Tag Archives: Yi Cui

Cooling the skin with plastic clothing

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Rather that cooling or heating an entire room, why not cool or heat the person? Engineers at Stanford University (California, US) have developed a material that helps with half of that premise: cooling. From a Sept. 1, 2016 news item on ScienceDaily,

Stanford engineers have developed a low-cost, plastic-based textile that, if woven into clothing, could cool your body far more efficiently than is possible with the natural or synthetic fabrics in clothes we wear today.

Describing their work in Science, the researchers suggest that this new family of fabrics could become the basis for garments that keep people cool in hot climates without air conditioning.

“If you can cool the person rather than the building where they work or live, that will save energy,” said Yi Cui, an associate professor of materials science and engineering and of photon science at Stanford.

A Sept. 1, 2016 Stanford University news release (also on EurekAlert) by Tom Abate, which originated the news item, further explains the information in the video,

This new material works by allowing the body to discharge heat in two ways that would make the wearer feel nearly 4 degrees Fahrenheit cooler than if they wore cotton clothing.

The material cools by letting perspiration evaporate through the material, something ordinary fabrics already do. But the Stanford material provides a second, revolutionary cooling mechanism: allowing heat that the body emits as infrared radiation to pass through the plastic textile.

All objects, including our bodies, throw off heat in the form of infrared radiation, an invisible and benign wavelength of light. Blankets warm us by trapping infrared heat emissions close to the body. This thermal radiation escaping from our bodies is what makes us visible in the dark through night-vision goggles.

“Forty to 60 percent of our body heat is dissipated as infrared radiation when we are sitting in an office,” said Shanhui Fan, a professor of electrical engineering who specializes in photonics, which is the study of visible and invisible light. “But until now there has been little or no research on designing the thermal radiation characteristics of textiles.”

Super-powered kitchen wrap

To develop their cooling textile, the Stanford researchers blended nanotechnology, photonics and chemistry to give polyethylene – the clear, clingy plastic we use as kitchen wrap – a number of characteristics desirable in clothing material: It allows thermal radiation, air and water vapor to pass right through, and it is opaque to visible light.

The easiest attribute was allowing infrared radiation to pass through the material, because this is a characteristic of ordinary polyethylene food wrap. Of course, kitchen plastic is impervious to water and is see-through as well, rendering it useless as clothing.

The Stanford researchers tackled these deficiencies one at a time.

First, they found a variant of polyethylene commonly used in battery making that has a specific nanostructure that is opaque to visible light yet is transparent to infrared radiation, which could let body heat escape. This provided a base material that was opaque to visible light for the sake of modesty but thermally transparent for purposes of energy efficiency.

They then modified the industrial polyethylene by treating it with benign chemicals to enable water vapor molecules to evaporate through nanopores in the plastic, said postdoctoral scholar and team member Po-Chun Hsu, allowing the plastic to breathe like a natural fiber.

Making clothes

That success gave the researchers a single-sheet material that met their three basic criteria for a cooling fabric. To make this thin material more fabric-like, they created a three-ply version: two sheets of treated polyethylene separated by a cotton mesh for strength and thickness.

To test the cooling potential of their three-ply construct versus a cotton fabric of comparable thickness, they placed a small swatch of each material on a surface that was as warm as bare skin and measured how much heat each material trapped.

“Wearing anything traps some heat and makes the skin warmer,” Fan said. “If dissipating thermal radiation were our only concern, then it would be best to wear nothing.”

The comparison showed that the cotton fabric made the skin surface 3.6 F warmer than their cooling textile. The researchers said this difference means that a person dressed in their new material might feel less inclined to turn on a fan or air conditioner.

The researchers are continuing their work on several fronts, including adding more colors, textures and cloth-like characteristics to their material. Adapting a material already mass produced for the battery industry could make it easier to create products.

“If you want to make a textile, you have to be able to make huge volumes inexpensively,” Cui said.

Fan believes that this research opens up new avenues of inquiry to cool or heat things, passively, without the use of outside energy, by tuning materials to dissipate or trap infrared radiation.

“In hindsight, some of what we’ve done looks very simple, but it’s because few have really been looking at engineering the radiation characteristics of textiles,” he said.

Dexter Johnson (Nanoclast blog on the IEEE [Institute of Electrical and Electronics Engineers] website) has written a Sept. 2, 2016 posting where he provides more technical detail about this work,

The nanoPE [nanoporous polyethylene] material is able to achieve this release of the IR heat because of the size of the interconnected pores. The pores can range in size from 50 to 1000 nanometers. They’re therefore comparable in size to wavelengths of visible light, which allows the material to scatter that light. However, because the pores are much smaller than the wavelength of infrared light, the nanoPE is transparent to the IR.

It is this combination of blocking visible light and allowing IR to pass through that distinguishes the nanoPE material from regular polyethylene, which allows similar amounts of IR to pass through, but can only block 20 percent of the visible light compared to nanoPE’s 99 percent opacity.

The Stanford researchers were also able to improve on the water wicking capability of the nanoPE material by using a microneedle punching technique and coating the material with a water-repelling agent. The result is that perspiration can evaporate through the material unlike with regular polyethylene.

For those who wish to further pursue their interest, Dexter has a lively writing style and he provides more detail and insight in his posting.

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

Radiative human body cooling by nanoporous polyethylene textile by Po-Chun Hsu, Alex Y. Song, Peter B. Catrysse, Chong Liu, Yucan Peng, Jin Xie, Shanhui Fan, Yi Cui. Science  02 Sep 2016: Vol. 353, Issue 6303, pp. 1019-1023 DOI: 10.1126/science.aaf5471

This paper is open access.

No more kevlar-wrapped lithium-ion batteries?

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Current lithium-ion batteries present a fire hazard, which is why, last, year a team of researchers at the University of Michigan came up with a plan to prevent fires by wrapping the batteries in kevlar. My Jan. 30, 2015 post describes the research and provides some information about airplane fires caused by the use of lithium-ion batteries.

This year, a team of researchers at Stanford University (US) have invented a lithium-ion (li-ion) battery that shuts itself down when it overheats, according to a Jan. 12, 2016 news item on Nanotechnology Now,

Stanford researchers have developed the first lithium-ion battery that shuts down before overheating, then restarts immediately when the temperature cools.

The new technology could prevent the kind of fires that have prompted recalls and bans on a wide range of battery-powered devices, from recliners and computers to navigation systems and hoverboards [and on airplanes].

“People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries,” said Zhenan Bao, a professor of chemical engineering at Stanford. “We’ve designed the first battery that can be shut down and revived over repeated heating and cooling cycles without compromising performance.”

Stanford has produced a video of Dr. Bao discussing her latest work,

A Jan. 11, 2016 Stanford University news release by Mark Schwartz, which originated the news item, provides more detail about li-ion batteries and the new fire prevention technology,

A typical lithium-ion battery consists of two electrodes and a liquid or gel electrolyte that carries charged particles between them. Puncturing, shorting or overcharging the battery generates heat. If the temperature reaches about 300 degrees Fahrenheit (150 degrees Celsius), the electrolyte could catch fire and trigger an explosion.

Several techniques have been used to prevent battery fires, such as adding flame retardants to the electrolyte. In 2014, Stanford engineer Yi Cui created a “smart” battery that provides ample warning before it gets too hot.

“Unfortunately, these techniques are irreversible, so the battery is no longer functional after it overheats,” said study co-author Cui, an associate professor of materials science and engineering and of photon science. “Clearly, in spite of the many efforts made thus far, battery safety remains an important concern and requires a new approach.”

Nanospikes

To address the problem Cui, Bao and postdoctoral scholar Zheng Chen turned to nanotechnology. Bao recently invented a wearable sensor to monitor human body temperature. The sensor is made of a plastic material embedded with tiny particles of nickel with nanoscale spikes protruding from their surface.

For the battery experiment, the researchers coated the spiky nickel particles with graphene, an atom-thick layer of carbon, and embedded the particles in a thin film of elastic polyethylene.

“We attached the polyethylene film to one of the battery electrodes so that an electric current could flow through it,” said Chen, lead author of the study. “To conduct electricity, the spiky particles have to physically touch one another. But during thermal expansion, polyethylene stretches. That causes the particles to spread apart, making the film nonconductive so that electricity can no longer flow through the battery.”

When the researchers heated the battery above 160 F (70 C), the polyethylene film quickly expanded like a balloon, causing the spiky particles to separate and the battery to shut down. But when the temperature dropped back down to 160 F (70 C), the polyethylene shrunk, the particles came back into contact, and the battery started generating electricity again.

“We can even tune the temperature higher or lower depending on how many particles we put in or what type of polymer materials we choose,” said Bao, who is also a professor, by courtesy, of chemistry and of materials science and engineering. “For example, we might want the battery to shut down at 50 C or 100 C.”

Reversible strategy

To test the stability of new material, the researchers repeatedly applied heat to the battery with a hot-air gun. Each time, the battery shut down when it got too hot and quickly resumed operating when the temperature cooled.

“Compared with previous approaches, our design provides a reliable, fast, reversible strategy that can achieve both high battery performance and improved safety,” Cui said. “This strategy holds great promise for practical battery applications.”

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

Fast and reversible thermoresponsive polymer switching materials for safer batteries by Zheng Chen, Po-Chun Hsu, Jeffrey Lopez, Yuzhang Li, John W. F. To, Nan Liu, Chao Wang, Sean C. Andrews, Jia Liu, Yi Cui, & Zhenan Bao. Nature Energy 1, Article number: 15009 (2016) doi:10.1038/nenergy.2015.9 Published online: 11 January 2016

This paper appears to be open access.

A new approach to heating: warm the clothing not the room

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A Jan. 7, 2015 news item on ScienceDaily describes a new type of textile which could change the way we use heat (energy),

To stay warm when temperatures drop outside, we heat our indoor spaces — even when no one is in them. But scientists have now developed a novel nanowire coating for clothes that can both generate heat and trap the heat from our bodies better than regular clothes. They report on their technology, which could help us reduce our reliance on conventional energy sources, in the ACS journal Nano Letters.

A Jan. 7, 2015 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item, provides more information about energy consumption and the researchers’ proposed solution,

Yi Cui [Stanford University] and colleagues note that nearly half of global energy consumption goes toward heating buildings and homes. But this comfort comes with a considerable environmental cost – it’s responsible for up to a third of the world’s total greenhouse gas emissions. Scientists and policymakers have tried to reduce the impact of indoor heating by improving insulation and construction materials to keep fuel-generated warmth inside. Cui’s team wanted to take a different approach and focus on people rather than spaces.

The researchers developed lightweight, breathable mesh materials that are flexible enough to coat normal clothes. When compared to regular clothing material, the special nanowire cloth trapped body heat far more effectively. Because the coatings are made out of conductive materials, they can also be actively warmed with an electricity source to further crank up the heat. The researchers calculated that their thermal textiles could save about 1,000 kilowatt hours per person every year — that’s about how much electricity an average U.S. home consumes in one month.

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

Personal Thermal Management by Metallic Nanowire-Coated Textile by Po-Chun Hsu, Xiaoge Liu, Chong Liu, Xing Xie, Hye Ryoung Lee, Alex J. Welch, Tom Zhao, and Yi Cui. Nano Lett., Article ASAP DOI: 10.1021/nl5036572 Publication Date (Web): November 30, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.

Keeping it together—new glue for lithium-ion batteries

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Glue isn’t the first component that comes to my mind when discussing ways to make lithium-ion (Li-ion) batteries more efficient but researchers at SLAC National Accelerator Laboratory at Stanford University have proved that the glue used to bind a Li-ion battery together can make a difference to its efficiency (from the Aug. 20, 2013 news item on phys.org),

When it comes to improving the performance of lithium-ion batteries, no part should be overlooked – not even the glue that binds materials together in the cathode, researchers at SLAC and Stanford have found.

Tweaking that material, which binds lithium sulfide and carbon particles together, created a cathode that lasted five times longer than earlier designs, according to a report published last month in Chemical Science. The research results are some of the earliest supported by the Department of Energy’s Joint Center for Energy Storage Research.

“We were very impressed with how important this binder was in improving the lifetime of our experimental battery,” said Yi Cui, an associate professor at SLAC and Stanford who led the research.

The Aug. 19, 2013 SLAC news release by Mike Ross, which originated the news item, provides context for this accidental finding about glue and Li-ion batteries,

Researchers worldwide have been racing to improve lithium-ion batteries, which are one of the most promising technologies for powering increasingly popular devices such as mobile electronics and electric vehicles. In theory, using silicon and sulfur as the active elements in the batteries’ terminals, called the anode and cathode, could allow lithium-ion batteries to store up to five times more energy than today’s best versions. But finding specific forms and formulations of silicon and sulfur that will last for several thousand charge-discharge cycles during real-life use has been difficult.

Cui’s group was exploring how to create a better cathode by using lithium sulfide rather than sulfur. The lithium atoms it contains can provide the ions that shuttle between anode and cathode during the battery’s charge/discharge cycle; this in turn means the battery’s other electrode can be made from a non-lithium material, such as silicon. Unfortunately, lithium sulfide is also electrically insulating, which greatly reduces any battery’s performance. To overcome this, electrically conducting carbon particles can be mixed with the sulfide; a glue-like material – the binder – holds it all together.

Scientists in Cui’s [Yi Cui, an associate professor at SLAC and Stanford who led the research] group devised a new binder that is particularly well-suited for use with a lithium sulfide cathode ­– and that also binds strongly with intermediate polysulfide molecules that dissolve out of the cathode and diminish the battery’s storage capacity and useful lifetime.

The experimental battery using the new binder, known by the initials PVP, retained 94 percent of its original energy-storage capacity after 100 charge/discharge cycles, compared with 72 percent for cells using a conventionally-used binder, known as PVDF. After 500 cycles, the PVP battery still had 69 percent of its initial capacity.

Cui said the improvement was due to PVP’s much stronger affinity for lithium sulfide; together they formed a fine-grained lithium sulfide/carbon composite that made it easier for lithium ions to penetrate and reach all of the active material within the cathode. In contrast, the previous binder, PVDF, caused the composite to grow into large clumps, which hindered the lithium ions’ penetration and ruined the battery within 100 cycles

Even the best batteries lose some energy-storage capacity with each charge/discharge cycle. Researchers aim to reduce such losses as much as possible. Further enhancements to the PVP/lithium sulfide cathode combination will be needed to extend its lifetime to more than 1,000 cycles, but Cui said he finds it encouraging that improving the usually overlooked binder material produced such dramatic benefits.

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

Stable cycling of lithium sulfide cathodes through strong affinity with a bifunctional binder by Zhi Wei Seh, Qianfan Zhang, Weiyang Li, Guangyuan Zheng, Hongbin Yaoa, and Yi Cui. Chem. Sci., 2013,4, 3673-3677 DOI: 10.1039/C3SC51476E First published online 11 Jul 2013

There’s a note on the website stating the article is free but the instructions for accessing the article are confusing seeming to suggest you need a subscription of some sort or you need to register for the site.

I have written about Yi Cui’s work with lithium-ion batteries before including this Jan. 9, 2013 posting, How is an eggshell like a lithium-ion battery?, which also features a news release by Mike Ross.

How is an eggshell like a lithium-ion battery?

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How is an eggshell like a lithium-ion battery? It’s all about the yolk. Some days I can’t resist the urge for some wordplay, even if it isn’t the best fit, and the Jan. 9, 2013 news item by Mike Ross on phys.org proved irresistible,

SLAC [Stanford National Accelerator Laboratory] and Stanford [University] scientists have set a world record for energy storage, using a clever “yolk-shell” design to store five times more energy in the sulfur cathode of a rechargeable lithium-ion battery than is possible with today’s commercial technology. The cathode also maintained a high level of performance after 1,000 charge/discharge cycles, paving the way for new generations of lighter, longer-lasting batteries for use in portable electronics and electric vehicles.

The study has been published in Nature Communications where this explanatory image amongst others can be viewed,

[downloaded from Nature Communications: http://www.nature.com/ncomms/journal/v4/n1/full/ncomms2327.html]

[downloaded from Nature Communications: http://www.nature.com/ncomms/journal/v4/n1/full/ncomms2327.html]

You can find out more about the research here,

Sulphur–TiO2 yolk–shell nanoarchitecture with internal void space for long-cycle lithium–sulphur batteries by Zhi Wei Seh, Weiyang Li, Judy J. Cha,    Guangyuan Zheng, Yuan Yang, Matthew T. McDowell, Po-Chun Hsu & Yi Cui in Nature Communications 4, Article number: 1331 doi:10.1038/ncomms2327

The Jan. 8, 2013 SLAC news release, which originated the news item, provides more details about the lithium-ion batteries in general and this attempt to improve their energy storage capacity,

Lithium-ion batteries work by moving lithium ions back and forth between two electrodes, the cathode and anode. Charging the battery forces the ions and electrons into the anode, creating an electrical potential that can power a wide range of devices. Discharging the battery – using it to do work – moves the ions and electrons to the cathode.

Today’s lithium-ion batteries typically retain about 80 percent of their initial capacity after 500 charge/discharge cycles.

For some 20 years, researchers have known that sulfur could theoretically store more lithium ions, and thus much more energy, than today’s cathode materials…

Cui’s innovation is a cathode made of nanoparticles, each a tiny sulfur nugget surrounded by a hard shell of porous titanium-oxide, like an egg yolk in an eggshell. Between the yolk and shell, where the egg white would be, is an empty space into which the sulfur can expand. During discharging, lithium ions pass through the shell and bind to the sulfur, which expands to fill the void but not so much as to break the shell. The shell, meanwhile, protects the sulfur-lithium intermediate compound from electrolyte solvent that would dissolve it.

Each cathode particle is only 800 nanometers (billionths of a meter) in diameter, about one-hundredth the diameter of a human hair.

…

“After 1,000 charge/discharge cycles, our yolk-shell sulfur cathode had retained about 70 percent of its energy-storage capacity. This is the highest performing sulfur cathode in the world, as far as we know,” he [Cui] said. “Even without optimizing the design, this cathode cycle life is already on par with commercial performance. This is a very important achievement for the future of rechargeable batteries.”

…

Over the past seven years, Cui’s group has demonstrated a succession of increasingly capable anodes that use silicon rather than carbon because it can store up to 10 times more charge per weight. Their most recent anode also has a yolk-shell design that retains its energy-storage capacity over 1,000 charge/discharge cycles.

The group’s next step is to combine the yolk-shell sulfur cathode with a yolk-shell silicon anode to see if together they produce a high-energy, long-lasting battery.

I have posted a number of recent pieces about lithium-ion (li-ion) batteries including a Dec. 12, 2012 piece about using the Madder plant to develop a greener li-ion battery, a Dec. 10, 2012 piece about the break-up of 123 Systems, a manufacturer of li-ion batteries, and a Nov. 27, 2012 piece about a project in Québec to combine lithium iron phospate with graphene for improved li-ion batteries.

Printing jello and conducting electricity

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The July 4, 2012 news item on ScienceDaily about a gel that behaves like biological tissue but conducts electricity is another one of those pieces of research which illustrate the idea that the boundary between the behaviour of biological and nonbiological materials is wavering,

The material, created by Stanford chemical engineering Associate Professor Zhenan Bao, materials science and engineering Associate Professor Yi Cui and members of their labs, is a kind of conducting hydrogel — a jelly that feels and behaves like biological tissues, but conducts electricity like a metal or semiconductor.

That combination of characteristics holds enormous promise for biological sensors and futuristic energy storage devices, but has proven difficult to manufacture until now.

The ScienceDaily news item originated in a June 27, 2012 article written by Max McClure for the (University of) Stanford Report,

Bao and Cui made the gel by binding long chains of the organic compound aniline together with phytic acid, found naturally in plant tissues. The acid is able to grab up to six polymer chains at once, making for an extensively cross-linked network.

“There are already commercially available conducting polymers,” said Bao, “but they all form a uniform film without any nanostructures.”

In contrast, the new gel’s cross-linking makes for a complex, sponge-like structure.  The hydrogel is marked with innumerable tiny pores that expand the gel’s surface area, increasing the amount of charge it can hold, its ability to sense chemicals, and the rapidity of its electrical response.

Still, the gel can be easily manipulated. Because the material doesn’t solidify until the last step of its synthesis, it can be printed or sprayed as a liquid and turned into a gel after it’s already in place – meaning that manufacturers should be able to construct intricately patterned electrodes at low cost.

Here’s more about the electrical conductance properties from the McClure article,

The material’s unusual structure also gives the gel what Cui referred to as “remarkable electronic properties.”

Most hydrogels are tied together by a large number of insulating molecules, reducing the material’s overall ability to pass electrical current. But phytic acid is a “small-molecule dopant” – meaning that when it links polymer chains, it also lends them charge. This effect makes the hydrogel highly conductive.

The gel’s conductance is “among the best you can get through this kind of process,” said Cui. Its capacity to hold charge is very high, and its response to applied charge is unusually fast.

The substance’s similarity to biological tissues, its large surface area and its electrical capabilities make it well suited for allowing biological systems to communicate with technological hardware.

The researchers envision it being used in everything from medical probes and laboratory biological sensors to biofuel cells and high-energy density capacitors.

“And all it’s made of are commercially available ingredients thrown into a water solution,” said Bao.

The July 4, 2012 ScienceDaily news item provided this citation for the paper,

L. Pan, G. Yu, D. Zhai, H. R. Lee, W. Zhao, N. Liu, H. Wang, B. C.- K. Tee, Y. Shi, Y. Cui, Z. Bao. Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity. Proceedings of the National Academy of Sciences, 2012; 109 (24): 9287 DOI: 10.1073/pnas.1202636109

A whispering gallery for light not sound

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Whispering galleries are always popular with all ages. I know that because I can never get enough time in them as I jostle with seniors, children, young adults, etc. For most humans, the magic of having someone across from you on the other side of the room sound as if they’re beside you whispering in your ear is ever fresh.

It’s the roundness of the space, which gives it that special acoustic quality. Taking their inspiration from whispering galleries, engineers at Stanford University have created hollow nanoshell ‘whispering galleries’ for light rather than sound. From the Feb. 7, 2012 news item on Nanowerk,

The engineers call their spheres nanoshells. Producing the shells takes a bit of engineering magic. The researchers first create tiny balls of silica — the same stuff glass is made of — and coat them with a layer of silicon. They then etch away the glass center using hydrofluoric acid that does not affect the silicon, leaving behind the all-important light-sensitive shell. These shells form optical whispering galleries that capture and recirculate the light.

“The light gets trapped inside the nanoshells,” said Yi Cui, associate professor of materials science engineering at Stanford and a senior author of the paper. “It circulates round and round rather than passing through and this is very desirable for solar applications.”

The researchers estimate that light circulates around the circumference of the shells a few times during which energy from the light gets absorbed gradually by the silicon. The longer they can keep the light in the material, the better the absorption will be.

“This is a new approach to broadband light absorption. The use of whispering-gallery resonant modes inside nanoshells is very exciting,” said Yan Yao, a post-doctoral researcher in the Cui Lab and a co-lead author of the paper. “It not only can lead to better solar cells, but it can be applied in other areas where efficient light absorption is important, such as solar fuels and photodetectors.”

The nanoshells look like this,

A scanning electron microscope (SEM) image of a single layer of nanocrystalline-silicon shells. The hollow shell structure improves light absorption while reducing the cost and weight of the device. Image: Yan Yao

Andrew Meyers’ Feb. 2012 article for Stanford University’s School of Engineering notes that improved light absorption isn’t the only advantage to this ‘whispering-gallery resonant mode’ technique,

Having demonstrated improved absorption, the engineers went on to show how their clever structure will pay dividends beyond the mere trapping of light.

First, nanoshells can be made quickly. “A micron-thick flat film of solid nanocrystalline-silicon can take a few hours to deposit, while nanoshells achieving similar light absorption take just minutes,” said Yan.

The nanoshell structure likewise uses substantially less material, one-twentieth that of solid nanocrystalline-silicon.

“A twentieth of the material, of course, costs one-twentieth and weighs one-twentieth what a solid layer does,” said Jie. “This might allow us to cost effectively produce better-performing solar cells of rare or expensive materials.”

“The solar film in our paper is made of relatively abundant silicon, but down the road, the reduction in materials afforded by nanoshells could prove important to scaling up the manufacturing of many types of thin film cells, such as those which use rarer materials like tellurium and indium” said Vijay Narasimhan, a doctoral candidate in the Cui Lab and co-author of the paper.

Finally, the nanoshells are relatively indifferent to the angle of incoming light and the layers are thin enough that they can bend and twist without damage. These factors might open up an array of new applications in situations where achieving optimal incoming angle of the sun is not always possible. Imagine solar sails on the high seas or photovoltaic clothing for mountain climbing.

The researchers’ paper was published in Nature Communications and the authors include: Shanhui Fan, a professor of electrical engineering, Yi Cui, associate professor of materials science engineering, Yan Yao, a post-doctoral researcher in the Cui Lab, Vijay Narasimhan, a doctoral candidate in the Cui Lab, and Jie Yao, a post-doctoral researcher in the Cui Lab.

Australian government makes an unexpected nano announcement; San Diego, the Olympics of Science, and the AAAS; Manitoba high school student discusses copyright

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Late last week I wrote about a new report, Nanotechnology in Australia: Trends, Applications and Collaborative Opportunities, that was supposed to be launched today. The news article which originated the story was by Cheryl Jones of The Australian, who noted,

THE number of Australian companies in a nanotechnology market likely to be worth trillions of dollars within a decade has plummeted, according to an Australian Academy of Science report.

Federal government reports previously put at about 80 the number of companies engaged in the technology underlying a burgeoning global market.

But now there are only 55 to 60, say nanotechnology experts cited in the academy report, to be released next week.

Little work has moved from the benchtop to the market, the report says, and one obstacle to commercialisation is “often dysfunctional” university intellectual property services.

I checked and this item from the Government of Australia was announced instead (from the Azo Materials site),

The Rudd Government is introducing a comprehensive national framework to guide the safe development of new technologies such as nanotechnology and biotechnology as part of a $38.2 million National Enabling Technologies Strategy released today.

“Technologies like nanotechnology and biotechnology have enormous potential, but we can only realise that potential with the community’s support,” said Innovation Minister, Senator Kim Carr.

“Health, safety and environmental protection are paramount for the Government. This strategy is about ensuring we meet the highest standards while at the same time maximising opportunities to develop these cutting-edge technologies.

I’m not sure what happened to the report but this announcement was a bit of a surprise. Given the material cited in Jones’ story, I would have expected the government to pull back rather than invest more heavily. It seems the government has recognized the barriers noted in the report (which has yet to be released or even seen by anyone other than Cheryl Jones [see my posting here] ETA: my apologies to Ms. Jones, I did find the report days later here at a location I failed to check, for penance I will leave my original wrong-headed and now embarrassing comment) and decided to address the issues head on.

Meanwhile, the ‘Olympics of Science’ is finishing today in San Diego (Feb. 18-22, 2010), the 176th annual meeting of the American Association for the Advancement of Science (AAAS). From the AAAS site,

The 2010 AAAS Annual Meeting is coming to San Diego for the first time, bringing cutting-edge research and a host of free events for the public in its role as the United States’ largest general scientific conference.

Described in The Times Higher Education Supplement as “the Olympics of science conferences,” the Annual Meeting has long been known as the premier multidisciplinary science gathering in the United States. This year, it will continue its evolution to a prime international affair: When the 176th meeting of the society convenes from 18-22 February, scientists, journalists, and educators from more than 50 nations will be there.

Under the banner “Bridging Science and Society,” top researchers will discuss their findings in the context of global challenges in the environment, economy, health, and education. Attendees can explore research in the neurosciences, energy, astrobiology, public health, and environmental change, and learn how these advances directly affect courtroom trials, care for the elderly, sustainable cities, border security, and other public concerns.

As part of an unprecedented effort to share the excitement of scientific discovery with the public, AAAS’s Family Science Days and other free events offer a chance at hands-on learning for students of all ages.

I mention it not just because I’m currently experiencing Vancouver’s Winter Olympics but because, in 2012, the AAAS  will be hosting its annual meeting in Vancouver.  To get a better idea of what this means, I’ve excerpted parts of a story by Maggie Koerth-Baker on Boing, Boing about attending some of the presentations at the AAAS 2010 San Diego Meeting. First an excerpt from a nanotechnology presentation,

[David] Cahill [University of Illinois] is part of a team working to improve thermal insulation with nanotechnology. His goal: Create some kind of new material that will disrupt the transfer of heat energy between two objects. Getting it right would have big implications. For instance, we could drastically improve our ability to capture the waste heat from electrical generation and put it to use in other ways.One possible solution is silicon nanowires. These structures are normally baby-butt smooth, but as you make their surfaces more and more rough, the nanowires conduct less and less thermal energy. Right now, it’s not exactly clear why that trick works. But understanding it could put Cahill’s team on the right path.

He’s not the only one taking energy technology nano. Another researcher on the same panel, Yi Cui, Ph.D., of Stanford, is applying nanostructures to energy storage, in hopes of developing smaller batteries that can hold more power.

In fact, according to Cui, nanotech is absolutely essential to any future progress with batteries. Storage capacity for size has plateaued, he explained. To go further, we have to start making electrodes out of completely different—and probably completely new—materials.

Note: I’ve mentioned Cui and his work at Stanford University here. More from Koerth-Baker, this time it’s from a science history presentation on measurements and averages,

Before that [1761], obviously, scientists still made mistakes. Multiple measurements or experiments still yielded varying results. But they dealt with the variation in a very different way—they picked the answer they thought represented their best work.

To modern ears, that sounds like cheating—”You just randomly decided on the number you liked best? That’s science?” But, at the time, it was perfectly logical. Historically, scientists viewed themselves as craftsmen,[Jeff]  Buchwald said. If you were building a piece of fine furniture, you wouldn’t make a bunch and pick the average to display. You’d choose the finished version that was the best, and best displayed your woodworking skill.

Intriguing, eh? If you want to find out who introduced the concept of averaging scientific measurements and why he was too embarrassed to publish this in his first research, do read Koerth-Baker’s piece.

For my last bit, I’m back on the copyright trail and thanks to Techdirt for alerting me to this essay on file-sharing and morality written by a grade 12 student at Balmoral Hall School (all girls) in Winnipeg,Manitoba. Kamal Dhillon won the 2010 Glassen Ethics competition,

This year’s essay topic was: “Is it OK to download music, movies and games without paying?” There were about 80 entries from high schools in Winnipeg and across the province. The contest, held annually since 2007, is jointly sponsored by The Centre for Professional and Applied Ethics and The Department of Philosophy at the University of Manitoba. The winner receives $1,000. The Winnipeg Free Press publishes the winning essay.

From the Winnipeg Free Press (Feb.13, 2010 edition), an excerpt from Dhillon’s essay,

MILLIONS of people, mostly but not all young, engage in file sharing.

The multinational corporations who make and sell the material are not happy with this development. Their profits are threatened and they, in turn, are threatening to sue, for huge amounts of money, individuals who engage in file sharing.

I support the act of file sharing and argue that the free sharing of these forms of intellectual property would likely produce, overall, more good than harm for society.

It’s a thoughtful piece and well worth reading.

Participatory science; wearable batteries; radio interview with Andrew Maynard; shadow science ministers in Canada’s political parties

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Ordinary people (nonscientists like me) have a long tradition of participating in scientific research in areas such as astronomy and ornithology (bird watching). A local example is the eagle count which takes place at Brackendale every year. (Aside: The 2010 count has already taken place but it’s still possible to attend festival events which are now part of the Brackendale eagle count experience.)

Someone whose science interests may be more esoteric can have trouble finding opportunities to pursue their interests. Thanks to the Science Cheerleader there is a new online resource to help you find a project. From the Science Cheerleader blog,

Hot diggity-DOG! After years in the making, my partner, Michael Gold, and I–with generous support from Science House–have officially unveiled the beta version (that means this is still a work-in-progress) of ScienceForCitizens.net . Science journalist, Carl Zimmer, who frequently writes for Discover and Time Magazine, said “It’s like Amazon.com for all sorts of possibilities for doing cool citizen science”. We’ll take that

And thanks to the Pasco Phronesis blog for the info. about the Science Cheerleader.

For an abrupt change of pace: Yes, you could be wearing your batteries at some point in the future. Scientists at Stanford University (CA) have found a way to easily and inexpensively turn cotton or polyester fibres into batteries or, as they call it, wearable energy textiles or e-textiles. From the news item on BBC News,

“Wearable electronics represent a developing new class of materials… which allow for many applications and designs previously impossible with traditional electronics technologies,” the authors [of the study published in ACS Nano Letters] wrote.

A number of research efforts in recent years have shown the possibility of electronics that can be built on flexible and even transparent surfaces – leading to the often-touted “roll-up display”.

However, the integration of electronics into textiles has presented different challenges, in particular developing approaches that work with ordinary fabrics.

Now, Yi Cui and his team at Stanford University in the US has shown that their “ink” made of carbon nanotubes – cylinders of carbon just billionths of a metre across – can serve as a dye that can simply and cheaply turn a t-shirt into an “e-shirt”.

I’ve taken a look at the research paper which, as these things go, is pretty readable. Bravo to the American Chemical Society (ACS) for not placing the material behind a paywall. The article, Stretchable, Porous and Conductive Energy Textiles,  published in the ACS journal Nano Letters is here.

I had the pleasure of listening to a radio interview on Whyy Radio conducted by Marty Moss-Coane where she interviewed Dr. Andrew Maynard, Chief Science Advisor for the Project on Emerging Nanotechnolgies. The interview (approximately 50 mins.)  titled, The Science and Safety of Nanotechnology, is available for listening here. Moss-Coane was well-prepared, asked good questions, and had listeners call in with their own questions. Dr. Andrew Maynard was, as always, very likable and interesting.

After my recent posting on science policy in Canada and the four major political parties, I thought I’d check out the various shadow science ministers or critics. Here’s what I found,

Gary Goodyear, Conservative, Minister of State (Science and Technology)

Jim Maloway, NDP, Science and Technology [portfolio]

Frances Coates, Green Party, shadow minister Science and Technology

Marc Garneau, Liberal Party, Industry, Science and Technology critic

I have looked at all their websites and Garneau seems the most interested in science and technology issues. Given that he’s a former astronaut and is an engineer, one might expect that he would have a major interest in the subject. He’s written a paper on the subject (thanks to the folks at The Black Hole for finding it). If you go here and either read or scroll to the bottom, you will find a link to his paper. He also has a poll on his website, What is the importance of science and technology to create the jobs for tomorrow? You can go here to answer the question. As for the others, Goodyear lists a series of announcements in news releases as accomplishments which makes identifying his actual accomplishments difficult. Jim Maloway does not mention science on his website and Frances Coates posted a few times on her blog in 2008 but made no mention of science.