Category Archives: clothing

3D printed clothing

A seamless garment or article of footwear would minimize skin irritation for those of us not able to afford custom couture and an April 19, 2016 news item on ScienceDaily offers hope in an announcement of efforts by a team of UK scientists to change the textile industry’s approach to garment and footwear construction,

Loughborough University has teamed up with global textile and garment manufacturer the Yeh Group, to embark on landmark work in 3D textile printing that could revolutionise how clothes and footwear are made.

Personalised 3D printed fashion — manufactured within 24 hours — is the end goal of a new project led by Loughborough University that’s set to change the way we shop for clothes.

An April 18, 2016 Loughborough University press release, which originated the news item, describes the project (Note: Links have been removed),

Dr Guy Bingham, Senior Lecturer in Product and Industrial Design, has teamed up with global textile and garment manufacturer the Yeh Group, to embark on landmark work in 3D textile printing that could revolutionise how clothes and footwear are made.

The 18-month project[1], known as 3D Fashion, will see Dr Bingham – a world leader in his field – produce 3D wearable, full size, Additive Manufacturing (AM) textile garments and footwear – with design input from a major fashion house.

Advancements in AM textiles have made it possible to produce 3D printed garments directly from raw material, such as polymer, in a single manufacturing operation. This technology not only has the potential to reduce waste, labour costs and CO2e, but can modernise clothing production by encouraging localised manufacturing and production.

Currently, garment manufacture generates 1.8 million tonnes of waste material – equivalent to 70kg or 100 pairs of jeans per UK household, with 6.3 billion m³ of water used in the process – equivalent to 200,000 litres per year per household or 1,000 filled bathtubs[2].

Dr Bingham said: “With 3D printing there is no limit to what you can build and it is this design freedom which makes the technology so exciting by bringing to life what was previously considered to be impossible.

“This landmark technology allows us as designers to innovate faster and create personalised, ready-to-wear fashion in a digital world with no geometrical constraints and almost zero waste material. We envisage that with further development of the technology, we could 3D print a garment within 24 hours.

David Yeh, Managing Director, Tong Siang (Yeh Group), said: “3D Fashion supports the Yeh Group vision of direct polymer to garment manufacture. The Yeh Group is always striving to cut out unnecessary waste and resource use, and support the industries goals of faster to market, creating a manufacturing technology that brands and retailers can install closer to their customers. This is all with no compromise to performance.”

Loughborough University has produced a video about this project,

You can find out more about the Yeh Group on their website or on their Facebook page. I believe the company is headquartered in Thailand but I can’t tell if Tong Siang (the Yeh Group? on LinkedIn) is the corporate parent, the subsidiary, or an alternate company name.

Embroidering electronics into clothing

Researchers at The Ohio State University are developing embroidered antennas and circuits with 0.1 mm precision—the perfect size to integrate electronic components such as sensors and computer memory devices into clothing. Photo by Jo McCulty, courtesy of The Ohio State University.

Researchers at The Ohio State University are developing embroidered antennas and circuits with 0.1 mm precision—the perfect size to integrate electronic components such as sensors and computer memory devices into clothing. Photo by Jo McCulty, courtesy of The Ohio State University.

An April 13, 2016 news item on Nanowerk describes an advance in the field of wearable electronics,

Researchers who are working to develop wearable electronics have reached a milestone: They are able to embroider circuits into fabric with 0.1 mm precision—the perfect size to integrate electronic components such as sensors and computer memory devices into clothing.

With this advance, the Ohio State University researchers have taken the next step toward the design of functional textiles—clothes that gather, store, or transmit digital information. With further development, the technology could lead to shirts that act as antennas for your smart phone or tablet, workout clothes that monitor your fitness level, sports equipment that monitors athletes’ performance, a bandage that tells your doctor how well the tissue beneath it is healing—or even a flexible fabric cap that senses activity in the brain.

That last item is one that John Volakis, director of the ElectroScience Laboratory at Ohio State, and research scientist Asimina Kiourti are investigating. The idea is to make brain implants, which are under development to treat conditions from epilepsy to addiction, more comfortable by eliminating the need for external wiring on the patient’s body.

An April 13, 2016 Ohio State University news release by Pam Frost Gorder, which originated the news item, expands on the theme (Note: Links have been removed),

“A revolution is happening in the textile industry,” said Volakis, who is also the Roy & Lois Chope Chair Professor of Electrical Engineering at Ohio State. “We believe that functional textiles are an enabling technology for communications and sensing—and one day even medical applications like imaging and health monitoring.”

Recently, he and Kiourti refined their patented fabrication method to create prototype wearables at a fraction of the cost and in half the time as they could only two years ago. With new patents pending, they published the new results in the journal IEEE Antennas and Wireless Propagation Letters.

In Volakis’ lab, the functional textiles, also called “e-textiles,” are created in part on a typical tabletop sewing machine—the kind that fabric artisans and hobbyists might have at home. Like other modern sewing machines, it embroiders thread into fabric automatically based on a pattern loaded via a computer file. The researchers substitute the thread with fine silver metal wires that, once embroidered, feel the same as traditional thread to the touch.

“We started with a technology that is very well known—machine embroidery—and we asked, how can we functionalize embroidered shapes? How do we make them transmit signals at useful frequencies, like for cell phones or health sensors?” Volakis said. “Now, for the first time, we’ve achieved the accuracy of printed metal circuit boards, so our new goal is to take advantage of the precision to incorporate receivers and other electronic components.”

The shape of the embroidery determines the frequency of operation of the antenna or circuit, explained Kiourti.

The shape of one broadband antenna, for instance, consists of more than half a dozen interlocking geometric shapes, each a little bigger than a fingernail, that form an intricate circle a few inches across. Each piece of the circle transmits energy at a different frequency, so that they cover a broad spectrum of energies when working together—hence the “broadband” capability of the antenna for cell phone and internet access.

“Shape determines function,” she said. “And you never really know what shape you will need from one application to the next. So we wanted to have a technology that could embroider any shape for any application.”

The researchers’ initial goal, Kiourti added, was just to increase the precision of the embroidery as much as possible, which necessitated working with fine silver wire. But that created a problem, in that fine wires couldn’t provide as much surface conductivity as thick wires. So they had to find a way to work the fine thread into embroidery densities and shapes that would boost the surface conductivity and, thus, the antenna/sensor performance.

Previously, the researchers had used silver-coated polymer thread with a 0.5-mm diameter, each thread made up of 600 even finer filaments twisted together. The new threads have a 0.1-mm diameter, made with only seven filaments. Each filament is copper at the center, enameled with pure silver.

They purchase the wire by the spool at a cost of 3 cents per foot; Kiourti estimated that embroidering a single broadband antenna like the one mentioned above consumes about 10 feet of thread, for a material cost of around 30 cents per antenna. That’s 24 times less expensive than when Volakis and Kiourti created similar antennas in 2014.

In part, the cost savings comes from using less thread per embroidery. The researchers previously had to stack the thicker thread in two layers, one on top of the other, to make the antenna carry a strong enough electrical signal. But by refining the technique that she and Volakis developed, Kiourti was able to create the new, high-precision antennas in only one embroidered layer of the finer thread. So now the process takes half the time: only about 15 minutes for the broadband antenna mentioned above.

She’s also incorporated some techniques common to microelectronics manufacturing to add parts to embroidered antennas and circuits.

One prototype antenna looks like a spiral and can be embroidered into clothing to improve cell phone signal reception. Another prototype, a stretchable antenna with an integrated RFID (radio-frequency identification) chip embedded in rubber, takes the applications for the technology beyond clothing. (The latter object was part of a study done for a tire manufacturer.)

Yet another circuit resembles the Ohio State Block “O” logo, with non-conductive scarlet and gray thread embroidered among the silver wires “to demonstrate that e-textiles can be both decorative and functional,” Kiourti said.

They may be decorative, but the embroidered antennas and circuits actually work. Tests showed that an embroidered spiral antenna measuring approximately six inches across transmitted signals at frequencies of 1 to 5 GHz with near-perfect efficiency. The performance suggests that the spiral would be well-suited to broadband internet and cellular communication.

In other words, the shirt on your back could help boost the reception of the smart phone or tablet that you’re holding – or send signals to your devices with health or athletic performance data.

The work fits well with Ohio State’s role as a founding partner of the Advanced Functional Fabrics of America Institute, a national manufacturing resource center for industry and government. The new institute, which joins some 50 universities and industrial partners, was announced earlier this month by U.S. Secretary of Defense Ashton Carter.

Syscom Advanced Materials in Columbus provided the threads used in Volakis and Kiourti’s initial work. The finer threads used in this study were purchased from Swiss manufacturer Elektrisola. The research is funded by the National Science Foundation, and Ohio State will license the technology for further development.

Until then, Volakis is making out a shopping list for the next phase of the project.

“We want a bigger sewing machine,” he said.

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

Fabrication of Textile Antennas and Circuits With 0.1 mm Precision by A. Kiourti, C. Lee, and J. L. Volakis.  IEEE Antennas and Wireless Propagation Letters (Volume:15 ) Page(s): 151 – 153 ISSN : 1536-1225 INSPEC Accession Number: 15785288 DOI: 10.1109/LAWP.2015.2435257 Date of Publication: 20 May 2015 Issue Date: 2016

This paper is behind a paywall.

Clothes washers and dryers begone! Nano-enhanced textiles can self-clean

It will be a while yet even it this technique proves to be viable commercially, still, the possibilities tantalize: self-cleaning textiles. A March 22, 2016 news item on ScienceDaily announced research in Australia that may, one day, change your life,

A spot of sunshine is all it could take to get your washing done, thanks to pioneering nano research into self-cleaning textiles.

Researchers at RMIT University in Melbourne, Australia, have developed a cheap and efficient new way to grow special nanostructures — which can degrade organic matter when exposed to light — directly onto textiles.

The work paves the way towards nano-enhanced textiles that can spontaneously clean themselves of stains and grime simply by being put under a light bulb or worn out in the sun.

A March 22, 2016 RMIT media release (also on EurekAlert), which originated the news item, expands on the theme,

Dr Rajesh Ramanathan said the process developed by the team had a variety of applications for catalysis-based industries such as agrochemicals, pharmaceuticals and natural products, and could be easily scaled up to industrial levels.

“The advantage of textiles is they already have a 3D structure so they are great at absorbing light, which in turn speeds up the process of degrading organic matter,” he said.

“There’s more work to do to before we can start throwing out our washing machines, but this advance lays a strong foundation for the future development of fully self-cleaning textiles.”

The researchers from the Ian Potter NanoBioSensing Facility and NanoBiotechnology Research Lab at RMIT worked with copper and silver-based nanostructures, which are known for their ability to absorb visible light.

When the nanostructures are exposed to light, they receive an energy boost that creates “hot electrons”. These “hot electrons” release a burst of energy [emphasis mine] that enables the nanostructures to degrade organic matter.

The challenge for researchers has been to bring the concept out of the lab by working out how to build these nanostructures on an industrial scale and permanently attach them to textiles.

The RMIT team’s novel approach was to grow the nanostructures directly onto the textiles by dipping them into a few solutions, resulting in the development of stable nanostructures within 30 minutes.

When exposed to light, it took less than six minutes for some of the nano-enhanced textiles to spontaneously clean themselves.

“Our next step will be to test our nano-enhanced textiles with organic compounds that could be more relevant to consumers, to see how quickly they can handle common stains like tomato sauce or wine,” Ramanathan said.

I wonder if these “hot electrons” mean that when they release “a burst of energy” your clothing will heat up when exposed to light? This image supplied by the researchers does not help to answer the question but it is intriguing,

Caption: Close-up of the nanostructures grown on cotton textiles by RMIT University researchers. Image magnified 150,000 times. Credit: RMIT University

Caption: Close-up of the nanostructures grown on cotton textiles by RMIT University researchers. Image magnified 150,000 times. Credit: RMIT University

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

Robust Nanostructured Silver and Copper Fabrics with Localized Surface Plasmon Resonance Property for Effective Visible Light Induced Reductive Catalysis by Samuel R. Anderson, Mahsa Mohammadtaheri, Dipesh Kumar, Anthony P. O’Mullane, Matthew R. Field, Rajesh Ramanathan, and Vipul Bansal. Advanced Materials Interfaces DOI: 10.1002/admi.201500632 Article first published online: 7 JAN 2016

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

This paper is behind a paywall.

A wearable, stretchable body sensor based on chewing gum and carbon nanotubes

Any work which features a scientist chewing gum preparatory to using it for research purposes should be widely disseminated. In all the talk about science and equipment, it’s easy to forget that scientists are capable of great ingenuity with simple, every day materials. Also, the researchers are Canadian and based at the University of Manitoba. From a Dec. 2, 2015 American Chemical Society (ACS) news release (also on EurekAlert),

Body sensors, which were once restricted to doctors’ offices, have come a long way. They now allow any wearer to easily track heart rate, steps and sleep cycles around the clock. Soon, they could become even more versatile — with the help of chewing gum. Scientists report in the journal ACS Applied Materials & Interfaces a unique sensing device made of gum and carbon nanotubes that can move with your most bendable parts and track your breathing.

Most conventional sensors today are very sensitive and detect the slightest movement, but many are made out of metal. That means when they’re twisted or pulled too much, they stop working. But for sensors to monitor the full range of a body’s bending and stretching, they need a lot more give. To meet that need, some researchers have tried developing sensors using stretchy plastics and silicones. But what they gained in flexibility, they lost in sensitivity. Malcolm Xing and colleagues found a better solution right under their noses — and in their mouths.

To make their supple sensor, a team member chewed a typical piece of gum for 30 minutes, washed it with ethanol and let it sit overnight. The researchers then added a solution of carbon nanotubes, the sensing material. Simple pulling and folding coaxed the tubes to align properly. Human finger-bending and head-turning tests showed the material could keep working with high sensitivity even when strained 530 percent. The sensor also could detect humidity changes, a feature that could be used to track breathing, which releases water vapor with every exhale.

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

Gum Sensor: A Stretchable, Wearable, and Foldable Sensor Based on Carbon Nanotube/Chewing Gum Membrane by Mohammad Ali Darabi, Ali Khosrozadeh, Quan Wang, and Malcolm Xing. ACS Appl. Mater. Interfaces, 2015, 7 (47), pp 26195–26205 DOI: 10.1021/acsami.5b08276 Publication Date (Web): November 2, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

This video lets you see the gum/CNT material at work,

Enjoy!

Shape memory in a supercapacitor fibre for ‘smart’ textiles (wearable tech: 1 of 3)

Wearable technology seems to be quite trendy for a grouping not usually seen: consumers, fashion designers, medical personnel, manufacturers, and scientists.

The first in this informal series concerns a fibre with memory shape. From a Nov. 19, 2015 news item on Nanowerk (Note: A link has been removed),

Wearing your mobile phone display on your jacket sleeve or an EKG probe in your sports kit are not off in some distant imagined future. Wearable “electronic textiles” are on the way. In the journal Angewandte Chemie (“A Shape-Memory Supercapacitor Fiber”), Chinese researchers have now introduced a new type of fiber-shaped supercapacitor for energy-storage textiles. Thanks to their shape memory, these textiles could potentially adapt to different body types: shapes formed by stretching and bending remain “frozen”, but can be returned to their original form or reshaped as desired.

A Nov. 19, 2015 Wiley Publishers press release, which originated the news item, provides context and detail about the work,

Any electronic components designed to be integrated into textiles must be stretchable and bendable. This is also true of the supercapacitors that are frequently used for data preservation in static storage systems (SRAM). SRAM is a type of storage that holds a small amount of data that is rapidly retrievable. It is often used for caches in processors or local storage on chips in devices whose data must be stored for long periods without a constant power supply. Some time ago, a team headed by Huisheng Peng at Fudan University developed stretchable, pliable fiber-shaped supercapacitors for integration into electronic textiles. Peng and his co-workers have now made further progress: supercapacitor fibers with shape memory.

Any electronic components designed to be integrated into textiles must be stretchable and bendable. This is also true of the supercapacitors that are frequently used for data preservation in static storage systems (SRAM). SRAM is a type of storage that holds a small amount of data that is rapidly retrievable. It is often used for caches in processors or local storage on chips in devices whose data must be stored for long periods without a constant power supply.
Some time ago, a team headed by Huisheng Peng at Fudan University developed stretchable, pliable fiber-shaped supercapacitors for integration into electronic textiles. Peng and his co-workers have now made further progress: supercapacitor fibers with shape memory.

The fibers are made using a core of polyurethane fiber with shape memory. This fiber is wrapped with a thin layer of parallel carbon nanotubes like a sheet of paper. This is followed by a coating of electrolyte gel, a second sheet of carbon nanotubes, and a final layer of electrolyte gel. The two layers of carbon nanotubes act as electrodes for the supercapacitor. Above a certain temperature, the fibers produced in this process can be bent as desired and stretched to twice their original length. The new shape can be “frozen” by cooling. Reheating allows the fibers to return to their original shape and size, after which they can be reshaped again. The electrochemical performance is fully maintained through all shape changes.

Weaving the fibers into tissues results in “smart” textiles that could be tailored to fit the bodies of different people. This could be used to make precisely fitted but reusable electronic monitoring systems for patients in hospitals, for example. The perfect fit should render them both more comfortable and more reliable.

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

A Shape-Memory Supercapacitor Fiber by Jue Deng, Ye Zhang, Yang Zhao, Peining Chen, Dr. Xunliang Cheng, & Prof. Dr. Huisheng Peng. Angewandte Chemie International Edition  DOI: 10.1002/anie.201508293  First published: 3 November 2015

This paper is behind a paywall.

Clothing which turns you into a billboard

This work from a Belgian-Dutch initiative has the potential to turn us into billboards. From a Sept. 2, 2015 news item on Nanowerk,

Researchers from Holst Centre (set up by TNO and imec), imec and CMST, imec’s associated lab at Ghent University [Belgium], have demonstrated the world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles. This paves the way to wearable displays in clothing providing users with feedback.

Here’s what it looks like,

A Sept. 2, 2015 Holst Centre press release, which originated the news item, provides more details,

“Wearable devices allow people to monitor their fitness and health so they can live full and active lives for longer. But to maximize the benefits wearables can offer, they need to be able to provide feedback on what users are doing as well as measuring it. By combining imec’s patented stretch technology with our expertise in active-matrix backplanes and integrating electronics into fabrics, we’ve taken a giant step towards that possibility,” says Edsger Smits, Senior research scientist at Holst Centre.

The conformable display is very thin and mechanically stretchable. A fine-grain version of the proven meander interconnect technology was developed by the CMST lab at Ghent University and Holst Centre to link standard (rigid) LEDs into a flexible and stretchable display. The LED displays are fabricated on a polyimide substrate and encapsulated in rubber, allowing the displays to be laminated in to textiles that can be washed. Importantly, the technology uses fabrication steps that are known to the manufacturing industry, enabling rapid industrialization.

Following an initial demonstration at the Society for Information Display’s Display Week in San Jose, USA earlier this year, Holst Centre has presented the next generation of the display at the International Meeting on Information Display (IMID) in Daegu, Korea, 18-21 August 2015. Smaller LEDs are now mounted on an amorphous indium-gallium-zinc oxide (a-IGZO) TFT backplane that employs a two-transistor and one capacitor (2T-1C) pixel engine to drive the LEDs. These second-generation displays offer higher pitch and increased, average brightness. The presentation will feature a 32×32 pixel demonstrator with a resolution of 13 pixels per inch (ppi) and average brightness above 200 candelas per square meter (cd/m2). Work is ongoing to further industrialize this technology.

There are some references for the work offered at the end of the press release but I believe they are citing their conference presentations,

9.4: Stretchable 45 × 80 RGB LED Display Using Meander Wiring Technology, Ohmae et al. SID 2015, June 2015

1.2: Rollable, Foldable and Stretchable Displays, Gelinck et al. IMID, Aug. 2015.

13.4 A conformable Active Matrix LED Display, Tripathi et al. IMID, Aug. 2015

For anyone interested in imec formerly the Interuniversity Microelectronics Centre, there’s this Wikipedia entry, and in TNO (Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek in Dutch), there’s this Wikipedia entry.

Slaughterhouse yarn (scientists looking for business investment)

Not everyone is going to feel comfortable with the idea of using gelatine to create fibres for yarn. Nonetheless, here’s a July 29, 2015 ETH Zurich (Swiss Federal Institute of Technology in Zurich, [Eidgenössische Technische Hochschule Zürich]) press release (also on EurekAlert) describes the research (a plea for business investment follows),

Some 70 million tonnes of fibres are traded worldwide every year. Man-made fibres manufactured from products of petroleum or natural gas account for almost two-thirds of this total. The most commonly used natural fibres are wool and cotton, but they have lost ground against synthetic fibres.

Despite their environmental friendliness, fibres made of biopolymers from plant or animal origin remain very much a niche product. At the end of the 19th century, there were already attempts to refine proteins into textiles. For example, a patent for textiles made of gelatine was filed in 1894. After the Second World War, however, the emerging synthetic fibres drove biological protein fibres swiftly and thoroughly from the market.

Over the past few years, there has been increased demand for natural fibres produced from renewable resources using environmentally friendly methods. Wool fibre in particular has experienced a renaissance in performance sportswear made of merino wool. And a few years ago, a young entrepreneur in Germany started making high-quality textiles from the milk protein casein.

New use for waste product

Now Philipp Stössel, a 28-year-old PhD student in Professor Wendelin Stark’s Functional Materials Laboratory (FML), is presenting a new method for obtaining high-quality fibres from gelatine. The method was developed in cooperation with the Advanced Fibers Laboratory at Empa St. Gallen. Stössel was able to spin the fibres into a yarn from which textiles can be manufactured.

Gelatine consists chiefly of collagen, a main component of skin, bone and tendons. Large quantities of collagen are found in slaughterhouse waste and can be easily made into gelatine. For these reasons, Stark and Stössel decided to use this biomaterial for their experiments.

Coincidence helps provide a solution

In his experiments, Stössel noticed that when he added an organic solvent (isopropyl) to a heated, aqueous gelatine solution, the protein precipitated at the bottom of the vessel. He removed the formless mass using a pipette and was able to effortlessly press an elastic, endless thread from it. This was the starting point for his unusual research work.

As part of his dissertation, Stössel developed and refined the method, which he has just recently presented in an article for the journal Biomacromolecules.

The refined method replaces the pipette with several syringe drivers in a parallel arrangement. Using an even application of pressure, the syringes push out fine endless filaments, which are guided over two Teflon-coated rolls. The rolls are kept constantly moist in an ethanol bath; this prevents the filaments from sticking together and allows them to harden quickly before they are rolled onto a conveyor belt. Using the spinning machine he developed, Stössel was able to produce 200 metres of filaments a minute. He then twisted around 1,000 individual filaments into a yarn with a hand spindle and had a glove knitted from the yarn as a showpiece.

Attractive luster

Extremely fine, the individual fibres have a diameter of only 25 micrometres, roughly half the thickness of a human hair. With his first laboratory spinning machines, the fibre thickness was 100 micrometres, Stössel recalls. That was too thick for yarn production.

Whereas natural wool fibres have tiny scales, the surface of the gelatine fibres is smooth. “As a result, they have an attractive luster,” Stössel says. Moreover, the interior of the fibres is filled with cavities, as shown by the researchers’ electron microscope images. This might also be the reason for the gelatine yarn’s good insulation, which Stössel was able to measure in comparison with a glove made of merino wool.

Water-resistant fibres

Gelatine’s major drawback is that it its water-solubility. Stössel had to greatly improve the water resistance of the gelatine yarn through various chemical processing stages. First he treated the glove with an epoxy in order to bond the gelatine components more firmly together. Next, he treated the material with formaldehyde so that it would harden better. Finally, he impregnated the yarn with lanolin, a natural wool grease, to make it supple.

As he completes his dissertation over the coming months, Stössel will research how to make the gelatine fibres even more water-resistant. Sheep’s wool is still superior to the gelatine yarn in this respect. However, Stössel is convinced that he is very close to his ultimate goal: making a biopolymer fibre from a waste product.

It’s been a few months since I’ve seen one of these pleas for commercial interest/partnership (from the press release),

Three years ago, the researchers applied for a patent on their invention. Stössel explains that they have reached the point where their capacity in the laboratory is at its limit, but commercial production will only be possible if they can find partners and funding.

Here’s a link to and a citation for the researchers’ latest published paper (there are also two previous paper listed in the press release),

Porous, Water-Resistant Multifilament Yarn Spun from Gelatin by Philipp R. Stoessel, Urs Krebs, Rudolf Hufenus, Marcel Halbeisen, Martin Zeltner, Robert N. Grass, and Wendelin J. Stark. Biomacromolecules, 2015, 16 (7), pp 1997–2005 DOI: 10.1021/acs.biomac.5b00424 Publication Date (Web): June 2, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

Hong Kong, MosquitNo, and Dengue fever

The most substantive piece I’ve written on dengue fever and a nanotechnology-enabled approach to the problem was a 2013 post explaining why the fever is of such concern, which also included information about a proposed therapeutic intervention by Nanoviricides. From the July 2, 2013 posting, here’s more about the magnitude of the problem,

… the WHO (World Health Organization) fact sheet no. 117,

The incidence of dengue has grown dramatically around the world in recent decades. Over 2.5 billion people – over 40% of the world’s population – are now at risk from dengue. WHO currently estimates there may be 50–100 million dengue infections worldwide every year.

Before 1970, only nine countries had experienced severe dengue epidemics. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. The American, South-east Asia and the Western Pacific regions are the most seriously affected.

Cases across the Americas, South-east Asia and Western Pacific have exceeded 1.2 million cases in 2008 and over 2.3 million in 2010 (based on official data submitted by Member States). Recently the number of reported cases has continued to increase. In 2010, 1.6 million cases of dengue were reported in the Americas alone, of which 49 000 cases were severe dengue.

Not only is the number of cases increasing as the disease spreads to new areas, but explosive outbreaks are occurring. The threat of a possible outbreak of dengue fever now exists in Europe and local transmission of dengue was reported for the first time in France and Croatia in 2010 and imported cases were detected in three other European countries. A recent (2012) outbreak of dengue on Madeira islands of Portugal has resulted in over 1800 cases and imported cases were detected in five other countries in Europe apart from mainland Portugal.

An estimated 500 000 people with severe dengue require hospitalization each year, a large proportion of whom are children. About 2.5% of those affected die.

Fast forwarding to 2015, this latest information about dengue fever features a preventative approach being taken in Hong Kong according to a July 5, 2015 article by Timmy Sung  for the South China Morning Post,

Dutch insect repellent innovator Mosquitno targets Hong Kong as dengue fever cases rise

A Dutch company says it has invented an insect repellent using nanotechnology which can keep clothes and homes mosquito-free for up to three months.

Mosquitno has been invited by a government body to begin trading in Hong Kong as the number of cases reported in the city of the deadly mosquito-borne dengue fever rises.

The new repellent does not include the active ingredient used in many insect repellents, DEET, which has question marks surrounding its safety.

Figures from the Department of Health show the number of dengue fever cases reported rose 8 per cent last year, to 112. There were 34 cases in the first five months of this year, 36 per cent more than in the same period last year. Mosquitoes are most active in the summer months.

MosquitNo does use an ingredient, IR3535, which has caused concern (from Sung’s article),

The Consumer Council has previously warned that IR3535-based mosquito repellents can break down plastic materials and certain synthetic fibres, but Wijnen [Erwin Wijnen, director of the {Mosqutino’s} brand development and global travel retailing] said the ingredient combined with nanotechnology is safe and there was no possibility it would damage clothes.

I was not able to find out more about the company’s nanotechnology solution as applied to MosquitNo,

The NANO Series is a revolutionary, innovative technology designed by scientists especially for MosquitNo. This line utilizes this-breaking insect repellent technology in various products including wipes, textile spray, fabric softener and bracelets. This technology and our trendy applications are truly industry-changing and MosquitNo is at the leading edge!

The active component in all our awesome products within this range is IR3535.

That’s it for technical detail. At least, for now.

Not origami but kirigami-inspired foldable batteries

Origami is not noted for its stretchy qualities, a shortcoming according to a June 16, 2015 news item on Azonano,

Origami, the centuries-old Japanese paper-folding art, has inspired recent designs for flexible energy-storage technology. But energy-storage device architecture based on origami patterns has so far been able to yield batteries that can change only from simple folded to unfolded positions. They can flex, but not actually stretch.

Now an Arizona State University [ASU] research team has overcome the limitation by using a variation of origami, called kirigami, as a design template for batteries that can be stretched to more than 150 percent of their original size and still maintain full functionality.

A June 15, 2015 ASU news release, which originated the news item, provides a few more details about the kirigami-influenced batteries (Note: A link has been removed),

A paper published on June 11 [2015] in the research journal Scientific Reports describes how the team developed kirigami-based lithium-ion batteries using a combination of folds and cuts to create patterns that enable a significant increase in stretchability.

The kirigami-based prototype battery was sewn into an elastic wristband that was attached to a smart watch. The battery fully powered the watch and its functions – including playing video – as the band was being stretched.

“This type of battery could potentially be used to replace the bulky and rigid batteries that are limiting the development of compact wearable electronic devices,” Jiang said.

Such stretchable batteries could even be integrated into fabrics – including those used for clothing, he said.

The researchers have provided a video demonstrating the kirigami-inspired battery in action,

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

Kirigami-based stretchable lithium-ion batteries by Zeming Song, Xu Wang, Cheng Lv, Yonghao An, Mengbing Liang, Teng Ma, David He, Ying-Jie Zheng, Shi-Qing Huang, Hongyu Yu & Hanqing Jiang. Scientific Reports 5, Article number: 10988 doi:10.1038/srep10988 Published 11 June 2015

This is an open access paper.

According to the ASU news release, the team published a previous paper on origami-inspired batteries and some of the problems associated with them (Note: Links have been removed),

An earlier paper in the research journal Nature Communications by Jiang and some of his research team members and other colleagues provides an in-depth look at progress and obstacles in the development of origami-based lithium-ion batteries.

The paper explains technical challenges in flexible-battery development that Jiang says his team’s kirigami-based devices are helping to solve.

Read more about the team’s recent progress and the potential applications of stretchable batteries in Popular Mechanics, the Christian Science Monitor, Yahoo News and the Daily Mail.

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

Origami lithium-ion batteries by Zeming Song, Teng Ma,    Rui Tang, Qian Cheng, Xu Wang, Deepakshyam Krishnaraju, Rahul Panat, Candace K. Chan, Hongyu Yu, & Hanqing Jiang. Nature Communications 5, Article number: 3140 doi:10.1038/ncomms4140 Published 28 January 2014

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

On a related note, Dexter Johnson has written up Binghamton University research into paper-based origami batteries powered by the respiration of bacteria in a June 16, 2015 posting on his Nanoclast blog.

ATTACH for smart clothes and personalized heating and cooling

If this research into clothing that can heat or warm you as needed sounds familiar, it is. A team out of Stanford University (US) reported on research they conducted (pun noted) using special cloth coated with metallic nanowires to achieve personalized heating and cooling (my Jan. 9, 2015 post).

Now there is a second US team, also based in southern California, working on personalized heating and cooling. Researchers at the University of California at San Diego (UCSD) have received a $2.6M grant to pursue this goal, from a June 1, 2015 news item on Nanowerk,

Imagine a fabric that will keep your body at a comfortable temperature—regardless of how hot or cold it actually is. That’s the goal of an engineering project at the University of California, San Diego, funded with a $2.6M grant from the U.S. Department of Energy’s Advanced Research Projects Agency – Energy (ARPA-E). Wearing this smart fabric could potentially reduce heating and air conditioning bills for buildings and homes.

The project, named ATTACH (Adaptive Textiles Technology with Active Cooling and Heating), is led by Joseph Wang, distinguished professor of nanoengineering at UC San Diego.

By regulating the temperature around an individual person, rather than a large room, the smart fabric could potentially cut the energy use of buildings and homes by at least 15 percent, Wang noted.

“In cases where there are only one or two people in a large room, it’s not cost-effective to heat or cool the entire room,” said Wang. “If you can do it locally, like you can in a car by heating just the car seat instead of the entire car, then you can save a lot of energy.”

A June 1, 2015 UCSD news release (also on EurekAlert), which originated the news item, describes the team’s hopes and dreams for the technology and provides some biographical information (Note: Some links have been removed),

The smart fabric will be designed to regulate the temperature of the wearer’s skin–keeping it at 93° F–by adapting to temperature changes in the room. When the room gets cooler, the fabric will become thicker. When the room gets hotter, the fabric will become thinner. To accomplish this feat, the researchers will insert polymers that expand in the cold and shrink in the heat inside the smart fabric.

“Regardless if the surrounding temperature increases or decreases, the user will still feel the same without having to adjust the thermostat,” said Wang.

“93° F is the average comfortable skin temperature for most people,” added Renkun Chen, assistant professor of mechanical and aerospace engineering at UC San Diego, and one of the collaborators on this project.

Chen’s contribution to ATTACH is to develop supplemental heating and cooling devices, called thermoelectrics, that are printable and will be incorporated into specific spots of the smart fabric. The thermoelectrics will regulate the temperature on “hot spots”–such as areas on the back and underneath the feet–that tend to get hotter than other parts of the body when a person is active.

“This is like a personalized air-conditioner and heater,” said Chen.

Saving energy

“With the smart fabric, you won’t need to heat the room as much in the winter, and you won’t need to cool the room down as much in the summer. That means less energy is consumed. Plus, you will still feel comfortable within a wider temperature range,” said Chen.

The researchers are also designing the smart fabric to power itself. The fabric will include rechargeable batteries, which will power the thermoelectrics, as well as biofuel cells that can harvest electrical power from human sweat. Plus, all of these parts–batteries, thermoelectrics and biofuel cells–will be printed using the technology developed in Wang’s lab to make printable wearable devices. These parts will also be thin, stretchable and flexible to ensure that the smart fabric is not bulky or heavy.

“We are aiming to make the smart clothing look and feel as much like the clothes that people regularly wear. It will be washable, stretchable, bendable and lightweight. We also hope to make it look attractive and fashionable to wear,” said Wang.

In terms of price, the team has not yet concluded how much the smart clothing will cost. This will depend on the scale of production, but the printing technology in Wang’s lab will offer a low-cost method to produce the parts. Keeping the costs down is a major goal, the researchers said.

The research team

Professor Joseph Wang, Department of NanoEngineering

Wang, the lead principal investigator of ATTACH, has pioneered the development of wearable printable devices, such as electrochemical sensors and temporary tattoo-based biofuel cells. He is the chair of the nanoengineering department and the director for the Center for Wearable Sensors at UC San Diego. His extensive expertise in printable, stretchable and wearable devices will be used here to make the proposed flexible biofuel cells, batteries and thermoelectrics.

Assistant Professor Renkun Chen, Department of Mechanical and Aerospace Engineering

Chen specializes in heat transfer and thermoelectrics. His research group works on physics, materials and devices related to thermal energy transport, conversion and management. His specialty in these areas will be used to develop the thermal models and the thermoelectric devices.

Associate Professor Shirley Meng, Department of NanoEngineering

Meng’s research focuses on energy storage and conversion, particularly on battery cell design and testing. At UC San Diego, she established the Laboratory for Energy Storage and Conversion and is the inaugural director for the Sustainable Power and Energy Center. Meng will develop the rechargeable batteries and will work on power integration throughout the smart fabric system.

Professor Sungho Jin, Department of Mechanical and Aerospace Engineering

Jin specializes in functional materials for applications in nanotechnology, magnetism, energy and biomedicine. He will design the self-responsive polymers that change in thickness based on changes in the surrounding temperature.

Dr. Joshua Windmiller, CEO of Electrozyme LLC

Windmiller, former Ph.D. student and postdoc in Wang’s nanoengineering lab, is an expert in printed biosensors, bioelectronics and biofuel cells. He co-founded Electrozyme LLC, a startup devoted to the development of novel biosensors for application in the personal wellness and healthcare domains. Electrozyme will serve as the industrial partner for ATTACH and will lead the efforts to test the smart fabric prototype and bring the technology into the market.

You can find out more about Electrozyme here.