Category Archives: clothing

Imprinting fibres at the nanometric scale

Switzerland’s École Polytechnique Fédérale de Lausanne (EPFL) announces a discovery in a Jan. 24, 2017 press release (also on EurkeAlert),

Researchers at EPFL have come up with a way of imprinting nanometric patterns on the inside and outside of polymer fibers. These fibers could prove useful in guiding nerve regeneration and producing optical effects, for example, as well as in eventually creating artificial tissue and smart bandages.

Researchers at EPFL’s Laboratory of Photonic Materials and Fibre Devices, which is run by Fabien Sorin, have come up with a simple and innovative technique for drawing or imprinting complex, nanometric patterns on hollow polymer fibers. Their work has been published in Advanced Functional Materials.

The potential applications of this breakthrough are numerous. The imprinted designs could be used to impart certain optical effects on a fiber or make it water-resistant. They could also guide stem-cell growth in textured fiber channels or be used to break down the fiber at a specific location and point in time in order to release drugs as part of a smart bandage.

Stretching the fiber like molten plastic

To make their nanometric imprints, the researchers began with a technique called thermal drawing, which is the technique used to fabricate optical fibers. Thermal drawing involves engraving or imprinting millimeter-sized patterns on a preform, which is a macroscopic version of the target fiber. The imprinted preform is heated to change its viscosity, stretched like molten plastic into a long, thin fiber and then allowed to harden again. Stretching causes the pattern to shrink while maintaining its proportions and position. Yet this method has a major shortcoming: the pattern does not remain intact below the micrometer scale. “When the fiber is stretched, the surface tension of the structured polymer causes the pattern to deform and even disappear below a certain size, around several microns,” said Sorin.

To avoid this problem, the EPFL researchers came up with the idea of sandwiching the imprinted preform in a sacrificial polymer [emphasis mine]. This polymer protects the pattern during stretching by reducing the surface tension. It is discarded once the stretching is complete. Thanks to this trick, the researchers are able to apply tiny and highly complex patterns to various types of fibers. “We have achieved 300-nanometer patterns, but we could easily make them as small as several tens of nanometers,” said Sorin. This is the first time that such minute and highly complex patterns have been imprinted on flexible fiber on a very large scale. “This technique enables to achieve textures with feature sizes two order of magnitude smaller than previously reported,” said Sorin. “It could be applied to kilometers of fibers at a highly reasonable cost.”

To highlight potential applications of their achievement, the researchers teamed up with the Bertarelli Foundation Chair in Neuroprosthetic Technology, led by Stéphanie Lacour. Working in vitro, they were able to use their fibers to guide neurites from a spinal ganglion (on the spinal nerve). This was an encouraging step toward using these fibers to help nerves regenerate or to create artificial tissue.

This development could have implications in many other fields besides biology. “Fibers that are rendered water-resistant by the pattern could be used to make clothes. Or we could give the fibers special optical effects for design or detection purposes. There is also much to be done with the many new microfluidic systems out there,” said Sorin. The next step for the researchers will be to join forces with other EPFL labs on initiatives such as studying in vivo nerve regeneration. All this, thanks to the wonder of imprinted polymer fibers.

I like the term “sacrificial polymer.”

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

Controlled Sub-Micrometer Hierarchical Textures Engineered in Polymeric Fibers and Microchannels via Thermal Drawing by Tung Nguyen-Dang, Alba C. de Luca, Wei Yan, Yunpeng Qu, Alexis G. Page, Marco Volpi, Tapajyoti Das Gupta, Stéphanie P. Lacour, and Fabien Sorin. Advanced Functional Materials DOI: 10.1002/adfm.201605935 Version of Record online: 24 JAN 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Little black graphene dress

Graphene Dress. Courtesy: intu

I don’t think there are many women who can carry off this garment. Of course that’s not the point as the dress is designed to show off its technical capabilities. A Jan. 31, 2017 news item on Nanowerk announces the little black graphene dress (lbgd?),

Science and fashion have been brought together to create the world’s most technically advanced dress, the intu Little Black Graphene Dress.

The new prototype garment showcases the future uses of the revolutionary, Nobel Prize winning material graphene and incorporating it into fashion for the first time, in the ultimate wearable tech statement garment.

A Jan. 25, 2017 National Graphene Institute at University of Manchester press release, which originated the news item, expands on the theme,

The project between intu Trafford Centre, renowned wearable tech company Cute Circuit which has made dresses for the likes of Katy Perry and Nicole Scherzinger and the National Graphene Institute at The University of Manchester, uses graphene in a number of innovative ways to create the world’s most high tech LBD – highlighting the material’s incredible properties.

The dress is complete with a graphene sensor which captures the rate in which the wearer is breathing via a contracting graphene band around the models waist, the micro LED which is featured across the bust on translucent conductive graphene responds to the sensor making the LED flash and changing colour depending on breathing rate. It marks a major step in the future uses of graphene in fashion where it is hoped the highly conductive transparent material could be used to create designs which act as screens showcasing digital imagery which could be programmed to change and updated by the wearer meaning one garment could be in any colour hue or design.

The 3D printed graphene filament shows the intricate structural detail of graphene in raised diamond shaped patterns and showcases graphene’s unrivalled conductivity with flashing LED lights.

The high tech LBD can be controlled by The Q app created by Cute Circuit to change the way the garment illuminates.

The dress was created by the Manchester shopping centre to celebrate Manchester’s crown as the European City of Science. The dress will then be on display at intu Trafford Centre, it will then be available for museums and galleries to loan for fashion displays.

Richard Paxton, general manager at intu Trafford Centre said: “We have a real passion for fashion and fashion firsts, this dress is a celebration of Manchester, its amazing love for innovation and textiles, showcasing this new wonder material in a truly unique and exciting way. It really is the world’s most high-tech dress featuring the most advanced super-material and something intu is very proud to have created in collaboration with Cute Circuit and the National Graphene Institute. Hopefully this project inspires more people to experiment with graphene and its wide range of uses.”

Francesca Rosella, Chief Creative Director for Cute Circuit said: “This was such an exciting project for us to get involved in, graphene has never been used in the fashion industry and being the first to use it was a real honour allowing us to have a lot of fun creating the stunning intu Little Black Graphene Dress, and showcasing graphene’s amazing properties.”

Dr Paul Wiper, Research Associate, National Graphene Institute said: “This is a fantastic project, graphene is still very much at its infancy for real-world applications and showcasing its amazing properties through the forum of fashion is very exciting. The dress is truly a one of a kind and shows what creativity, imagination and a desire to innovate can create using graphene and related two-dimensional materials.”

The dress is modelled by Britain’s Next Top Model finalist Bethan Sowerby who is from Manchester and used to work at intu Trafford Centre’s Top Shop.

Probably not coming soon to a store near you.

Drip dry housing

This piece on new construction materials does have a nanotechnology aspect although it’s not made clear exactly how nanotechnology plays a role.

From a Dec. 28, 2016 news item on phys.org (Note: A link has been removed),

The construction industry is preparing to use textiles from the clothing and footwear industries. Gore-Tex-like membranes, which are usually found in weather-proof jackets and trekking shoes, are now being studied to build breathable, water-resistant walls. Tyvek is one such synthetic textile being used as a “raincoat” for homes.

You can find out more about Tyvek here.on the Dupont website.

A Dec. 21, 2016 press release by Chiara Cecchi for Youris ((European Research Media Center), which originated the news item, proceeds with more about textile-type construction materials,

Camping tents, which have been used for ages to protect against wind, ultra-violet rays and rain, have also inspired the modern construction industry, or “buildtech sector”. This new field of research focuses on the different fibres (animal-based such as wool or silk, plant-based such as linen and cotton and synthetic such as polyester and rayon) in order to develop technical or high-performance materials, thus improving the quality of construction, especially for buildings, dams, bridges, tunnels and roads. This is due to the fibres’ mechanical properties, such as lightness, strength, and also resistance to many factors like creep, deterioration by chemicals and pollutants in the air or rain.

“Textiles play an important role in the modernisation of infrastructure and in sustainable buildings”, explains Andrea Bassi, professor at the Department of Civil and Environmental Engineering (DICA), Politecnico of Milan, “Nylon and fiberglass are mixed with traditional fibres to control thermal and acoustic insulation in walls, façades and roofs. Technological innovation in materials, which includes nanotechnologies [emphasis mine] combined with traditional textiles used in clothes, enables buildings and other constructions to be designed using textiles containing steel polyvinyl chloride (PVC) or ethylene tetrafluoroethylene (ETFE). This gives the materials new antibacterial, antifungal and antimycotic properties in addition to being antistatic, sound-absorbing and water-resistant”.

Rooflys is another example. In this case, coated black woven textiles are placed under the roof to protect roof insulation from mould. These building textiles have also been tested for fire resistance, nail sealability, water and vapour impermeability, wind and UV resistance.

Photo: Production line at the co-operative enterprise CAVAC Biomatériaux, France. Natural fibres processed into a continuous mat (biofib) – Martin Ansell, BRE CICM, University of Bath, UK

In Spain three researchers from the Technical University of Madrid (UPM) have developed a new panel made with textile waste. They claim that it can significantly enhance both the thermal and acoustic conditions of buildings, while reducing greenhouse gas emissions and the energy impact associated with the development of construction materials.

Besides textiles, innovative natural fibre composite materials are a parallel field of the research on insulators that can preserve indoor air quality. These bio-based materials, such as straw and hemp, can reduce the incidence of mould growth because they breathe. The breathability of materials refers to their ability to absorb and desorb moisture naturally”, says expert Finlay White from Modcell, who contributed to the construction of what they claim are the world’s first commercially available straw houses, “For example, highly insulated buildings with poor ventilation can build-up high levels of moisture in the air. If the moisture meets a cool surface it will condensate and producing mould, unless it is managed. Bio-based materials have the means to absorb moisture so that the risk of condensation is reduced, preventing the potential for mould growth”.

The Bristol-based green technology firm [Modcell] is collaborating with the European Isobio project, which is testing bio-based insulators which perform 20% better than conventional materials. “This would lead to a 5% total energy reduction over the lifecycle of a building”, explains Martin Ansell, from BRE Centre for Innovative Construction Materials (BRE CICM), University of Bath, UK, another partner of the project.

“Costs would also be reduced. We are evaluating the thermal and hygroscopic properties of a range of plant-derived by-products including hemp, jute, rape and straw fibres plus corn cob residues. Advanced sol-gel coatings are being deposited on these fibres to optimise these properties in order to produce highly insulating and breathable construction materials”, Ansell concludes.

You can find Modcell here.

Here’s another image, which I believe is a closeup of the processed fibre shown in the above,

Production line at the co-operative enterprise CAVAC Biomatériaux, France. Natural fibres processed into a continuous mat (biofib) – Martin Ansell, BRE CICM, University of Bath, UK [Note: This caption appears to be a copy of the caption for the previous image]

Fashion Week Netherlands and a conversation about nanotextiles

Marjolein Lammerts van Bueren has written up an interview with the principals of Nanonow consulting agency, in a Dec. 15, 2016 article for Amsterdam Fashion Week, where they focus on nanotextiles (Note: Links have been removed),

Strong, sustainable textiles created by combining chemical recycling and nanotechnology – for Vincent Franken and Roel Boekel, their nanotechstiles are there already. With their consulting firm, Nanonow, the two men help companies in a range of industries innovate in the field of nanotechnology. And yes, you guessed it, the fashion industry, too, is finding ways to use the technology to its advantage. Fashionweek.nl sat down with Franken to talk about textiles on a nano scale.

How did you come up with the idea for Nanonow?

“I studied Science, Business & Innovations at the VU in Amsterdam. That’s a beta course that focuses on new technologies and how you can bring them to the market, and I specialised in nanotechnology within that. Because of the many – still untapped – opportunities and applications there are for nanotechnology, I started Nanonow with Roel Boekel after I graduated in 2014. We’re a consulting firm helping companies that still don’t really know how they can make use of nanotechnology, which can be used for a whole lot of things.”

Like the textile industry?

“Exactly. Over the last few years, we’ve done research into several different industries, like the waste and recycling industry. Six months ago we started looking at the textile industry, via Frankenhuis, an international textile recycler. When you throw your clothes in the recycling bin, a portion of them are sold on and a portion are recycled, or downcycled, as I call it. They pull the textiles apart, and those fibres – so the threads – are sold and repurposed into things like insulation. Roel and I thought that was a shame, because you’re deconstructing clothes that have often barely been worn just to make a low-value product out of them.”

So you’ve developed an alternative, Nanotechstiles. Tell us about it!

“We actually wanted to make new clothes from the deconstructed clothes. This is already happening via mechanical recycling, where you produce new clothes by reweaving the old textile fibres. But for me, the Holy Grail we’re looking for – I’m a tech guy after all – is the molecules inside the fibres.”

“First, we don’t want to use the existing thread, but instead we want to pull the thread apart completely then put it back together again. This is called chemical recycling and it’s already happening today. You can remove the cellulose fibres from cotton then put them back together to form viscose or lyocell. The downside of that is that the process is pretty expensive and the quality isn’t always that good.”

“Then you also have nanotechnologies, an area that’s developing rapidly and is already being used to strengthen textiles, which makes them last longer. But there are more options for making textiles no-iron, antibacterial – so that it doesn’t start to smell as quickly – or stain resistant. You can also integrate energy-saving electronics into them, or make them water resistant, as you saw last year on Valerio Zeno and Dennis Storm’s BNN TV programme, Proefkonijnen.”

“When you use nanotechnology to make materials smaller, you transform them, as it were, giving them completely different characteristics. So the fact that you can transform materials means that you can also do this with the threads themselves. We believe that when you combine chemical recycling with nanotechnology, what you get is the perfect thread. We call them nanotechstiles, and in the end, they lead to higher quality clothes that are sustainable, as well.”

“The fact that you can transform materials means that you can also do this with the threads themselves”

How far along are you in the research for nanotechstiles?

“We won the TKI Dinalog Take Off in the logistics sector last year with our nanotechstiles idea. That’s a prize for young talent with innovative ideas for economics and logistics. Since then, we’ve been trying to make the concept more concrete. Which recycling methods can we combine with which nanotechnologies? We’re already pretty far along in that research process, but there hasn’t been any clothing produced from it as yet. We’re focusing on cotton because it makes up the largest proportion of waste. At the moment, we’re in talks with the Institut für Textiltechnik at the University of Aken about how we can produce clothes from our nanotechstiles.

Have you also discovered some pitfalls as part of your research?

“The frustrating thing about nanotechnology is that the more you know about it, the less you can do with it. A lot of options are eliminated during the research process. I’ll give you an example. You want to make clothes that don’t smell as quickly? Well, on paper we know that silver kills 99.9% of bacteria, though we haven’t tested it. So then that leaves you with 0.1%, and that percentage can grow exponentially by using the nutrients from other bacteria. So the material in the clothing itself is safe, but what if a few particles come loose in the wash and get into the drinking water? What happens then? A lot of potential options are eliminated as you go through a process like that because they can be dangerous.”

What are the downsides and how can you guarantee that a design is safe?

“A tremendous amount of nanotechnologies are still in the research phase, so they’re too expensive to develop. We’d like to be using some of them now, but it turns out that there are still too many uncertainties to realistically put them into use. It’s essential to apply the principles of safety by design, only using nanotechnologies where the safety concerns have been well thought out. That’s something we’ve been in touch with the Rijksinstituut voor Volksgezondheid en Milieu (Royal Institute for Public Health and the Environment, RIVM) about. We take safety and the environment into account at every step in the production process for nanotechstiles.”

What the biggest challenge to your concept?

“We already know how certain nanotechnologies respond to cotton, but the biggest challenge is to figure out how they respond to recycled fabrics. You have to remember that nanotechnology isn’t just one thing. You can apply it to any material, which gives you thousands of possibilities. The question is, which one do you think is the most important? For example, you can add carbon nanotubes to make a fabric stronger, but then you’d be paying thousands of euros for a single shirt, and no one wants that.”

What’s the next step?

“Right now, we’re trying to get a sort of crowdfunding campaign started amongst businesses. We’re hoping to build relationships with companies like IKEA, who want to use our sustainable and stain-resistant textiles for things like their employee uniforms. So in addition to the subsidies, they’re helping to fund the research in that way. Based on that, we’ll eventually choose a nanotechnology that we can work up into an actual textile.”

I encourage you to read the original article with its embedded images, additional information, and links to more information.

One last comment, nanotechnology-enabled textiles are usually brand new materials so this is the first time I’ve seen a nanotechnology-based approach to recycling textiles. Bravo!

Luxury watches exploit nanocomposite materials

Who knew Dominic Purcell (actor: Prison Break, Legends of Tomorrow, etc.) is England-born and raised in Australia? You find the oddest nuggets of information when tracking down details about nanoscience and nanotechnology. In this case, it was a Nov. 29, 2016 news item about luxury watches and a nanocomposite which eventually led me to Purcell,

Founded by Swiss-born Sydneysider Christophe Hoppe, Bausele Australia bills itself as the first “Swiss-made, Australian-designed” watch company.

The name is an acronym for Beyond Australian Elements. Each watch has part of the Australian landscape embedded in its crown, or manual winding mechanism, such as red earth from the outback, beach sand or bits of opal.

But what makes the luxury watches unique is an innovative material called Bauselite developed in partnership with Flinders University’s Centre of NanoScale Science and Technology in Adelaide. An advanced ceramic nanotechnology, Bauselite is featured in Bausele’s Terra Australis watch, enabling design elements not found in its competitors.

A Nov. 10, 2016article by Myles Gough for Australia Unlimited provides more details,

NanoConnect program fosters industry partnership
Flinders University coordinates NanoConnect, a collaborative research program supported by the South Australian Government, which provides a low-risk pathway for companies to access university equipment and expertise.

It was through this program that Hoppe met nanotechnologist Professor David Lewis, and his colleagues Dr Jonathan Campbell and Dr Andrew Block.

“There were a lot of high IQs around that table, except for me,” jokes Hoppe about their first meeting.

After some preliminary discussions, the Flinders team set about researching the luxury watch industry and identified several areas for innovation. The one they focused on with Hoppe was around the manufacture of casings.

Apart from the face, the case is the most prominent feature on a watch head: it needs to be visually appealing but also lightweight and strong, says Hoppe, who is also Bausele’s chief designer.

The researchers suggested ceramics might be suitable. Conventional ceramics require casting, where a powder slurry is injected into a mould and heated in an oven. The process is suitable for high-volume manufacturing, but the end product is often hampered by small imperfections or deformities. This can cause components to break, resulting in wasted material, time and money. It can also make the material incompatible with complex designs, such as those featured in the Terra Australis.

New material offers ‘competitive edge’

Using a new technique, the Flinders team invented a unique, lightweight ceramic-like material that can be produced in small batches via a non-casting process, which helps eliminate defects found in conventional ceramics. They named the high-performance material Bauselite.

“Bauselite is strong, very light and, because of the way it is made, avoids many of the traps common with conventional ceramics,” explains Professor Lewis.

The new material allows holes to be drilled more precisely, which is an important feature in watchmaking. “It means we can make bolder, more adventurous designs, which can give us a competitive advantage,” Hoppe says.

Bauselite can also be tailored to meet specific colour, shape and texture requirements. “This is a major selling point,” Hoppe says. “Watch cases usually have a shiny, stainless steel-like finish, but the Bauselite looks like a dark textured rock.”

Advanced manufacturing hub in Australia

Hoppe and the Flinders University team are currently working on the development of new materials and features.

Together they have established a joint venture company called Australian Advanced Manufacturing to manufacture bauselite.  A range of other precision watch components could be in the pipeline.

The team hopes to become a ‘centre of excellence’ for watchmaking in Australia, supplying components to international luxury watchmaking brands.

But the priority is for the advanced manufacturing hub to begin making Bausele watches onshore: “I’ve seen what Europe is good at when it comes to creating luxury goods, and what makes it really special is when people control the whole process from beginning to end,” says Hoppe. “This is what we want to do. We’ll start with one component now, but we’ll begin to manufacture others.”

Hoppe hopes the hub will be a place where students can develop similar, high-performance materials, which could find applications across a range of industries, from aerospace to medicine for bone and joint reconstructions.

Here’s Purcell (I’m pretty sure the watch he’s modeling does not feature the nanocomposite),

Courtesy: Bausele [downloaded http://www.thefashionisto.com/dominic-purcell-2016-bausele-campaign/]

Courtesy: Bausele [downloaded http://www.thefashionisto.com/dominic-purcell-2016-bausele-campaign/]

For the curious, here’s an image featuring the nanocomposite casing,

Christophe Hoppe with his new Bauselite watch casing. (Image: Flinders University/Bausele) Read more: Nanotechnology and luxury watches: an innovative partnership

Christophe Hoppe with his new Bauselite watch casing. (Image: Flinders University/Bausele)
Read more: Nanotechnology and luxury watches: an innovative partnership

As for the nanotechnology-enabled watch itself,

Terra Australis Courtesy: Bausele

Terra Australis Courtesy: Bausele

If you’re looking for a Christmas or Hanukkah or Kwanzaa gift  and don’t mind being a bit late, here’s the Bausele website.

 

Solar-powered clothing

This research comes from the University of Central Florida (US) and includes a pop culture reference to the movie “Back to the Future.”  From a Nov. 14, 2016 news item on phys.org,

Marty McFly’s self-lacing Nikes in Back to the Future Part II inspired a UCF scientist who has developed filaments that harvest and store the sun’s energy—and can be woven into textiles.

The breakthrough would essentially turn jackets and other clothing into wearable, solar-powered batteries that never need to be plugged in. It could one day revolutionize wearable technology, helping everyone from soldiers who now carry heavy loads of batteries to a texting-addicted teen who could charge his smartphone by simply slipping it in a pocket.

A Nov. 14, 2016 University of Central Florida news release (also on EurekAlert) by Mark Schlueb, which originated the news item, expands on the theme,

“That movie was the motivation,” Associate Professor Jayan Thomas, a nanotechnology scientist at the University of Central Florida’s NanoScience Technology Center, said of the film released in 1989. “If you can develop self-charging clothes or textiles, you can realize those cinematic fantasies – that’s the cool thing.”

Thomas already has been lauded for earlier ground-breaking research. Last year, he received an R&D 100 Award – given to the top inventions of the year worldwide – for his development of a cable that can not only transmit energy like a normal cable but also store energy like a battery. He’s also working on semi-transparent solar cells that can be applied to windows, allowing some light to pass through while also harvesting solar power.

His new work builds on that research.

“The idea came to me: We make energy-storage devices and we make solar cells in the labs. Why not combine these two devices together?” Thomas said.

Thomas, who holds joint appointments in the College of Optics & Photonics and the Department of Materials Science & Engineering, set out to do just that.

Taking it further, he envisioned technology that could enable wearable tech. His research team developed filaments in the form of copper ribbons that are thin, flexible and lightweight. The ribbons have a solar cell on one side and energy-storing layers on the other.

Though more comfortable with advanced nanotechnology, Thomas and his team then bought a small, tabletop loom. After another UCF scientists taught them to use it, they wove the ribbons into a square of yarn.

The proof-of-concept shows that the filaments could be laced throughout jackets or other outwear to harvest and store energy to power phones, personal health sensors and other tech gadgets. It’s an advancement that overcomes the main shortcoming of solar cells: The energy they produce must flow into the power grid or be stored in a battery that limits their portability.

“A major application could be with our military,” Thomas said. “When you think about our soldiers in Iraq or Afghanistan, they’re walking in the sun. Some of them are carrying more than 30 pounds of batteries on their bodies. It is hard for the military to deliver batteries to these soldiers in this hostile environment. A garment like this can harvest and store energy at the same time if sunlight is available.”

There are a host of other potential uses, including electric cars that could generate and store energy whenever they’re in the sun.

“That’s the future. What we’ve done is demonstrate that it can be made,” Thomas said. “It’s going to be very useful for the general public and the military and many other applications.”

The proof-of-concept shows that the filaments could be laced throughout jackets or other outwear to harvest and store energy to power phones, personal health sensors and other tech gadgets. It's an advancement that overcomes the main shortcoming of solar cells: the energy they produce must flow into the power grid or be stored in a battery that limits their portability. Credit: UCF Read more at: http://phys.org/news/2016-11-future-solar-nanotech-powered.html#jCp

The proof-of-concept shows that the filaments could be laced throughout jackets or other outwear to harvest and store energy to power phones, personal health sensors and other tech gadgets. It’s an advancement that overcomes the main shortcoming of solar cells: the energy they produce must flow into the power grid or be stored in a battery that limits their portability. Credit: UCF

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

Wearable energy-smart ribbons for synchronous energy harvest and storage by Chao Li, Md. Monirul Islam, Julian Moore, Joseph Sleppy, Caleb Morrison, Konstantin Konstantinov, Shi Xue Dou, Chait Renduchintala, & Jayan Thomas. Nature Communications 7, Article number: 13319 (2016)  doi:10.1038/ncomms13319 Published online: 11 November 2016

This paper is open access.

Dexter Johnson in a Nov. 15, 2016 posting on his blog Nanoclast on the IEEE (Institute of Electrical and Electronics Engineers) provides context for this research and, in this excerpt, more insight from the researcher,

In a telephone interview with IEEE Spectrum, Thomas did concede that at this point, the supercapacitor was not capable of storing enough energy to replace the batteries entirely, but could be used to make a hybrid battery that would certainly reduce the load a soldier carries.

Thomas added: “By combining a few sets of ribbons (2-3 ribbons) in parallel and connecting these sets (3-4) in a series, it’s possible to provide enough power to operate a radio for 10 minutes. …

For anyone interested in knowing more about how this research fits into the field of textiles that harvest energy, I recommend reading Dexter’s piece.

Textiles that clean pollution from air and water

I once read that you could tell what colour would be in style by looking at the river in Milan (Italy). It may or may not still be true in Milan but it seems that the practice of using the river for dumping the fashion industry’s wastewater is still current in at least some parts of the world according to a Nov. 10, 2016 news item on Nanowerk featuring Juan Hinestroza’s work on textiles that clear pollution,

A stark and troubling reality helped spur Juan Hinestroza to what he hopes is an important discovery and a step toward cleaner manufacturing.

Hinestroza, associate professor of fiber science and director of undergraduate studies in the College of Human Ecology [Cornell University], has been to several manufacturing facilities around the globe, and he says that there are some areas of the planet in which he could identify what color is in fashion in New York or Paris by simply looking at the color of a nearby river.

“I saw it with my own eyes; it’s very sad,” he said.

Some of these overseas facilities are dumping waste products from textile dying and other processes directly into the air and waterways, making no attempt to mitigate their product’s effect on the environment.

“There are companies that make a great effort to make things in a clean and responsible manner,” he said, “but there are others that don’t.”

Hinestroza is hopeful that a technique developed at Cornell in conjunction with former Cornell chemistry professor Will Dichtel will help industry clean up its act. The group has shown the ability to infuse cotton with a beta-cyclodextrin (BCD) polymer, which acts as a filtration device that works in both water and air.

A Nov. 10, 2016 Cornell University news release by Tom Fleischman provides more detail about the research,

Cotton fabric was functionalized by making it a participant in the polymerization process. The addition of the fiber to the reaction resulted in a unique polymer grafted to the cotton surface.

“One of the limitations of some super-absorbents is that you need to be able to put them into a substrate that can be easily manufactured,” Hinestroza said. “Fibers are perfect for that – fibers are everywhere.”

Scanning electron microscopy showed that the cotton fibers appeared unchanged after the polymerization reaction. And when tested for uptake of pollutants in water (bisphenol A) and air (styrene), the polymerized fibers showed orders of magnitude greater uptakes than that of untreated cotton fabric or commercial absorbents.

Hinestroza pointed to several positives that should make this functionalized fabric technology attractive to industry.

“We’re compatible with existing textile machinery – you wouldn’t have to do a lot of retooling,” he said. “It works on both air and water, and we proved that we can remove the compounds and reuse the fiber over and over again.”

Hinestroza said the adsorption potential of this patent-pending technique could extend to other materials, and be used for respirator masks and filtration media, explosive detection and even food packaging that would detect when the product has gone bad.

And, of course, he hopes it can play a role in a cleaner, more environmentally responsible industrial practices.

“There’s a lot of pollution generation in the manufacture of textiles,” he said. “It’s just fair that we should maybe use the same textiles to clean the mess that we make.”

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

Cotton Fabric Functionalized with a β-Cyclodextrin Polymer Captures Organic Pollutants from Contaminated Air and Water by Diego M. Alzate-Sánchez†, Brian J. Smith, Alaaeddin Alsbaiee, Juan P. Hinestroza, and William R. Dichtel. Chem. Mater., Article ASAP DOI: 10.1021/acs.chemmater.6b03624 Publication Date (Web): October 24, 2016

Copyright © 2016 American Chemical Society

This paper is open access.

One comment, I’m not sure how this solution will benefit the rivers unless they’re thinking that textile manufacturers will filter their waste water through this new fabric.

There is another researcher working on creating textiles that remove air pollution, Tony Ryan at the University of Sheffield (UK). My latest piece about his (and Helen Storey’s) work is a July 28, 2014 posting featuring a detergent that deposits onto the fabric nanoparticles that will clear air pollution. At the time, China was showing serious interest in the product.

Self-healing lithium-ion batteries for textiles

It’s easy to forget how hard we are on our textiles. We rip them, step on them, agitate them in water, splatter them with mud, and more. So, what happens when we integrate batteries and electronics into them? An Oct. 20, 2016 news item on phys.org describes one of the latest ‘textile batter technologies’,

Electronics that can be embedded in clothing are a growing trend. However, power sources remain a problem. In the journal Angewandte Chemie, scientists have now introduced thin, flexible, lithium ion batteries with self-healing properties that can be safely worn on the body. Even after completely breaking apart, the battery can grow back together without significant impact on its electrochemical properties.

wiley_selfhealinglithiumionbattery

© Wiley-VCH

An Oct. 20, 2016 Wiley Angewandte Chemie International Edition press release (also on EurekAlert), which originated the news item, describes some of the problems associated with lithium-ion batteries and this new technology designed to address them,

Existing lithium ion batteries for wearable electronics can be bent and rolled up without any problems, but can break when they are twisted too far or accidentally stepped on—which can happen often when being worn. This damage not only causes the battery to fail, it can also cause a safety problem: Flammable, toxic, or corrosive gases or liquids may leak out.

A team led by Yonggang Wang and Huisheng Peng has now developed a new family of lithium ion batteries that can overcome such accidents thanks to their amazing self-healing powers. In order for a complicated object like a battery to be made self-healing, all of its individual components must also be self-healing. The scientists from Fudan University (Shanghai, China), the Samsung Advanced Institute of Technology (South Korea), and the Samsung R&D Institute China, have now been able to accomplish this.

The electrodes in these batteries consist of layers of parallel carbon nanotubes. Between the layers, the scientists embedded the necessary lithium compounds in nanoparticle form (LiMn2O4 for one electrode, LiTi2(PO4)3 for the other). In contrast to conventional lithium ion batteries, the lithium compounds cannot leak out of the electrodes, either while in use or after a break. The thin layer electrodes are each fixed on a substrate of self-healing polymer. Between the electrodes is a novel, solvent-free electrolyte made from a cellulose-based gel with an aqueous lithium sulfate solution embedded in it. This gel electrolyte also serves as a separation layer between the electrodes.

After a break, it is only necessary to press the broken ends together for a few seconds for them to grow back together. Both the self-healing polymer and the carbon nanotubes “stick” back together perfectly. The parallel arrangement of the nanotubes allows them to come together much better than layers of disordered carbon nanotubes. The electrolyte also poses no problems. Whereas conventional electrolytes decompose immediately upon exposure to air, the new gel is stable. Free of organic solvents, it is neither flammable nor toxic, making it safe for this application.

The capacity and charging/discharging properties of a battery “armband” placed around a doll’s elbow were maintained, even after repeated break/self-healing cycles.

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

A Self-Healing Aqueous Lithium-Ion Battery by Yang Zhao, Ye Zhang, Hao Sun, Xiaoli Dong, Jingyu Cao, Lie Wang, Yifan Xu, Jing Ren, Yunil Hwang, Dr. In Hyuk Son, Dr. Xianliang Huang, Prof. Yonggang Wang, and Prof. Huisheng Peng. Angewandte Chemie International Edition DOI: 10.1002/anie.201607951 Version of Record online: 12 OCT 2016

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

This paper is behind a paywall.

Wearable microscopes

It never occurred to me that someone might want a wearable microscope but, apparently, there is a need. A Sept. 27, 2016 news item on phys.org,

UCLA [University of California at Los Angeles] researchers working with a team at Verily Life Sciences have designed a mobile microscope that can detect and monitor fluorescent biomarkers inside the skin with a high level of sensitivity, an important tool in tracking various biochemical reactions for medical diagnostics and therapy.

A Sept. 26, 2016 UCLA news release by Meghan Steele Horan, which originated the news item, describes the work in more detail,

This new system weighs less than a one-tenth of a pound, making it small and light enough for a person to wear around their bicep, among other parts of their body. In the future, technology like this could be used for continuous patient monitoring at home or at point-of-care settings.

The research, which was published in the journal ACS Nano, was led by Aydogan Ozcan, UCLA’s Chancellor’s Professor of Electrical Engineering and Bioengineering and associate director of the California NanoSystems Institute and Vasiliki Demas of Verily Life Sciences (formerly Google Life Sciences).

Fluorescent biomarkers are routinely used for cancer detection and drug delivery and release among other medical therapies. Recently, biocompatible fluorescent dyes have emerged, creating new opportunities for noninvasive sensing and measuring of biomarkers through the skin.

However, detecting artificially added fluorescent objects under the skin is challenging. Collagen, melanin and other biological structures emit natural light in a process called autofluorescence. Various methods have been tried to investigate this problem using different sensing systems. Most are quite expensive and difficult to make small and cost-effective enough to be used in a wearable imaging system.

To test the mobile microscope, researchers first designed a tissue phantom — an artificially created material that mimics human skin optical properties, such as autofluorescence, absorption and scattering. The target fluorescent dye solution was injected into a micro-well with a volume of about one-hundredth of a microliter, thinner than a human hair, and subsequently implanted into the tissue phantom half a millimeter to 2 millimeters from the surface — which would be deep enough to reach blood and other tissue fluids in practice.

To measure the fluorescent dye, the wearable microscope created by Ozcan and his team used a laser to hit the skin at an angle. The fluorescent image at the surface of the skin was captured via the wearable microscope. The image was then uploaded to a computer where it was processed using a custom-designed algorithm, digitally separating the target fluorescent signal from the autofluorescence of the skin, at a very sensitive parts-per-billion level of detection.

“We can place various tiny bio-sensors inside the skin next to each other, and through our imaging system, we can tell them apart,” Ozcan said. “We can monitor all these embedded sensors inside the skin in parallel, even understand potential misalignments of the wearable imager and correct it to continuously quantify a panel of biomarkers.”

This computational imaging framework might also be used in the future to continuously monitor various chronic diseases through the skin using an implantable or injectable fluorescent dye.

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

Quantitative Fluorescence Sensing Through Highly Autofluorescent, Scattering, and Absorbing Media Using Mobile Microscopy by Zoltán Göröcs, Yair Rivenson, Hatice Ceylan Koydemir, Derek Tseng, Tamara L. Troy, Vasiliki Demas, and Aydogan Ozcan. ACS Nano, 2016, 10 (9), pp 8989–8999 DOI: 10.1021/acsnano.6b05129 Publication Date (Web): September 13, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Space cloth (Zephlinear): a new technique for producing textiles

A lightweight zephlinear scarf with LEDs Courtesy: Nottingham Trent University

A lightweight zephlinear [space cloth]  scarf with LEDs Courtesy: Nottingham Trent University

What makes the scarf in the preceding image unusual is that the yarn hasn’t been knitted or woven. A Sept. 21, 2016 news item on phys.org describes the work,

Sonia Reynolds invented ‘space cloth’ – the first non-woven material made from yarn. It has a strong potential for use as a smart textile due to its unique structure with space to encase copper wiring, light emitting diodes (LEDs) and more.

Ms Reynolds brought the idea to Nottingham Trent University’s Advanced Textile Research Group and is now undertaking a PhD in the subject to further develop the fabric’s novel manufacturing process under the direction of Professor Tilak Dias and Dr Amanda Briggs-Goode, of the School of Art and Design.

Scientifically named Zephlinear, unlike traditional woven or knitted materials which are made by the interloping or interlacing of yarns, it is made by a newly established technique known as yarn surface entanglement.

A Sept. 21, 2016 Nottingham Trent University press release, which originated the news item, provides more information,

Ms Reynolds said: “This is a real breakthrough for the textiles industry. It’s the first non-woven material made from yarn and promises major benefits for the future of clothing, and more.

“Because of the material’s linear channels of yarn, it has great potential to be used as a smart textile. In particular, we believe it lends itself well to being embedded with microcapsules containing medication or scent, to either help deliver drugs to specific parts of the body or to create antibacterial and aromatic clothing.

“As the material is visually different, it has potential to be used for other applications as well, such as wall coverings, in addition to clothing.

“And because it’s much less labour intensive to make than knit or weave fabrics, it’s a more environmentally friendly material to produce as well.”

The name, Zephlinear, derives from the merger of two words, zephyr and linear. It was given the nickname ‘space cloth’ due to its appearance and its e-textile capabilities.

The material – which is patent pending – was recently presented at the Wearable Technology Show, USA, by Ms Reynolds.

Research shows that it is strongest and most efficient when created from natural yarns such as one hundred per cent wool, hair and wool/silk mixtures, though it can also be made from synthetic yarns.

Professor Dias, who leads the university’s Advanced Textiles Research Group, said: “Zephlinear is a remarkable development in an industry which is advancing at an incredible pace.

“We believe it has huge potential for textiles, and we have already found that it combines well with e-textile technologies such as heated textiles or textiles with embedded LEDs.

“As a fabric it is very lightweight and flexible, and it retracts back to its original shape well after it has been stretched.

“We’re very much looking forward to developing the material further and feel certain that it will help provide people with smarter and more environmentally friendly clothing in the future”.

Here’s an image of Sonia Reynolds with another Zephlinear scarf,

Sonia Reynolds with a zephlinear scarf Courtesy Nottingham Trent University

Sonia Reynolds with a zephlinear scarf Courtesy Nottingham Trent University

This is the first time I’ve heard of a ‘smart’ or ‘e’ textile that works better when a natural fiber is used.