Tag Archives: Singapore

Gold nanoparticles as catalysts for clear water and hydrogen production

The research was published online May 2014 and in a July 2014 print version,  which seems a long time ago now but there’s a renewed interest in attracting attention for this work. A Dec. 17, 2014 news item on phys.org describes this proposed water purification technology from Singapore’s A*STAR (Agency for Science Technology and Research), Note: Links have been removed,

A new catalyst could have dramatic environmental benefits if it can live up to its potential, suggests research from Singapore. A*STAR researchers have produced a catalyst with gold-nanoparticle antennas that can improve water quality in daylight and also generate hydrogen as a green energy source.

This water purification technology was developed by He-Kuan Luo, Andy Hor and colleagues from the A*STAR Institute of Materials Research and Engineering (IMRE). “Any innovative and benign technology that can remove or destroy organic pollutants from water under ambient conditions is highly welcome,” explains Hor, who is executive director of the IMRE and also affiliated with the National University of Singapore.

A Dec. 17, 2014 A*STAR research highlight, which originated the news item, describes the photocatalytic process the research team developed and tested,

Photocatalytic materials harness sunlight to create electrical charges, which provide the energy needed to drive chemical reactions in molecules attached to the catalyst’s surface. In addition to decomposing harmful molecules in water, photocatalysts are used to split water into its components of oxygen and hydrogen; hydrogen can then be employed as a green energy source.

Hor and his team set out to improve an existing catalyst. Oxygen-based compounds such as strontium titanate (SrTiO3) look promising, as they are robust and stable materials and are suitable for use in water. One of the team’s innovations was to enhance its catalytic activity by adding small quantities of the metal lanthanum, which provides additional usable electrical charges.

Catalysts also need to capture a sufficient amount of sunlight to catalyze chemical reactions. So to enable the photocatalyst to harvest more light, the scientists attached gold nanoparticles to the lanthanum-doped SrTiO3 microspheres (see image). These gold nanoparticles are enriched with electrons and hence act as antennas, concentrating light to accelerate the catalytic reaction.

The porous structure of the microspheres results in a large surface area, as it provides more binding space for organic molecules to dock to. A single gram of the material has a surface area of about 100 square meters. “The large surface area plays a critical role in achieving a good photocatalytic activity,” comments Luo.

To demonstrate the efficiency of these catalysts, the researchers studied how they decomposed the dye rhodamine B in water. Within four hours of exposure to visible light 92 per cent of the dye was gone, which is much faster than conventional catalysts that lack gold nanoparticles.

These microparticles can also be used for water splitting, says Luo. The team showed that the microparticles with gold nanoparticles performed better in water-splitting experiments than those without, further highlighting the versatility and effectiveness of these microspheres.

The researchers have provided an illustration of the process,

Improved photocatalyst microparticles containing gold nanoparticles can be used to purify water. © 2014 A*STAR Institute of Materials Research and Engineering

Improved photocatalyst microparticles containing gold nanoparticles can be used to purify water.
© 2014 A*STAR Institute of Materials Research and Engineering

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

Novel Au/La-SrTiO3 microspheres: Superimposed Effect of Gold Nanoparticles and Lanthanum Doping in Photocatalysis by Guannan Wang, Pei Wang, Dr. He-Kuan Luo, and Prof. T. S. Andy Hor. Chemistry – An Asian Journal Volume 9, Issue 7, pages 1854–1859, July 2014. Article first published online: 9 MAY 2014 DOI: 10.1002/asia.201402007

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

This article is behind a paywall.

Singaporeans’ perceptions of nanotechnology and consumer attitudes towards nanotechnologies in food production

This is the first time I’ve seen a study about nanotechnology perception and awareness from Asia. (As I’m sure this is not the first or the only such study, I lament my language skills once more. Since my primary search is for English language materials with my second language, French, as a very distant second, I am limited to translated materials.)

This piece of research comes from Singapore. From a Dec. 11, 2014 news item on the Asian Scientist magazine website,

A survey published in the Journal of Nanoparticle Research shows that while the Singaporean population is more familiar with nanotechnology than their Western counterparts in the US and Europe, they are also more wary of the risks involved.

Asia is expected to dominate the use and release of nanomaterials into the environment, largely due to the size of the population. Furthermore, the region in general—and Singapore in particular—has invested heavily in nanotechnology research, rapidly translating their findings into industrial and consumer products. However, there has been a lack of studies documenting public attitudes and acceptance of new technologies such as nanotechnology.

To address this gap of information, a team of researchers led by first author Dr. Saji George from the Nanyang Polytechnic (NYP) Center for Sustainable Nanotechnology conducted a survey of 1,080 Singaporeans above the age of 15. Their results revealed that approximately 80 percent had some understanding of nanotechnology.

A June 20, 2014 Nanyang Polytechnic media release provides additional details about the research,

In a recent public perception study conducted in Singapore with 1,000 respondents, researchers from Nanyang Polytechnic’s (NYP) Centre for Sustainable Nanotechnology (CSN) found that 80% of respondents were aware of nanotechnology, while only 40% of them were positive about its benefits. This was shared at the official launch of the CSN today. The event was graced by Mr Derek Ho, Director-General, Environmental Public Health Division, National Environment Agency (NEA).

The Centre is the first-of-its-kind among institutes of higher learning (IHLs) in Singapore. It is dedicated to studying the potential impact of novel engineered nanomaterials, and developing ways to ensure that nanotechnology applications are adopted in a sustainable manner for individuals and the environment. This makes the $1 million facility a key training facility for NYP’s students from the Schools of Chemical & Life Sciences, Engineering, and Health Sciences.

Perceptions influenced by exposure to prior information

The perception study conducted in collaboration with the United Kingdom’s Newcastle University, is part of a worldwide study. [emphasis mine] About 1,000 respondents were surveyed in Singapore. Among them, 80% had some level of familiarity with nanotechnology,  while only 40% of them were positive about its benefits. One of the strong determinants that influenced the perception of the public was their prior exposure to news on adverse effects of nanotechnology. This could be due to negative information on nanotechnology carried in the media. Often these are over interpretations of laboratory studies that tend to dampen public confidence in nanotechnology.

“Nanotechnology may be a double-edged sword in some applications. A large proportion of the population is already aware of it, and interestingly, 60% have actually come across negative information on nanotechnology. This points to the need for the Centre for Sustainable Nanotechnology to conduct its work robustly and effectively, to sharpen the benefits, and blunt the risks associated with nanotechnology. This will enable industries to better apply the relevant solutions, and for people to use products containing nanotechnology more confidently. Another impetus for the Centre is that through such studies, companies will learn what consumers are concerned about in specific types of products and how these concerns can be addressed during product design and manufacturing stages,” said Dr Joel Lee, Director of NYP’s School of Chemical & Life Sciences where the Centre is located.

The study also found variations in perception among different socio-demographic groups, and among applications of nanotechnology across different product ranges, for example food, baby products, medicine, clothing, cosmetics, water filters and electronics.

While this is a segue, there’s a very interesting tidbit about silver nanoparticles in this media release,

Smarter Antibacterial Nanotechnology

Since the CSN started operations in 2013, senior lecturers, Dr Saji George and Dr Hannah Gardner, from NYP’s Schools of Chemical & Life Sciences and Engineering, respectively, have studied the effectiveness of nano-silver in eliminating bacteria – which accounts for 30% of commercial nanotechnology – in applications currently available in the market. Nano-silver is largely used as an alternate anti-microbial solution in a range of industries, including clothing, baby products, personal care products and medicine.

Their research findings, now filed as a patent, uncovered that some drug resistant bacterial strains could also develop resistance to silver, contrary to the general notion that all bacterial strains will succumb to it. The duo then designed and developed a cost-effective method to generate cationic polymer coated silver nanoparticles. They observed that these nanoparticles could eliminate pathogenic bacteria regardless of their ability to resist antibiotics and silver.

Dr Lee added, “Nano-silver has captured the attention of industry and researchers. What we hope to achieve with the CSN is two-fold. We aim to be a resource for industries and even government regulatory agencies to tap on to better understand nanotechnology, its effects, and improve on its applications. These would also translate into real-world industry projects for our students and equip them to better serve the industry when they embark on their careers.”

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

Awareness on adverse effects of nanotechnology increases negative perception among public: survey study from Singapore by Saji George, Gulbanu Kaptan, Joel Lee, Lynn Frewer. Journal of Nanoparticle Research November 2014, 16:2751 Date: 22 Nov 2014

This paper is behind a paywall.

I did search for the “… worldwide study” regarding nanotechnology awareness and perceptions but found instead a recently published study on the topic of consumer attitudes towards nanotechnologies used in food production practices which features George and Frewer,

Consumer attitudes towards nanotechnologies applied to food production by L.J. Frewer, N. Gupta, S. George, A.R.H. Fischer, E.L. Giles, and D. Coles. Trends in Food Science & Technology, Volume 40, Issue 2, December 2014, Pages 211–225 (Special Issue: Nanotechnology in Foods: Science behind and future perspectives)

This article is behind a paywall.

Nanotechnology education, artificial muscles, and Estonian high schools?

The University of Tartu (Estonia) announced in a Sept. 29, 2014 press release an educational and entrepreneurial programme about nanotechnology/nanoscience for teachers and students,

Led by the University of Tartu, innovative Estonian schools participate in the Quantum Spin-Off project, which aims to bring youth in contact with nanotechnology, modern science and high-tech entrepreneurship. Pupils participating in the project will learn about seven topics of nanotechnology, including the creation of artificial muscles and the manipulation of nanoparticles.

Most people have little contact with nanoscience and nanotechnologies, although the exciting nano-world has always been around us. “Most Estonian teachers do not have the experience of introducing nanoscience required for understanding the nano-world or the necessary connections that would allow visiting the experts in nanoscience and enterprises using the technology,” said the leader of the Quantum Spin-Off project, UT Professor of Technology Education Margus Pedaste, describing the current situation of acquiring nanotechnology knowledge in Estonia.

Coordinator of the project, Project Manager at the Centre for Educational Technology Maarika Lukk adds that nanoscience is interesting and necessary, as it offers plenty of practical applications, for instance in medicine, education, military industry and space.

The press release goes on to describe the Quantum Spin-Off project and the proposed nanoscience programme in more detail,

To bring nanoscience closer to pupils, educational researchers of the University of Tartu decided to implement the European Union LLP Comenius project “Quantum Spin-Off – connecting schools with high-tech research and entrepreneurship”. The objective of the project is to build a kind of a bridge: at one end, pupils can familiarise themselves with modern science, and at the other, experience its application opportunities at high-tech enterprises. “We also wish to inspire these young people to choose a specialisation related to science and technology in the future,” added Lukk.

The pupils can choose between seven topics of nanotechnology: the creation of artificial muscles, microbiological fuel elements, manipulation of nanoparticles, nanoparticles and ionic liquids as oil additives, materials used in regenerative medicine, deposition and 3D-characterisation of atomically designed structures and a topic covered in English, “Artificial robotic fish with EAP elements”.

Learning is based on study modules in the field of nanotechnology. In addition, each team of pupils will read a scientific publication, selected for them by an expert of that particular field. In that way, pupils will develop an understanding of the field and of scientific texts. On the basis of the scientific publication, the pupils prepare their own research project and a business plan suitable for applying the results of the project.

In each field, experts of the University of Tartu will help to understand the topics. Participants will visit a nanotechnology research laboratory and enterprises using nanotechnologies.

The project lasts for two years and it is also implemented in Belgium, Switzerland and Greece.

You can find more information about the European Union’s Quantum Spin-Off Project on its website (from the homepage),

The Quantum Spinoff project will bring science teachers and their pupils in direct contact with research and entrepreneurship in the high-tech nano sector, with the goal of educating a new generation of scientifically literate European citizens and inspiring young people to choose for science and technology careers. Teams of pupils, guided by their science teachers, will be challenged to create a responsible and socially relevant valorisation of a scientific paper in collaboration with actual researchers and entrepreneurs. They will visit high-tech research labs and will compete for the European Quantum Spin-Off Prize. Scientific and technological insights, creativity and responsible entrepreneurship will be all taken into account by the jury of experts. Science teachers will be trained in international and national workshops to support the inquiry learning process of their pupils.

This drive toward linking science to entrepreneurial output is an international effort as this Quantum-Spin Off project , Singapore’s A*STAR (Agency for Science, Technology and Research) and my Sept. 30, 2014 post about the 2014 Canadian Science Policy Conference  make abundantly clear.

Canada’s Situating Science in Fall 2014

Canada’s Situating Science cluster (network of humanities and social science researchers focused on the study of science) has a number of projects mentioned and in its Fall 2014 newsletter,

1. Breaking News
It’s been yet another exciting spring and summer with new developments for the Situating Science SSHRC Strategic Knowledge Cluster team and HPS/STS [History of Philosophy of Science/Science and Technology Studies] research. And we’ve got even more good news coming down the pipeline soon…. For now, here’s the latest.

1.1. New 3 yr. Cosmopolitanism Partnership with India and Southeast Asia
We are excited to announce that the Situating Science project has helped to launch a new 3 yr. 200,000$ SSHRC Partnership Development Grant on ‘Cosmopolitanism and the Local in Science and Nature’ with institutions and scholars in Canada, India and Singapore. Built upon relations that the Cluster has helped establish over the past few years, the project will closely examine the actual types of negotiations that go into the making of science and its culture within an increasingly globalized landscape. A recent workshop on Globalizing History and Philosophy of Science at the Asia Research Institute at the National University of Singapore helped to mark the soft launch of the project (see more in this newsletter).

ARI along with Manipal University, Jawaharlal Nehru University, University of King’s College, Dalhousie University, York University, University of Toronto, and University of Alberta, form the partnership from which the team will seek new connections and longer term collaborations. The project’s website will feature a research database, bibliography, syllabi, and event information for the project’s workshops, lecture series, summer schools, and artifact work. When possible, photos, blogs, podcasts and videos from events will be posted online as well. The project will have its own mailing list so be sure to subscribe to that too. Check it all out: www.CosmoLocal.org

2.1. Globalizing History and Philosophy of Science workshop in Singapore August 21-22 2014
On August 21 and 22, scholars from across the globe gathered at the Asia Research Institute at the National University of Singapore to explore key issues in global histories and philosophies of the sciences. The setting next to the iconic Singapore Botanical Gardens provided a welcome atmosphere to examine how and why globalizing the humanities and social studies of science generates intellectual and conceptual tensions that require us to revisit, and possibly rethink, the leading notions that have hitherto informed the history, philosophy and sociology of science.

The keynote by Sanjay Subrahmanyam (UCLA) helped to situate discussions within a larger issue of paradigms of civilization. Workshop papers explored commensurability, translation, models of knowledge exchange, indigenous epistemologies, commercial geography, translation of math and astronomy, transmission and exchange, race, and data. Organizer Arun Bala and participants will seek out possibilities for publishing the proceedings. The event partnered with La Trobe University and Situating Science, and it helped to launch a new 3 yr. Cosmopolitanism project. For more information visit: www.CosmoLocal.org

2.2. Happy Campers: The Summer School Experience

We couldn’t help but feel like we were little kids going to summer camp while our big yellow school bus kicked up dust driving down a dirt road on a hot summer’s day. In this case it would have been a geeky science camp. We were about to dive right into day-long discussions of key pieces from Science and Technology Studies and History and Philosophy of Science and Technology.

Over four and a half days at one of the Queen’s University Biology Stations at the picturesque Elbow Lake Environmental Education Centre, 18 students from across Canada explored the four themes of the Cluster. Each day targeted a Cluster theme, which was introduced by organizer Sergio Sismondo (Sociology and Philosophy, Queen’s). Daryn Lehoux (Classics, Queen’s) explained key concepts in Historical Epistemology and Ontology. Using references of the anti-magnetic properties of garlic (or garlic’s antipathy with the loadstone) from the ancient period, Lehoux discussed the importance and significance of situating the meaning of a thing within specific epistemological contexts. Kelly Bronson (STS, St. Thomas University) explored modes of science communication and the development of the Public Engagement with Science and Technology model from the deficit model of Public Understanding of Science and Technology during sessions on Science Communication and its Publics. Nicole Nelson (University of Wisconsin-Madison) explained Material Culture and Scientific/Technological Practices by dissecting the meaning of animal bodies and other objects as scientific artifacts. Gordon McOuat wrapped up the last day by examining the nuances of the circulation and translation of knowledge and ‘trading zones’ during discussions of Geographies and Sites of Knowledge.

2.3. Doing Science in and on the Oceans
From June 14 to June 17, U. King’s College hosted an international workshop on the place and practice of oceanography in celebration of the work of Dr. Eric Mills, Dalhousie Professor Emeritus in Oceanography and co-creator of the History of Science and Technology program. Leading ocean scientists, historians and museum professionals came from the States, Europe and across Canada for “Place and Practice: Doing Science in and on the Ocean 1800-2012”. The event successfully connected different generations of scholars, explored methodologies of material culture analysis and incorporated them into mainstream historical work. There were presentations and discussions of 12 papers, an interdisciplinary panel discussion with keynote lecture by Dr. Mills, and a presentation at the Maritime Museum of the Atlantic by Canada Science and Technology Museum curator, David Pantalony. Paper topics ranged from exploring the evolving methodology of oceanographic practice to discussing ways that the boundaries of traditional scientific writing have been transcended. The event was partially organized and supported by the Atlantic Node and primary support was awarded by the SSHRC Connection Grant.

2.4. Evidence Dead or Alive: The Lives of Evidence National Lecture Series

The 2014 national lecture series on The Lives of Evidence wrapped up on a high note with an interdisciplinary panel discussion of Dr. Stathis Psillos’ exploration of the “Death of Evidence” controversy and the underlying philosophy of scientific evidence. The Canada Research Chair in Philosophy of Science spoke at the University of Toronto with panelists from law, philosophy and HPS. “Evidence: Wanted Dead of Alive” followed on the heels of his talk at the Institute for Science, Society and Policy “From the ‘Bankruptcy of Science’ to the ‘Death of Evidence’: Science and its Value”.

In 6 parts, The Lives of Evidence series examined the cultural, ethical, political, and scientific role of evidence in our world. The series formed as response to the recent warnings about the “Death of Evidence” and “War on Science” to explore what was meant by “evidence”, how it is interpreted, represented and communicated, how trust is created in research, what the relationship is between research, funding and policy and between evidence, explanations and expertise. It attracted collaborations from such groups as Evidence for Democracy, the University of Toronto Evidence Working Group, Canadian Centre for Ethics in Public Affairs, Dalhousie University Health Law Institute, Rotman Institute of Philosophy and many more.

A December [2013] symposium, “Hype in Science”, marked the soft launch of the series. In the all-day public event in Halifax, leading scientists, publishers and historians and philosophers of science discussed several case studies of how science is misrepresented and over-hyped in top science journals. Organized by the recent winner of the Gerhard Herzberg Canada Gold Medal for Science and Engineering, Ford Doolittle, the interdisciplinary talks in “Hype” explored issues of trustworthiness in science publications, scientific authority, science communication, and the place of research in the broader public.

The series then continued to explore issues from the creation of the HIV-Crystal Meth connection (Cindy Patton, SFU), Psychiatric Research Abuse (Carl Elliott, U. Minnesota), Evidence, Accountability and the Future of Canadian Science (Scott Findlay, Evidence for Democracy), Patents and Commercialized Medicine (Jim Brown, UofT), and Clinical Trials (Joel Lexchin, York).

All 6 parts are available to view on the Situating Science YouTube channel.You can read a few blogs from the events on our website too. Some of those involved are currently discussing possibilities of following up on some of the series’ issues.

2.5. Other Past Activities and Events
The Frankfurt School: The Critique of Capitalist Culture (July, UBC)

De l’exclusion à l’innovation théorique: le cas de l’éconophysique ; Prosocial attitudes and patterns of academic entrepreneurship (April, UQAM)

Critical Itineraries Technoscience Salon – Ontologies (April, UofT)

Technologies of Trauma: Assessing Wounds and Joining Bones in Late Imperial China (April, UBC)

For more, check out: www.SituSci.ca

You can find some of the upcoming talks and the complete Fall 2014 Situating Science newsletter here.

About one week after receiving the newsletter, I got this notice (Sept. 11, 2014),

We are ecstatic to announce that the Situating Science SSHRC Strategic Knowledge Cluster is shortlisted for a highly competitive SSHRC Partnership Impact Award!

And what an impact we’ve had over the past seven years: Organizing and supporting over 20 conferences and workshops, 4 national lecture series, 6 summer schools, and dozens of other events. Facilitating the development of 4 new programs of study at partner institutions. Leveraging more than one million dollars from Nodal partner universities plus more than one million dollars from over 200 supporting and partnering organizations. Hiring over 30 students and 9 postdoctoral fellows. Over 60 videos and podcasts as well as dozens of student blogs and over 50 publications. Launching a new Partnership Development Grant between Canada, India and Southeast Asia. Developing a national consortium…And more!

The winners will be presented with their awards at a ceremony in Ottawa on Monday, November 3, 2014.

From the Sept. 11, 2014 Situating Science press release:

University of King’s College [Nova Scotia, Canada] professor Dr. Gordon McOuat has been named one of three finalists for the Social Sciences and Humanities Research Council of Canada’s (SSHRC) Partnership Award, one of five Impact Awards annually awarded by SSHRC.

Congratulations on the nomination and I wish Gordon McQuat and Situating Science good luck in the competition.

A rose by any other name: water pinning nanostructures and wettability

There are two items about rose petals as bioinspiration for research in this posting. The first being the most recent research where scientists in Singapore have made an ultrathin film modeled on rose petals. From an Aug. 13, 2014 news item on Nanowerk (Note: A link has been removed),

A*STAR [based in Singapore] researchers have used nanoimprinting methods to make patterned polymeric films with surface topography inspired by that of a rose petal, producing a range of transparent films with high water pinning forces (“Bioinspired Ultrahigh Water Pinning Nanostructures”).

An Aug. 13, 2014 A*STAR news highlight, which originated the news item, describes the nature of the research,

A surface to which a water droplet adheres, even when it is turned upside down, is described as having strong water pinning characteristics. A rose petal and a lotus leaf are both superhydrophobic, yet dissimilarities in their water pinning properties cause a water droplet to stick to a rose petal but roll off a lotus leaf. The two leaf types differ in their micro- and nanoscale surface topography and it is these topographical details that alter the water pinning force. The rose petal has almost uniformly distributed, conical-shaped microscale protrusions with nanoscale folds on these protrusions, while the lotus leaf has randomly distributed microscale protrusions.

The imprinted surfaces developed by Jaslyn Law and colleagues at the A*STAR Institute of Materials Research and Engineering and the Singapore University of Technology and Design have uniformly distributed patterns of nanoscale protrusions that are either conical or parabolic in shape. The researchers found that the water pinning forces on these continuously patterned surfaces were much greater than on non-patterned surfaces and surfaces composed of isolated nanopillared structures or nanoscale gratings. They could then achieve high water pinning forces by patterning the nanoprotrusions onto polymeric films with a range of different non-patterned hydrophobicities, including polycarbonate, poly(methyl methacrylate) and polydimethylsiloxane (see image).

“Other methods that recreate the water pinning effect have used actual rose petals as the mold, but unless special care is taken, there are likely to be defects and inconsistencies in the recreated pattern,” says co-author Andrew Ng. “While bottom-up approaches for making patterns — for example, laser ablation, liquid flame spray or chemical vapor deposition — are more consistent, these methods are limited in the types of patterns that can be used and the scale at which a substrate can be patterned.”

In contrast, nanoimprinting methods are capable of fabricating versatile and large-scale surfaces, and can be combined with roll-to-roll techniques, hence potentially enabling more commercial applications.

The patterned polycarbonate surfaces were also shown to reduce the ‘coffee-ring’ effect: the unevenly deposited film left behind upon the evaporation of a solute-laden droplet. This mitigation of the coffee-ring effect may assist microfluidic technologies and, more generally, the patterned surfaces could be used in arid regions for dew collection or in anti-drip applications such as in greenhouses.

The study which was published online in Dec. 2013, was featured in a Jan. 22, 2014 article by Katherine Bourzac for C&EN (Chemistry and Engineering News),

In the early morning, dew clings to rose petals; when the sun rises, the dewdrops act like tiny lenses, making diffraction patterns that attract pollinating insects, says Jaslyn Bee Khuan Law, a materials scientist at the Agency for Science, Technology, and Research (A*STAR), in Singapore. A drop of water will cling to a rose petal even when it’s tilted or held upside down. The petals can hold onto these droplets because their surfaces consist of closely packed conical structures a few micrometers across. These microscale surface patterns tweak the surface tension of the water droplets, causing them to cling to the petals.

But none of these fabrication methods are amenable to large-scale, low-cost manufacturing, preventing commercialization of the water-clinging surfaces. So Law turned to a specialty of her lab: nanoimprint lithography. This printing method utilizes metal or silicon drums molded with nanoscale features on their surfaces. When the molds are heated and pressed against sheets of plastic, the plastic is embossed with the nanoscale pattern. This roll-to-roll printing process resembles the way newspapers are printed. It’s capable of producing large-area films in a short amount of time.

Water droplets easily slid off plastic films patterned with simple nanoscale gratings; isolated nanoscale pillars hung onto water slightly better. But the films with the best properties consisted of tightly packed cones about 300 nm tall. Plastic patterned with these structures could hold onto water droplets as massive as 69 mg. The team could print a 110- by 65-mm sheet of this plastic film at a speed of 10 m per minute. Currently, the dimensions of the films are limited by the size of the premade molds, Law says.

While the Singapore group has made good progress on manufacturing these materials, very basic, vexing questions about how water clings to these surfaces remain, Hayes says. For example, very small changes in the surface’s roughness can switch it from water-pinning to super hydrophobic, and researchers don’t have a detailed understanding of why.

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

Bioinspired Ultrahigh Water Pinning Nanostructures by Jaslyn Bee Khuan Law, Andrew Ming Hua Ng, Ai Yu He, and Hong Yee Low. Langmuir, 2014, 30 (1), pp 325–331 DOI: 10.1021/la4034996 Publication Date (Web): December 20, 2013
Copyright © 2013 American Chemical Society

This paper appears to be open access (I was able to access it by clicking on the HTML option).

Finally, here’s an image supplied by the A*Star researchers to illustrate their work,

[downloaded from http://pubs.acs.org/doi/full/10.1021/la4034996]

[downloaded from http://pubs.acs.org/doi/full/10.1021/la4034996]

This second rose petal item comes from Australia and dates from Fall 2013. From a Sept. 18, 2013 news item on ScienceDaily,

A new nanostructured material with applications that could include reducing condensation in airplane cabins and enabling certain medical tests without the need for high tech laboratories has been developed by researchers at the University of Sydney [Australia].

“The newly discovered material uses raspberry particles — so-called because of their appearance — which can trap tiny water droplets and prevent them from rolling off surfaces, even when that surface is turned upside down,” said Dr Andrew Telford from the University’s School of Chemistry and lead author of the research recently published in the journal, Chemistry of Materials.

The ability to immobilise [pin] very small droplets on a surface is, according to Dr Telford, a significant achievement with innumerable potential applications.

A Sept. 17, 2013 University of Sydney news release, which originated the news item, provides more insight into the research where the scientists have focused on ‘raspberry particles’ which could also be described as the ‘conical structures’ mentioned in the A*STAR work to achieve what appear to be similar ends,

Raspberry particles mimic the surface structure of some rose petals.

“Water droplets bead up in a spherical shape on top of rose petals,” Dr Telford said. “This is a sign the flower is highly water repellent.”

The reasons for this are complex and largely due to the special structure of the rose petal’s surface. The research team replicated the rose petal by assembling raspberry particles in the lab using spherical micro- and nanoparticles.

The result is that water droplets bead up when placed on films of the raspberry particles and they’re not able to drip down from it, even when turned upside down.

“Raspberry particle films can be described as sticky tape for water droplets,” Dr Telford said.

This could be useful in preventing condensation issues in airplane cabins. It could also help rapidly process simple medical tests on free-standing droplets, with the potential for very high turnover of tests with inexpensive equipment and in remote areas.

Other exciting applications are under study: if we use this nanotechnology to control how a surface is structured we can influence how it will interact with water.

“This means we will be able to design a surface that does whatever you need it to do.

“We could also design a surface that stays dry forever, never needs cleaning or able to repel bacteria or even prevent mould and fungi growth.

“We could then tweak the same structure by changing its composition so it forces water to spread very quickly.

“This could be used on quick-dry walls and roofs which would also help to cool down houses.

“This can only be achieved with a very clear understanding of the science behind the chemical properties and construction of the surface,” he said.

The discovery is also potentially viable commercially.

“Our team’s discovery is the first that allows for the preparation of raspberry particles on an industrial scale and we are now in a position where we can prepare large quantities of these particles without the need to build special plants or equipment,” Dr Telford said.

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

Mimicking the Wettability of the Rose Petal using Self-assembly of Waterborne Polymer Particles by A. M. Telford, B. S. Hawkett, C. Such, and C. Neto. Chem. Mater., 2013, 25 (17), pp 3472–3479 DOI: 10.1021/cm4016386 Publication Date (Web): July 23, 2013
Copyright © 2013 American Chemical Society

This paper is behind a paywall.

Touchie-feelie comes to the big screen (42 inches) in Amdolla/Cima NanoTech deal

If it’s been your dream to experience a really big touchscreen, you will be thrilled with this news. From a May 28, 2014 news item on Azonano (Note: A link has been removed),

Cima NanoTech, a smart nanomaterials company specializing in high performance transparent conductive films, announced today the industry’s first ultra responsive, non-ITO film-based, 42-inch projected capacitive multi-touch module for large format touch applications.

The module was built by Amdolla Group, a leader in advanced touch module manufacturing, using Cima NanoTech’s highly conductive, silver nanoparticle-based, SANTE® FS200 touch films. This product is targeted at applications including self-service kiosks, interactive tabletops, widescreen interactive digital signage, interactive flat panel displays, and other applications that require fast response, large size touch screens.

The Cima NanoTech May 28, 2014 news release (found on BusinessWire.com), which originated the news item, describes the technology in more detail,

With a scan rate of 150hz for 10-point multi-touch, rivaling the response time of smartphones and tablets, this jointly developed product dramatically increases the speed of large format touch displays. Unlike optical and infrared touch solutions, this module does not have a raised bezel for a smooth cover glass. In addition, the random conductive mesh pattern formed by SANTE® nanoparticle technology eliminates moiré, a challenge for traditional metal mesh technologies, thus enabling touch screens with better display quality.

“Our goal is to offer our customers a high performance, cost competitive and easy-to-implement solutions, and we’ve done it,” said Jon Brodd, CEO, Cima NanoTech. “Together with touch panel manufacturer, Amdolla, we are confident in creating a large format touch experience that is engaging and intuitive, and we expect to see this product on shelves by Q4 2014.”

SANTE® FS200 touch films are manufactured via a wide width roll-to-roll wet coating process. The high-throughput, high-yield manufacturing makes SANTE® nanoparticle technology a cost competitive solution for large format touch screens. Cima NanoTech also has the production capabilities to scale up to wider width touch films for screen sizes above 42”, further expanding the possibilities for innovative touch-enabled surfaces.

“The high response rate and excellent multi-point accuracy of the 42” touch module makes it a superior product in the industry, and we are very excited to be working with Cima NanoTech to commercialize this product,” commented Vance Zhang, General Manager, Amdolla Group. “We are also working to scale up to 55’’ screen sizes and larger.”

Here’s a little more about both companies from the news release (Note: Links have been removed),

 About Cima NanoTech

Cima NanoTech is a smart nanomaterials company delivering high performance, next-generation transparent conductors. The company developed its proprietary SANTE® nanoparticle technology, a silver nanoparticle conductive coating that self-assembles into a random mesh-like network when coated onto a substrate. SANTE® nanoparticle technology enables transparent conductors in a multitude of markets from large-format multi-touch displays to capacitive sensors, transparent and moldable EMI shielding, transparent heaters, transparent antennas, OLED lighting, electrochromic, and other flexible applications. Cima NanoTech has business development centers in the U.S., Singapore, Israel, Japan, Korea, Taiwan and China. For more information, visit www.cimananotech.com.

“Cima NanoTech” and “SANTE” are registered trademarks of Cima NanoTech, Inc., registered in the U.S. and other countries.

About Amdolla Group

Founded in Shenzhen, China, Amdolla Group specializes in joint-design, joint-development, manufacturing, assembly and after-sales services to global computer, communication and consumer electronics leaders. The company leverages its advanced manufacturing technology and experienced technical team to provide total solutions to its customers, including Apple, Intel, Lenovo, Huawei, TCL, and many others. Visit www.amdolla.com.cn or e-mail [email protected]

It looks like we’re a step closer to whole-body touchscreens.

Fungal infections, begone!

A May 7, 2014 news item on Nanowerk highlights some antifungal research at A*STAR (Singapore’s Agency for Science, Technology and Research),

Pathogenic fungi like Candida albicans can cause oral, skin, nail and genital infections. While exposure to pathogenic fungi is generally not life-threatening, it can be deadly to immunocompromised patients with AIDS or cancer. A variety of antifungal medications, such as triazoles and polyenes, are currently used for treating fungal infections. The range of these antifungal medications, however, is extremely limited, with some fungal species developing resistance to these drugs.

Yi Yan Yang at the A*STAR Institute of Bioengineering and Nanotechnology in Singapore and co-workers, in collaboration with IBM Almaden Research Center in the United States, have discovered four cationic terephthalamide-bisurea compounds with strong antifungal activity, excellent microbial selectivity and low host toxicity …

A May 7, 2018 A*STAR news release, which originated the news item, describes the research in detail (Note: A link has been removed),

Conformational analysis revealed that the terephthalamide-bisurea compounds have a Z-shaped structure: the terephthalamide sits in the middle, urea groups on both sides of the terephthalamide, and cationic charges at both ends. The researchers prepared compounds with different spacers — ethyl, butyl, hexyl or benzyl amine — in-between the urea group and the cationic charge.

When dissolved in water, the terephthalamide-bisurea compounds aggregate to form fibers with lengths ranging from a few hundred nanometers to several micrometers. Some of the compounds form fibers with high flexibility and others with high rigidity.

The researchers evaluated the antifungal activity of their terephthalamide-bisurea compounds against C. albicans. They found that all of the cationic compounds effectively inhibited fungal growth, even when the fungal concentration increased from 102 to 105 colony-forming units per milliliter.

The researchers believe that the potent antifungal activity is largely due to the formation of fibers with extremely small diameters in the order of 5 to 10 nanometers, which facilitates the rupture of fungal membranes. “This is particularly important because the fungal membrane of C. albicans is multilayered and has low negative charges,” explains Yang. “It also helps explain why cationic terephthalamide-bisurea compounds could easily penetrate the fungal membrane.”

The terephthalamide-bisurea compounds also eradicated clinically isolated drug-resistant C. albicans. The compounds prevent the development of drug resistance by rupturing the fungal membrane of C. albicans and disrupting the biofilm (see image).

Additionally, cytotoxicity tests showed that the cationic terephthalamide-bisurea compounds exhibit low toxicity toward mammalian cells and in a mouse model, revealing that the compounds “are relatively safe for preventing and treating fungal infections,” says Yang. [emphasis mine]

It’s nice to see that this potential anti-fungal treatment isn’t damaging to one’s cells.

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

Supramolecular high-aspect ratio assemblies with strong antifungal activity by Kazuki Fukushima, Shaoqiong Liu, Hong Wu, Amanda C. Engler, Daniel J. Coady, Hareem Maune, Jed Pitera, Alshakim Nelson, Nikken Wiradharma, Shrinivas Venkataraman, Yuan Huang, Weimin Fan, Jackie Y. Ying, Yi Yan Yang, & James L. Hedrick. Nature Communications 4, Article number: 286 doi:10.1038/ncomms3861 Published 09 December 2013

This article is behind a paywall.

Purple promises and bioimaging from Singapore’s A*STAR

A May 7, 2014 news item on Nanowerk describes a promising new approach to bioimaging,

Labeling biomolecules with light-emitting nanoparticles is a powerful technique for observing cell movement and signaling under realistic, in vivo conditions. The small size of these probes, however, often limits their optical capabilities. In particular, many nanoparticles have trouble producing high-energy light with wavelengths in the violet to ultraviolet range, which can trigger critical biological reactions.

Now, an international team led by Xiaogang Liu from the A*STAR Institute of Materials Research and Engineering and the National University of Singapore has discovered a novel class of rare-earth nanocrystals that preserve excited energy inside their atomic framework, resulting in unusually intense violet emissions …

A May 7, 2014 A*STAR (Agency for Science, Technology and Research) news release (h/t Imagist), which originated the news item, describes the problems with current bioimaging techniques and the new approach in more detail (Note: Links have been removed)

Nanocrystals selectively infused, or ‘doped’, with rare-earth ions have attracted the attention of researchers, because of their low toxicity and ability to convert low-energy laser light into violet-colored luminescence emissions — a process known as photon upconversion. Efforts to improve the intensity of these emissions have focused on ytterbium (Yb) rare-earth dopants, as they are easily excitable with standard lasers. Unfortunately, elevated amounts of Yb dopants can rapidly diminish, or ‘quench’, the generated light.

This quenching probably arises from the long-range migration of laser-excited energy states from Yb and toward defects in the nanocrystal. Most rare-earth nanocrystals have relatively uniform dopant distributions, but Liu and co-workers considered that a different crystal arrangement — clustering dopants into multi-atom arrays separated by large distances — could produce localized excited states that do not undergo migratory quenching.

The team screened numerous nanocrystals with different symmetries before discovering a material that met their criteria: a potassium fluoride crystal doped with Yb and europium rare earths (KYb2F7:Eu). Experiments revealed that the isolated Yb ‘energy clusters’ inside this pill-shaped nanocrystal (see image) enabled substantially higher dopant concentrations than usual — Yb accounted for up to 98 per cent of the crystal’s mass — and helped initiate multiphoton upconversion that yielded violet light with an intensity eight times higher than previously seen.

The researchers then explored the biological applications of their nanocrystals by using them to detect alkaline phosphatases, enzymes that frequently indicate bone and liver diseases. When the team brought the nanocrystals close to an alkaline phosphate-catalyzed reaction, they saw the violet emissions diminish in direct proportion to a chemical indicator produced by the enzyme. This approach enables swift and sensitive detection of this critical biomolecule at microscale concentration levels.

“We believe that the fundamental aspects of these findings — that crystal structures can greatly influence luminescence properties — could allow upconversion nanocrystals to eventually outperform conventional fluorescent biomarkers,” says Liu.

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

Enhancing multiphoton upconversion through energy clustering at sublattice level by Juan Wang, Renren Deng, Mark A. MacDonald, Bolei Chen, Jikang Yuan, Feng Wang, Dongzhi Chi, Tzi Sum Andy Hor, Peng Zhang, Guokui Liu, Yu Han, & Xiaogang Liu. Nature Materials 13, 157–162 (2014) doi:10.1038/nmat3804 Published online 24 November 2013

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

Self-healing supercapacitors from Singapore

Michael Berger has written up the latest and greatest regarding self-healing capacitors and carbon nanotubes (which could have more relevance to your life than you realize) in a March 10, 2014 Nanowerk Spotlight article,

If you ever had problems with the (non-removable) battery in your iPhone or iPad then you well know that the energy storage or power source is a key component in a tightly integrated electronic device. Any damage to the power source will usually result in the breakdown of the entire device, generating at best inconvenience and cost and in the worst case a safety hazard and your latest contribution to the mountains of electronic waste.

A solution to this problem might now be at hand thanks to researchers in Singapore who have successfully fabricated the first mechanically and electrically self-healing supercapacitor.

Reporting their findings in Advanced Materials (“A Mechanically and Electrically Self-Healing Supercapacitor”) a team led by Xiaodong Chen, an associate professor in the School of Materials Science & Engineering at Nanyang Technological University, have designed and fabricated the first integrated, mechanically and electrically self-healing supercapacitor by spreading functionalized single-walled carbon nanotube (SWCNT) films on self-healing substrates.

Inspired by the biological systems’ intrinsic self-repairing ability, a class of artificial ‘smart’ materials, called self-healing materials, which can repair internal or external damages have been developed over the past decade …

Berger goes on to describe how the researchers addressed the issue of restoring electrical conductivity, as well as, restoring mechanical properties to self-healing materials meant to be used as supercapacitors.

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

A Mechanically and Electrically Self-Healing Supercapacitor by Hua Wang, Bowen Zhu, Wencao Jiang, Yun Yang, Wan Ru Leow, Hong Wang, & Xiaodong Chen. Advanced Materials Article first published online: 19 FEB 2014 DOI: 10.1002/adma.201305682

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

Xiaodong Chen and his team were last mentioned here in a Jan. 9, 2014 posting in connection with their work on memristive nanodevices derived from protein.

Nanopolis and China’s Showroon for Nanotechnology

Courtesy: HENN [Architects] [downloaded from http://www.henn.com/en/projects/culture/nanopolis-showroom]

Courtesy: Henn Architects [downloaded from http://www.henn.com/en/projects/culture/nanopolis-showroom]

Marija Bojovic’s Jan. 17, 2014 article for evolo.us offers the preceding image and more in an article* where she describes the building (Note: Links have been removed),

The layout of the curved building follows the classical inner courtyard typology and its form makes reference to the interplay of three ellipses. The largest ellipse defines the external size of the building, the smallest, the inner courtyard and the middle, the roof edge. At the lowest point, the pronounced slope of the annular allows a second access across the inner courtyard and opens the building to the forecourt opposite and the city. At the same time, the building rises from this point and terminates in the glass facade, which extends over the full height of the building and faces toward the water-scape.

The Showroom for Nanotechnology is part of a larger complex called Nanopollis, which in turn is part of an industrial park, in the city of Suzhou, China. The Nanopolis complex is expected to be opened in 2015. Here’s more about the project according to the agency which is responsible for it (from the Suzhou Nanotechnology webpage on the the Nanopolis website),

Founded in September 2010 as a state-owned company of Suzhou Industrial Park, Suzhou Nanotech focuses on nanotech industry promotion and service to establish an ecosystem for nanotech innovation and commercialization. The company actively works on recruitment and cooperation with industry and innovation resources, R&D facilities and platforms set-up and operation, investment and incubation, marketing and supporting services as well as the construction of “Nanopolis Suzhou”. Nowadays we have two wholly-owned subsidiaries named as Suzhou Nano Venture Capital Co.,Ltd. and SIP Nanotechnology Industry Institute Co., Ltd.

6 main Functions

• Nanopolis construction and operation
• Industry & innovation introduction and cooperation
• Nanotech industry cluster development
• Public platform construction and operation
• Investment and incubation
• Industry promotion & brand establishment

I did find two slides (PDF) describing the project in more detail on the Netherlands Enterprise Agency website,

The SIP [Singapore jointly developed Suzhou Industrial Park] has committed 10 billion RMB (about 1.5 BUSD) for the next five years to further develop Suzhou high-tech industries including nanotech enabled industries. Today the SIP is housed with 20000 national and multinational companies including 3M, Samsung, Siemens, Johnson & Johnson, Phillips, AMD, Bosch, Eli Lily and others within 288 square kilometers. Suzhou was ranked top 3 in “2010 China’s Most Innovative Cities” by Forbes.

… Suzhou intends to attract over 200 nanotech companies from all over the world and 10,000 nanotech experts within the next 5 years to make Suzhou the most global and innovative nanotech hub in China by 2015.

I look forward to hearing more about Nanopolis when it opens. In the meantime, here’s what the architects have to say about their approach to the project (from the HENN Nanopolis webpage),

Suzhou has set itself the target of closing the gap on the world’s leaders as a research and development location. Alongside the Biobay biotechnology park in the west of the city, Nanotech City marks another key element in that strategy. The program includes a total of 1.3 million square metres of floor area.

The creative leitmotif of the design is the relationship of scale between the molecular world, man and urban space. All elements of urban, architectural and landscape design range in density, size and height from the very large to the very small. The fractal logic of the division into units of diminishing size continues from the urban scale down to the facades, where elements of local architecture are reflected in aspects such as colour and structure.

As for HENN, here’s a little more about the company from the company’s About Us webpage,

HENN is an international architectural consultancy with 65 years of expertise in the design and realisation of buildings, masterplans and interior spaces in the fields of culture, administration, teaching and research, development and production as well as urban design.

The office is led by Gunter Henn and eleven partners with offices in Munich, Berlin, Beijing and Shanghai. 350 employees from 25 countries are able to draw upon a wealth of knowledge collected over three generations of building experience in addition to a worldwide network of partners and experts in a variety of disciplines.

* ‘arti6cle’ corrected to ‘article’ on Sept. 25, 2014.