Tag Archives: University of Sydney

CRISPR [clustered regularly interspaced short palindromic repeats) has a metaphor issue?

Elinor Hortie at the University of Sydney (Australia) has written a very interesting essay about CRISPR ‘scissors’, a metaphor she find misleading. From Hortie’s July 4, 2019 essay on The Conversation,

Last week I read an article about CRISPR, the latest tool scientists are using to edit DNA. It was a great piece – well researched, beautifully written, factually accurate. It covered some of the amazing projects scientist are working on using CRISPR, like bringing animals back from extinction and curing diseases. It also gave me the heebies, but not for the reason you might expect.

Take CRISPR. It’s most often described as a pair of molecular scissors that can be used to modify DNA, the blueprint for life. And when we read that, I think most of us start imagining something like a child with her Lego bricks strewn in front of her, instruction booklet in one hand, scissors in the other. One set of pictograms, one model; one gene, one disease; one snip, one cure. We’re there in a blink. CRISPR seems like it can work miracles.

I want to stress that the molecular scissors metaphor is pretty damn accurate as far as it goes. But in focusing on the relatively simple relationship between CRISPR and DNA, we miss the far more complicated relationship between DNA and the rest of the body. This metaphor ignores an entire ecosystem of moving parts that are crucial for understanding the awe-inspiring, absolutely insane thing scientists are trying to do when they attempt gene editing.

Hortie proposes a different metaphor,

In my research I use CRISPR from time to time. To design experiments and interpret results effectively, I need a solid way to conceptualise what it can (and can’t) do. I do not think of CRISPR as molecular scissors.

Instead I imagine a city. The greater metropolis represents the body, the suburbs are organs, the buildings are cells, the people are proteins, and the internet is DNA.

In this metaphor CRISPR is malware. More precisely, CRISPR is malware that can search for any chosen 20-character line of code and corrupt it. This is not a perfect metaphor by any stretch, but it gets me closer to understanding than almost anything else.

Hortie offers an example from her own work demonstrating how a CRISPR ‘malware’ metaphor/analogy more accurately represents the experience of using the gene-editing system,

As an example, let’s look at Alzheimer’s, one of the diseases CRISPR is being touted to cure. The headlines are usually some variation of “CRISPR to correct Alzheimer’s gene!”, and the molecular scissors analogy is never far behind.

It seems reasonable to me that someone could read those words and assume that chopping away the disease-gene with the DNA-shears should be relatively simple. When the cure doesn’t appear within five years, I can understand why that same person would come to ask me why Big Pharma is holding out (this has happened to me more than once).

Now let’s see how it looks using the malware metaphor. The consensus is that Alzheimer’s manifests when a specific protein goes rogue, causing damage to cells and thereby stopping things from working properly inside the brain. It might have a genetic cause, but it’s complicated. In our allegorical city, what would that look like?

I think riots would come close. Rampaging humans (proteins) destroying houses and property (cells), thereby seriously derailing the normal functioning of a specific suburb (the brain).

And you want to fix that with malware?

It’s hard to predict the domino effect

Can you imagine for a second trying to stop soccer hooligans smashing things on the streets of Buenos Aires by corrupting roughly three words in the FIFA by-laws with what’s essentially a jazzed-up command-F function?

I’m not saying it’s not possible – it absolutely is.

But think of all the prior knowledge you need, and all the pieces that have to fall in place for that to work. You’d have to know that the riots are caused by football fans. You’d have to understand which rule was bothering them (heaven help you if it’s more than one), and if that rule causes drama at every game. You’d have to find a 20-character phrase that, when corrupted, would change how the rule was read, rather than just making a trivial typo.

You’d have to know that the relevant footballers have access to the updated rule book, and you’d have to know there were no other regulations making your chosen rule redundant. You’d have to know there aren’t any similar 20-character phrases anywhere on the internet that might get corrupted at the same time (like in the rules for presidential succession say, or in the nuclear warhead codes). Even then you’d still be rolling the dice.

Even if you stop the riots successfully, which of us really know the long-term consequences of changing the World Game forever?

That’s stretching the metaphor as Hortie notes herself later in the essay. And, she’s not the only one concerned about metaphors and CRISPR. There’s a December 8, 0217 article by Rebecca Robbins for STAT news which covers ten analogies/metaphors ranked from worst to best,

… Some of these analogies are better than others. To compile the definitive ranking, I sat down with STAT’s senior science writer Sharon Begley, a wordsmith who has herself compared CRISPR to “1,000 monkeys editing a Word document” and the kind of dog “you can train to retrieve everything from Frisbees to slippers to a cold beer.”

Sharon and I evaluated each of the metaphors we found by considering these three questions: Is it creative? Is it clear? And is it accurate? Below, our rankings of CRISPR analogies, ordered from worst to best:

0. A knockout punch


9. The hand of God


8. A bomb removal squad

It’s a very interesting list with a description of why each does and doesn’t work as an analogy. By the way, ‘scissors’ was not the top analogy. The number one spot went to ‘A Swiss army knife’.

There are many more essays than I would have believed concerning CRISPR and metaphors/analogies. I’m glad to see them as the language we use to describe our work and our world helps us understand it and can constrain us in unexpected ways. Critiques such as Hortie’s and the others can help us to refine the language and to recognize its limitations.

h/t July 4, 2019 news item on phys.org

Trounce biofouling with nanowrinkles

This is an example of what the researchers mean by ‘nanowrinkles’,

Caption: The Nepenthes pitcher plant (left) and its nanowrinkled ‘mouth’ (centre) inspired the engineered nanomaterial (right). Credit: Sydney Nano Courtesy: University of Sydney

As for ‘biofouling’, here’s my rough and ready description for anyone who might find it helpful, if you’ve been to the beach and slipped on some rocks, that slip was probably due to a biofilm and biofilm contributes to ‘biofouling’.

Australian scientists have announced research on a new technique for the eradication of biofouling according to a January 17, 2018 University of Sydney press release (also on EurekAlert but dated Jan. 16, 2018),

Sydney scientists have developed nanowrinkled coatings that could avoid the build-up of damaging biological material and save some of the $320 million annually spent by the Australian shipping industry because of biofouling.

A team of chemistry researchers from the University of Sydney Nano Institute has developed nanostructured surface coatings that have anti-fouling properties without using any toxic components.

Biofouling – the build-up of damaging biological material – is a huge economic issue, costing the aquaculture and shipping industries billions of dollars a year in maintenance and extra fuel usage. It is estimated that the increased drag on ship hulls due to biofouling costs the shipping industry in Australia $320 million a year a b.

Since the banning of the toxic anti-fouling agent tributyltin, the need for new non-toxic methods to stop marine biofouling has been pressing.

Leader of the research team, Associate Professor Chiara Neto, said: “We are keen to understand how these surfaces work and also push the boundaries of their application, especially for energy efficiency. Slippery coatings are expected to be drag-reducing, which means that objects, such as ships, could move through water with much less energy required.”

The new materials were tested tied to shark netting in Sydney’s Watson Bay, showing that the nanomaterials were efficient at resisting biofouling in a marine environment.

The research has been published in ACS Applied Materials & Interfaces.

The new coating uses ‘nanowrinkles’ inspired by the carnivorous Nepenthes pitcher plant. The plant traps a layer of water on the tiny structures around the rim of its opening. This creates a slippery layer causing insects to aquaplane on the surface, before they slip into the pitcher where they are digested.

Nanostructures utilise materials engineered at the scale of billionths of a metre – 100,000 times smaller than the width of a human hair. Associate Professor Neto’s group at Sydney Nano is developing nanoscale materials for future development in industry.

Biofouling can occur on any surface that is wet for a long period of time, for example aquaculture nets, marine sensors and cameras, and ship hulls. The slippery surface developed by the Neto group stops the initial adhesion of bacteria, inhibiting the formation of a biofilm from which larger marine fouling organisms can grow.

The interdisciplinary University of Sydney team included biofouling expert Professor Truis Smith-Palmer of St Francis Xavier University in Nova Scotia, Canada, who was on sabbatical visit to the Neto group for a year, partially funded by the Faculty of Science scheme for visiting women.

In the lab, the slippery surfaces resisted almost all fouling from a common species of marine bacteria, while control Teflon samples without the lubricating layer were completely fouled. Not satisfied with testing the surfaces under highly controlled lab conditions with only one type of bacteria the team also tested the surfaces in the ocean, with the help of marine biologist Professor Ross Coleman.

Test surfaces were attached to swimming nets at Watsons Bay baths in Sydney Harbour for a period of seven weeks. In the much harsher marine environment, the slippery surfaces were still very efficient at resisting fouling.

The antifouling coatings are mouldable and transparent, making their application ideal for underwater cameras and sensors.

Sources for economic data:
a) M. P. Schultz, J. A. Bendick, E. R. Holm, W. M. Hertel, Biofouling 2011, 27, 87-98;
b) Western Australia Departmet of Fisheries, in Fisheries Occasional Publication No. 115, 2012

Even though there’s a link to the paper in the excerpt, here’s a citation and another link to the paper,

Marine Antifouling Behavior of Lubricant-Infused Nanowrinkled Polymeric Surfaces by
Cameron S. Ware, Truis Smith-Palmer, Sam Peppou-Chapman, Liam R. J. Scarratt, Erin M. Humphries, Daniel Balzer, and Chiara Neto. ACS Appl. Mater. Interfaces, Article ASAP DOI: 10.1021/acsami.7b14736 Publication Date (Web): December 18, 2017

Copyright © 2017 American Chemical Society

This paper is behind a paywall.

Making graphene cheaply by using soybeans

One of the issues with new materials is being able to produce them in a commercially viable fashion and it seems that researchers in Australia may have helped  to do that with graphene. From a Feb. 15, 2017 news item on phys.org,

A breakthrough by CSIRO-led [Australia’s Commonwealth Scientific and Industrial Research Organisation] scientists has made the world’s strongest material more commercially viable, thanks to the humble soybean.

From a Feb. 15, (?) 2017 CSIRO press release (also on EurekAlert), which originated the news item, expands on the theme (Note: A link has been removed),

Graphene is a carbon material that is one atom thick.

Its thin composition and high conductivity means it is used in applications ranging from miniaturised electronics to biomedical devices.

These properties also enable thinner wire connections; providing extensive benefits for computers, solar panels, batteries, sensors and other devices.

Until now, the high cost of graphene production has been the major roadblock in its commercialisation.

Previously, graphene was grown in a highly-controlled environment with explosive compressed gases, requiring long hours of operation at high temperatures and extensive vacuum processing.

CSIRO scientists have developed a novel “GraphAir” technology which eliminates the need for such a highly-controlled environment.

The technology grows graphene film in ambient air with a natural precursor, making its production faster and simpler.

“This ambient-air process for graphene fabrication is fast, simple, safe, potentially scalable, and integration-friendly,” CSIRO scientist Dr Zhao Jun Han, co-author of the paper published today in Nature Communications said.

“Our unique technology is expected to reduce the cost of graphene production and improve the uptake in new applications.”

GraphAir transforms soybean oil – a renewable, natural material – into graphene films in a single step.

“Our GraphAir technology results in good and transformable graphene properties, comparable to graphene made by conventional methods,” CSIRO scientist and co-author of the study Dr Dong Han Seo said.

With heat, soybean oil breaks down into a range of carbon building units that are essential for the synthesis of graphene.

The team also transformed other types of renewable and even waste oil, such as those leftover from barbecues or cooking, into graphene films.

“We can now recycle waste oils that would have otherwise been discarded and transform them into something useful,” Dr Seo said.

The potential applications of graphene include water filtration and purification, renewable energy, sensors, personalised healthcare and medicine, to name a few.

Graphene has excellent electronic, mechanical, thermal and optical properties as well.

Its uses range from improving battery performance in energy devices, to cheaper solar panels.

CSIRO are looking to partner with industry to find new uses for graphene.

Researchers from The University of Sydney, University of Technology Sydney and The Queensland University of Technology also contributed to this work.

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

Single-step ambient-air synthesis of graphene from renewable precursors as electrochemical genosensor by Dong Han Seo, Shafique Pineda, Jinghua Fang, Yesim Gozukara, Samuel Yick, Avi Bendavid, Simon Kwai Hung Lam, Adrian T. Murdock, Anthony B. Murphy, Zhao Jun Han, & Kostya (Ken) Ostrikov. Nature Communications 8, Article number: 14217 (2017) doi:10.1038/ncomms14217 Published online: 30 January 2017

This is an open access paper.

Seeing the future with quantum computing

Researchers at the University of Sydney (Australia) have demonstrated the ability to see the ‘quantum future’ according to a Jan. 16, 2017 news item on ScienceDaily,

Scientists at the University of Sydney have demonstrated the ability to “see” the future of quantum systems, and used that knowledge to preempt their demise, in a major achievement that could help bring the strange and powerful world of quantum technology closer to reality.

The applications of quantum-enabled technologies are compelling and already demonstrating significant impacts — especially in the realm of sensing and metrology. And the potential to build exceptionally powerful quantum computers using quantum bits, or qubits, is driving investment from the world’s largest companies.

However a significant obstacle to building reliable quantum technologies has been the randomisation of quantum systems by their environments, or decoherence, which effectively destroys the useful quantum character.

The physicists have taken a technical quantum leap in addressing this, using techniques from big data to predict how quantum systems will change and then preventing the system’s breakdown from occurring.

A Jan. 14, 2017 University of Sydney press release (also on EurekAlert), which originated the news item, expands on the theme,

“Much the way the individual components in mobile phones will eventually fail, so too do quantum systems,” said the paper’s senior author Professor Michael J.  Biercuk.

“But in quantum technology the lifetime is generally measured in fractions of a second, rather than years.”

Professor Biercuk, from the University of Sydney’s School of Physics and a chief investigator at the Australian Research Council’s Centre of Excellence for Engineered Quantum Systems, said his group had demonstrated it was possible to suppress decoherence in a preventive manner. The key was to develop a technique to predict how the system would disintegrate.

Professor Biercuk highlighted the challenges of making predictions in a quantum world: “Humans routinely employ predictive techniques in our daily experience; for instance, when we play tennis we predict where the ball will end up based on observations of the airborne ball,” he said.

“This works because the rules that govern how the ball will move, like gravity, are regular and known.  But what if the rules changed randomly while the ball was on its way to you?  In that case it’s next to impossible to predict the future behavior of that ball.

“And yet this situation is exactly what we had to deal with because the disintegration of quantum systems is random. Moreover, in the quantum realm observation erases quantumness, so our team needed to be able to guess how and when the system would randomly break.

“We effectively needed to swing at the randomly moving tennis ball while blindfolded.”

The team turned to machine learning for help in keeping their quantum systems – qubits realised in trapped atoms – from breaking.

What might look like random behavior actually contained enough information for a computer program to guess how the system would change in the future. It could then predict the future without direct observation, which would otherwise erase the system’s useful characteristics.

The predictions were remarkably accurate, allowing the team to use their guesses preemptively to compensate for the anticipated changes.

Doing this in real time allowed the team to prevent the disintegration of the quantum character, extending the useful lifetime of the qubits.

“We know that building real quantum technologies will require major advances in our ability to control and stabilise qubits – to make them useful in applications,” Professor Biercuk said.

Our techniques apply to any qubit, built in any technology, including the special superconducting circuits being used by major corporations.

“We’re excited to be developing new capabilities that turn quantum systems from novelties into useful technologies. The quantum future is looking better all the time,” Professor Biercuk said.

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

Prediction and real-time compensation of qubit decoherence via machine learning by Sandeep Mavadia, Virginia Frey, Jarrah Sastrawan, Stephen Dona, & Michael J. Biercuk. Nature Communications 8, Article number: 14106 (2017) doi:10.1038/ncomms14106 Published online: 16 January 2017

This paper is open access.

‘Smart’ fabric that’s bony

Researchers at Australia’s University of New South of Wales (UNSW) have devised a means of ‘weaving’ a material that mimics *bone tissue, periosteum according to a Jan. 11, 2017 news item on ScienceDaily,

For the first time, UNSW [University of New South Wales] biomedical engineers have woven a ‘smart’ fabric that mimics the sophisticated and complex properties of one nature’s ingenious materials, the bone tissue periosteum.

Having achieved proof of concept, the researchers are now ready to produce fabric prototypes for a range of advanced functional materials that could transform the medical, safety and transport sectors. Patents for the innovation are pending in Australia, the United States and Europe.

Potential future applications range from protective suits that stiffen under high impact for skiers, racing-car drivers and astronauts, through to ‘intelligent’ compression bandages for deep-vein thrombosis that respond to the wearer’s movement and safer steel-belt radial tyres.

A Jan. 11, 2017 UNSW press release on EurekAlert, which originated the news item, expands on the theme,

Many animal and plant tissues exhibit ‘smart’ and adaptive properties. One such material is the periosteum, a soft tissue sleeve that envelops most bony surfaces in the body. The complex arrangement of collagen, elastin and other structural proteins gives periosteum amazing resilience and provides bones with added strength under high impact loads.

Until now, a lack of scalable ‘bottom-up’ approaches by researchers has stymied their ability to use smart tissues to create advanced functional materials.

UNSW’s Paul Trainor Chair of Biomedical Engineering, Professor Melissa Knothe Tate, said her team had for the first time mapped the complex tissue architectures of the periosteum, visualised them in 3D on a computer, scaled up the key components and produced prototypes using weaving loom technology.

“The result is a series of textile swatch prototypes that mimic periosteum’s smart stress-strain properties. We have also demonstrated the feasibility of using this technique to test other fibres to produce a whole range of new textiles,” Professor Knothe Tate said.

In order to understand the functional capacity of the periosteum, the team used an incredibly high fidelity imaging system to investigate and map its architecture.

“We then tested the feasibility of rendering periosteum’s natural tissue weaves using computer-aided design software,” Professor Knothe Tate said.

The computer modelling allowed the researchers to scale up nature’s architectural patterns to weave periosteum-inspired, multidimensional fabrics using a state-of-the-art computer-controlled jacquard loom. The loom is known as the original rudimentary computer, first unveiled in 1801.

“The challenge with using collagen and elastin is their fibres, that are too small to fit into the loom. So we used elastic material that mimics elastin and silk that mimics collagen,” Professor Knothe Tate said.

In a first test of the scaled-up tissue weaving concept, a series of textile swatch prototypes were woven, using specific combinations of collagen and elastin in a twill pattern designed to mirror periosteum’s weave. Mechanical testing of the swatches showed they exhibited similar properties found in periosteum’s natural collagen and elastin weave.

First author and biomedical engineering PhD candidate, Joanna Ng, said the technique had significant implications for the development of next-generation advanced materials and mechanically functional textiles.

While the materials produced by the jacquard loom have potential manufacturing applications – one tyremaker believes a titanium weave could spawn a new generation of thinner, stronger and safer steel-belt radials – the UNSW team is ultimately focused on the machine’s human potential.

“Our longer term goal is to weave biological tissues – essentially human body parts – in the lab to replace and repair our failing joints that reflect the biology, architecture and mechanical properties of the periosteum,” Ms Ng said.

An NHMRC development grant received in November [2016] will allow the team to take its research to the next phase. The researchers will work with the Cleveland Clinic and the University of Sydney’s Professor Tony Weiss to develop and commercialise prototype bone implants for pre-clinical research, using the ‘smart’ technology, within three years.

In searching for more information about this work, I found a Winter 2015 article (PDF; pp. 8-11) by Amy Coopes and Steve Offner for UNSW Magazine about Knothe Tate and her work (Note: In Australia, winter would be what we in the Northern Hemisphere consider summer),

Tucked away in a small room in UNSW’s Graduate School of Biomedical Engineering sits a 19th century–era weaver’s wooden loom. Operated by punch cards and hooks, the machine was the first rudimentary computer when it was unveiled in 1801. While on the surface it looks like a standard Jacquard loom, it has been enhanced with motherboards integrated into each of the loom’s five hook modules and connected to a computer. This state-of-the-art technology means complex algorithms control each of the 5,000 feed-in fibres with incredible precision.

That capacity means the loom can weave with an extraordinary variety of substances, from glass and titanium to rayon and silk, a development that has attracted industry attention around the world.

The interest lies in the natural advantage woven materials have over other manufactured substances. Instead of manipulating material to create new shades or hues as in traditional weaving, the fabrics’ mechanical properties can be modulated, to be stiff at one end, for example, and more flexible at the other.

“Instead of a pattern of colours we get a pattern of mechanical properties,” says Melissa Knothe Tate, UNSW’s Paul Trainor Chair of Biomedical Engineering. “Think of a rope; it’s uniquely good in tension and in bending. Weaving is naturally strong in that way.”


The interface of mechanics and physiology is the focus of Knothe Tate’s work. In March [2015], she travelled to the United States to present another aspect of her work at a meeting of the international Orthopedic Research Society in Las Vegas. That project – which has been dubbed “Google Maps for the body” – explores the interaction between cells and their environment in osteoporosis and other degenerative musculoskeletal conditions such as osteoarthritis.

Using previously top-secret semiconductor technology developed by optics giant Zeiss, and the same approach used by Google Maps to locate users with pinpoint accuracy, Knothe Tate and her team have created “zoomable” anatomical maps from the scale of a human joint down to a single cell.

She has also spearheaded a groundbreaking partnership that includes the Cleveland Clinic, and Brown and Stanford universities to help crunch terabytes of data gathered from human hip studies – all processed with the Google technology. Analysis that once took 25 years can now be done in a matter of weeks, bringing researchers ever closer to a set of laws that govern biological behaviour. [p. 9]

I gather she was recruited from the US to work at the University of New South Wales and this article was to highlight why they recruited her and to promote the university’s biomedical engineering department, which she chairs.

Getting back to 2017, here’s a link to and citation for the paper,

Scale-up of nature’s tissue weaving algorithms to engineer advanced functional materials by Joanna L. Ng, Lillian E. Knothe, Renee M. Whan, Ulf Knothe & Melissa L. Knothe Tate. Scientific Reports 7, Article number: 40396 (2017) doi:10.1038/srep40396 Published online: 11 January 2017

This paper is open access.

One final comment, that’s a lot of people (three out of five) with the last name Knothe in the author’s list for the paper.

*’the bone tissue’ changed to ‘bone tissue’ on July 17,2017.

Nanoscale elements that govern the behaviour of our teeth

Are we going to be adopting atomically correct dental hygiene practices in the future? It’s certainly a possibility given the latest Australian research announced in a Sept. 7, 2016 news item on Nanowerk (Note: A link has been removed),

With one in two Australian children reported to have tooth decay in their permanent teeth by age 12, researchers from the University of Sydney believe they have identified some nanoscale elements that govern the behaviour of our teeth.

Material and structures engineers worked with dentists and bioengineers to map the exact composition and structure of tooth enamel at the atomic scale.

Using a relatively new microscopy technique called atom probe tomography, their work produced the first-ever three-dimensional maps showing the positions of atoms critical in the decay process.

The new knowledge on atom composition at the nanolevel has the potential to aid oral health hygiene and caries prevention, and has been published today in the journal Science Advances(“Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel”).

A Sept. 8, 2016 University of Sydney press release, which originated the news item, expands on the theme (Note: A link has been removed),

Professor Julie Cairney, Material and Structures Engineer in the Faculty of Engineering and Information Technologies, said:

“The dental professionals have known that certain trace ions are important in the tough structure of tooth enamel but until now it had been impossible to map the ions in detail.

“The structure of human tooth enamel is extremely intricate and while we have known that magnesium, carbonate and fluoride ions influence enamel properties scientists have never been able to capture its structure at a high enough resolution or definition.”

“What we have found are the magnesium-rich regions between the hydroxyapatite nanorods that make up the enamel.”

“This means we have the first direct evidence of the existence of a proposed amorphous magnesium-rich calcium phosphate phase that plays an essential role in governing the behaviour of teeth. “

Co-lead researcher on the study, Dr Alexandre La Fontaine from the University’s Australian Centre for Microscopy and Microanalysis, said:

“We were also able to see nanoscale ‘clumps’ of organic material, which indicates that proteins and peptides are heterogeneously distributed within the enamel rather than present along all the nanorod interfaces, which was what was previously suggested.

“The mapping has the potential for new treatments designed around protecting against the dissolution of this specific amorphous phase.

“The new understanding of how enamel forms will also help in tooth remineralisation research.”

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

Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel by Alexandre La Fontaine, Alexander Zavgorodniy, Howgwei Liu, Rongkun Zheng, Michael Swain, and Julie Cairney. Science Advances  07 Sep 2016: Vol. 2, no. 9, e1601145 DOI: 10.1126/sciadv.1601145

This paper is open access.

Crowd computing for improved nanotechnology-enabled water filtration

This research is the product of a China/Israel/Switzerland collaboration on water filtration with involvement from the UK and Australia. Here’s some general information about the importance of water and about the collaboration in a July 5, 2015 news item on Nanowerk (Note: A link has been removed),

Nearly 800 million people worldwide don’t have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. Together, unsafe drinking water and the inadequate supply of water for hygiene purposes contribute to almost 90% of all deaths from diarrheal diseases — and effective water sanitation interventions are still challenging scientists and engineers.

A new study published in Nature Nanotechnology (“Water transport inside carbon nanotubes mediated by phonon-induced oscillating friction”) proposes a novel nanotechnology-based strategy to improve water filtration. The research project involves the minute vibrations of carbon nanotubes called “phonons,” which greatly enhance the diffusion of water through sanitation filters. The project was the joint effort of a Tsinghua University-Tel Aviv University research team and was led by Prof. Quanshui Zheng of the Tsinghua Center for Nano and Micro Mechanics and Prof. Michael Urbakh of the TAU School of Chemistry, both of the TAU-Tsinghua XIN Center, in collaboration with Prof. Francois Grey of the University of Geneva.

A July 5, 2015 American Friends of Tel Aviv University news release (also on EurekAlert), which originated the news item, provides more details about the work,

“We’ve discovered that very small vibrations help materials, whether wet or dry, slide more smoothly past each other,” said Prof. Urbakh. “Through phonon oscillations — vibrations of water-carrying nanotubes — water transport can be enhanced, and sanitation and desalination improved. Water filtration systems require a lot of energy due to friction at the nano-level. With these oscillations, however, we witnessed three times the efficiency of water transport, and, of course, a great deal of energy saved.”

The research team managed to demonstrate how, under the right conditions, such vibrations produce a 300% improvement in the rate of water diffusion by using computers to simulate the flow of water molecules flowing through nanotubes. The results have important implications for desalination processes and energy conservation, e.g. improving the energy efficiency for desalination using reverse osmosis membranes with pores at the nanoscale level, or energy conservation, e.g. membranes with boron nitride nanotubes.

Crowdsourcing the solution

The project, initiated by IBM’s World Community Grid, was an experiment in crowdsourced computing — carried out by over 150,000 volunteers who contributed their own computing power to the research.

“Our project won the privilege of using IBM’s world community grid, an open platform of users from all around the world, to run our program and obtain precise results,” said Prof. Urbakh. “This was the first project of this kind in Israel, and we could never have managed with just four students in the lab. We would have required the equivalent of nearly 40,000 years of processing power on a single computer. Instead we had the benefit of some 150,000 computing volunteers from all around the world, who downloaded and ran the project on their laptops and desktop computers.

“Crowdsourced computing is playing an increasingly major role in scientific breakthroughs,” Prof. Urbakh continued. “As our research shows, the range of questions that can benefit from public participation is growing all the time.”

The computer simulations were designed by Ming Ma, who graduated from Tsinghua University and is doing his postdoctoral research in Prof. Urbakh’s group at TAU. Ming catalyzed the international collaboration. “The students from Tsinghua are remarkable. The project represents the very positive cooperation between the two universities, which is taking place at XIN and because of XIN,” said Prof. Urbakh.

Other partners in this international project include researchers at the London Centre for Nanotechnology of University College London; the University of Geneva; the University of Sydney and Monash University in Australia; and the Xi’an Jiaotong University in China. The researchers are currently in discussions with companies interested in harnessing the oscillation knowhow for various commercial projects.

 

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

Water transport inside carbon nanotubes mediated by phonon-induced oscillating friction by Ming Ma, François Grey, Luming Shen, Michael Urbakh, Shuai Wu,    Jefferson Zhe Liu, Yilun Liu, & Quanshui Zheng. Nature Nanotechnology (2015) doi:10.1038/nnano.2015.134 Published online 06 July 2015

This paper is behind a paywall.

Final comment, I find it surprising that they used labour and computing power from 150,000 volunteers and didn’t offer open access to the paper. Perhaps the volunteers got their own copy? I certainly hope so.

Nanotechnology risk perceptions in 2015 from Australia

I haven’t stumbled across a study on the perceptions of risk and nanotechnology in quite a while.  Before commenting on this latest research from the University of Sydney, here’s a link to and a citation for this new Australian study, which is an open access paper,

Perceptions of risk from nanotechnologies and trust in stakeholders: a cross sectional study of public, academic, government and business attitudes by Adam Capon, James Gillespie, Margaret Rolfe, and Wayne Smith. BMC Public Health 2015, 15:424 Published April 26, 2015  DOI: 10.1186/s12889-015-1795-1

According to the authors, this is the first study that surveyed the general public, academics, government officials, and business people with an eye to distinguishing any differences that might exist in their attitudes,

Our study proposes to extend and develop the knowledge base regarding perceptions of risk from nanotechnology and trust by stakeholders. To do this we use a standardised questionnaire across all the stakeholders surveyed. Secondly we examine stakeholder groups beyond highly published scientists and people attending nano conferences/working in nano laboratories that had previously been surveyed to include academic, government and business stakeholders. These three groups were chosen not just for their expertise, but because they represent the interplay of stakeholders most likely to shape policy in this field. Thirdly we seek and report on views of general risk perception (to health) and for specific products (food, cosmetics and sunscreens, medicines, pesticides, tennis racquets and computers) which broadly represent Australian regulatory arms [22]. Finally we explore several trust actors (health department, scientists, journalists and politicians), all of who have the ability to shape policy.

Our study aims to test six hypotheses. First, very little targeted research has been undertaken on differing stakeholder views of risks from nanotechnology. To explore this we hypothesise that public perceptions of risks from nanotechnology will be greater than those held by ‘experts’. Second, existing studies suggest that food and health applications of nanotechnology are likely to arouse more controversy [23]. We will test the hypothesis that the public, academics, government and business respondents will all perceive a higher level of risk in nanotechnologies that penetrate or have close and prolonged contact with the body. Three, there is inconsistent evidence that increased familiarity with nanotechnology is associated with differing perceptions of nanotechnologies [24]. Our third hypothesis proposes that public self-reported familiarity with nanotechnology will be associated with a reduction in risk perception. This relationship will be found with each of the nano products in the study. Four, the public holds less trust in the government agencies with responsibility for regulating nanotechnology than that expressed by people working in nanotechnology based industries/researching nanotechnology [23]. Our fourth hypothesis tests the evidence for this proposition. We hypothesise that the trust the public vests in scientists, the health department, journalists and politicians will be less than those held by business, academic, and government respondents who have an interest in nanotechnology.

The last two hypotheses expand on hypothesis four, examining the trust of the public in greater detail. Studies have shown that the Australian public are more likely to trust scientists and scientific institutions, followed by government agencies with industry and mass media holding the least amount of trust [25],[26]. In our fifth hypothesis we test the proposition that the public will have greatest trust in scientists, followed by the health department with trust in journalists and politicians below these two. Finally, public trust in business leaders [27], science and consumer protection agencies [28] and government agencies [29] have all been associated with decreased nano risk perception. Examining other stakeholders, the greater trust that people working in nanotechnology based industries or researching nanotechnology had with scientists and government agencies, the less they perceived risk from nanotechnology [23],[30]. Our sixth hypothesis is that significant negative associations exist between the trust the public vest in scientists, health department, journalists and politicians and perceived risk of nanotechnology, both when this risk is considered to health and across all risk applications. Understanding this relationship between trust and risk perception is an important avenue for risk communication and education.

As interesting as I find methodology I’m going to skip most of it and focus on the sample size and demographics,

The surveys consisted of 1355 public, 301 academic, 19 government and 21 business responses. Gender representation of the weighted public survey population was comparable to the June 2012 Australian population estimates of approximately 50% male and female. Gender representationa for academic and business responses was more likely to be male (≈70%) while the gender of government respondents was almost evenly balanced.

Three hundred and ninety eight public respondents (30%) were categorised as having no familiarity with nanotechnology, while 528 (39%) were categorised as having some familiarity and 422 (31%) as having moderate familiarity with nanotechnology.

Amongst the academic responses, the best represented area of research (38%) was in the field of nanomaterials. Nanocharacterisation, nanofabrication, nanobiotechnology/nanomedicine, nanoscale theory/computation, nanophotonics, and nanoelectronics/nanomagnetics represented between 15% to 4% per discipline in descending order. The least represented discipline was translational nanoresearch (2%), of which half were involved in nanotoxicology and the other either in ethical or social research on risk/public attitudes/public impact or did not provide a sub specialisation. Of the business responses the greatest percentage of business involvement was in nanomaterial manufacture, importation or research (33% – 23%). Importation of products containing nanomaterials, waste collection/processing and legal issues had little representation. The highest representation of government respondents was health and safety (37%) followed by communication/social impact (26%), business development (16%) and environment (11%).

The analysis of the results is well worth reading,

The Australian public perceives greater risks from manufactured nanomaterials and shows less trust in scientists and the health department to provide protection from possible health effects than academic, business and government stakeholders in the nanotechnology sector. Food applications and cosmetics/sunscreens loom high on the list of public concerns, although medicines and pesticides are also causes of public concern. Policy makers should be aware of these risk and trust disparities and address public sentiment by treating nanotechnology applications in the higher risk areas with greater caution. Risk communication is best placed in the hands of trusted scientists.

I am a little surprised that no mention was made of the nanosunscreen situation of 2012 where a research study found that 13% (originally reported as 17%) of Australians surveyed said they didn’t use any sunscreens due to fear of nanoparticles. I have the story in my Feb. 9, 2012 posting. Be sure to read through to the end as there were a couple of updates.

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.