor, Department of Nano Science and Technology, TNAU, Coimbatore] said countries like Sri Lanka, Tanzania, Kenya and West Indies will benefit. Post-harvest loss in African countries was approximately 80 per cent, whereas it was 25 to 30 per cent in India, he said.

With the funds sanctioned by Canadian Department of Foreign Affairs, Trade and Development and International Development Research Centre, Canada, the TN Agricultural University, Coimbatore, involving scientists in University of Guelph, Canada, Industrial Technology Institute, Colombo, Sokoine University of Agriculture, Tanzania, University of Nairobi [Kenya], University of West Indies, Trinidad and Tobago, have jointly developed Hexanal formulation, a nano-emulsion, to minimise post harvest loss and extend shelf life of mango.

Field trials have been carried out successfully in Dharmapuri and Krishnagiri on five varieties – Neelam, Bangalura, Banganapalle, Alphonso and Imam Pasand. Pre-harvest spray of Hexanal formulation retained fruits in the trees for three weeks and three more weeks in storage.

Extending life to six to eight weeks will benefit exporters immensely as they required at least six weeks to take fruits to European and the US market. Existing technologies were sufficient to retain fruits up to four weeks only. Domestic growers too can delay harvest and tap market when in demand.

In a companion Dec. 29, 2015 article (New technologies will enhance income of farmers) for The Hindu, benefits for the Indian agricultural economy were extolled,

Nano technology is an ideal tool to extend the shelf life and delay in ripening mango in trees, but proper bio-safety tests should be done before introducing it to farmers, according to Deputy Director General of ICAR N.K. Krishnakumar.

Inaugurating a workshop on Enhanced Preservation of Fruits using Nanotechnology Project held at the Horticultural College and Research Institute at Periyakulam near here on Monday [Dec. 28, 2015], he said that bio safety test was very important before implementing any nano-technology. Proper adoption of new technologies would certainly enhance the income of farmers, he added.

Demand for organic fruits was very high in foreign countries, he said, adding that Japan and Germany were prepared to buy large quantum of organic pomegranate. Covering fruits in bags would ensure uniform colour and quality, he said.

He appealed to scale down use of chemical pesticides and fertilizers to improve quality and taste. He said dipping mango in water mixed with salt will suffice to control fungus.

Postgraduate and research students should take up a problem faced by farmers and find a solution to it by working in his farm. His thesis could be accepted for offering degree only after getting feedback from that farmer. Such measure would benefit college, students and farmers, Mr. Krishnakumar added.

It’s good to get an update on the project’s progress and, while it’s not clear from the excerpts I have here, they are testing hexanal with on fruit other than mangoes.