Posts belonging to Category clothes



Paper Supercapacitor

By coating ordinary paper with layers of gold nanoparticles and other materials, researchers have fabricated flexible paper supercapacitors that exhibit the best performance of any textile-type supercapacitor to date. In particular, the paper supercapacitors address one of the biggest challenges in this area, which is to achieve a high energy density in addition to an already high power density, since both properties are essential for realizing high-performance energy-storage devices. In the future, flexible paper supercapacitors could be used in wearable electronics for biomedical, consumer, and military applications. The researchers, led by Seung Woo Lee at the Georgia Institute of Technology and Jinhan Cho at Korea University, have published a paper on the flexible paper supercapacitor electrodes in a recent issue of Nature Communications. As energy-storage devices, supercapacitors have several advantages over batteries, such as a higher power density, rapid charge/discharge rate, and longer lifetime, yet they lag behind batteries in energy density (the amount of energy that can be stored in a given amount of space). Although several methods have been attempted to improve the energy density of paper supercapacitors by coating them with various conductive materials, often these methods have the drawback of reducing the power density.

The paper electrodes based on layer-by-layer-assembled metal nanoparticles exhibit metal-like electric conductivity, paper-like mechanical properties, and a large surface area without any thermal treatment and/or mechanical pressing,” explains coauthor Yongmin Ko at Korea University. “The periodic insertion of metal nanoparticles within high-energy nanoparticle-based paper electrodes could resolve the critical tradeoff in which an increase in the loading amount of materials to enhance the energy density of supercapacitors decreases the power density.”
Tests  showed that the flexible paper supercapacitors had a maximum capacitance that is higher than any previously reported textile-based supercapacitor. In addition, the new devices exhibits an excellent capacity retention, demonstrated by a 90% capacity retention after 5,000 bending cycles.

Source: http://me.gatech.edu/

Nano-based Yarns Generate Electricity

An international research team led by scientists at The University of Texas at Dallas and Hanyang University in South Korea has developed high-tech yarns that generate electricity when they are stretched or twisted.

In a study published in the journal Science, researchers describe “twistronyarns and their possible applications, such as harvesting energy from the motion of ocean waves or from temperature fluctuations. When sewn into a shirt, these yarns served as a self-powered breathing monitor.

The easiest way to think of twistron harvesters is, you have a piece of yarn, you stretch it, and out comes electricity,” said Dr. Carter Haines BS’11, PhD’15, associate research professor in the Alan G. MacDiarmid NanoTech Institute at UT Dallas and co-lead author of the article. The article also includes researchers from South Korea, Virginia Tech, Wright-Patterson Air Force Base and China.

Coiled carbon nanotube yarns, created at The University of Texas at Dallas and imaged here with a scanning electron microscope, generate electrical energy when stretched or twisted.
The yarns are constructed from carbon nanotubes, which are hollow cylinders of carbon 10,000 times smaller in diameter than a human hair. The researchers first twist-spun the nanotubes into high-strength, lightweight yarns. To make the yarns highly elastic, they introduced so much twist that the yarns coiled like an over-twisted rubber band.

In order to generate electricity, the yarns must be either submerged in or coated with an ionically conducting material, or electrolyte, which can be as simple as a mixture of ordinary table salt and water.

Fundamentally, these yarns are supercapacitors,” said Dr. Na Li, a research scientist at the NanoTech Institute and co-lead author of the study. “In a normal capacitor, you use energy — like from a battery — to add charges to the capacitor. But in our case, when you insert the carbon nanotube yarn into an electrolyte bath, the yarns are charged by the electrolyte itself. No external battery, or voltage, is needed.

When a harvester yarn is twisted or stretched, the volume of the carbon nanotube yarn decreases, bringing the electric charges on the yarn closer together and increasing their energy, Haines said. This increases the voltage associated with the charge stored in the yarn, enabling the harvesting of electricity.

Source: http://www.utdallas.edu/

How To Keep Warm In Extreme Cold Weather

Some of the winter weather gear worn by the US Army was designed 30 years ago. It’s heavy and can cause overheating during exertion, while also not doing a very good job of keeping the extremities from going numb.

 

That’s problematic if soldiers have to operate weapons as soon as they land,” said Paola D’Angelo, a research bioengineer at the US Army’s Natick Soldier Research, Development and Engineering Center in Massachusetts. “So we want to pursue this fundamental research to see if we can modify hand wear for that extreme cold weather.”

Scientists are developing smart fabrics that heat up when powered and can capture sweat. The work, which was presented at the 254th National Meeting and Exposition of the American Chemical Society, is based on research from Stanford University in California. A team embedded a network of very fine silver nanowires in cotton, and was able to heat the fabric by applying power to the wires. D’Angelo and her colleagues are working to extend the approach to other fabrics more suitable for military uniforms, including polyester and a cotton/nylon blend. By applying three volts – the output of a typical watch battery – to a one-inch square of fabric, they were able to raise its temperature by almost 40 degrees C. The researchers are also incorporating a layer of hydrogel particles made of polyethylene glycol that will absorb sweat and stop the other layers of the fabric from getting wet.

Once we have optimised the coating, we can start looking at scaling up,” said D’Angelo. The fabric has been tested with up to three washes and still works the same as unwashed fabric for most of the textiles being tested.

Source: http://www.imeche.org/

Move And Produce Electricity To Power Your Phone

Imagine slipping into a jacket, shirt or skirt that powers your cell phone, fitness tracker and other personal electronic devices as you walk, wave and even when you are sitting down. A new, ultrathin energy harvesting system developed at Vanderbilt University’s Nanomaterials and Energy Devices Laboratory has the potential to do just that. Based on battery technology and made from layers of black phosphorus that are only a few atoms thick, the new device generates small amounts of electricity when it is bent or pressed even at the extremely low frequencies characteristic of human motion.

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In the future, I expect that we will all become charging depots for our personal devices by pulling energy directly from our motions and the environment,” said Assistant Professor of Mechanical Engineering Cary Pint, who directed the research.
This is timely and exciting research given the growth of wearable devices such as exoskeletons and smart clothing, which could potentially benefit from Dr. Pint’s advances in materials and energy harvesting,” observed Karl Zelik, assistant professor of mechanical and biomedical engineering at Vanderbilt, an expert on the biomechanics of locomotion who did not participate in the device’s development.

Doctoral students Nitin Muralidharan and Mengya Lic o-led the effort to make and test the devices. When you look at Usain Bolt, you see the fastest man on Earth. When I look at him, I see a machine working at 5 Hertz, said Muralidharan.

The new energy harvesting system is described in a paper titled “Ultralow Frequency Electrochemical Mechanical Strain Energy Harvester using 2D Black Phosphorus Nanosheets” published  by the journal ACS Energy Letters.

Source: https://news.vanderbilt.edu/

3D Printing Art And Design in Paris

Do you plan  to travel to Paris? In this case do not miss to visit the Centre Pompidou,  this huge museum, located in the center of Paris and dedicated to modern Art.  You can assist to  “Mutations/Créations“: a new event decidedly turned towards the future and the interaction between digital technology and creation; a territory shared by art, innovation and science.

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Drawing on all the disciplines in a mix of research, art and engineering, the first edition of this annual event calls upon music, design and architecture. It consists of two exhibitions (“Imprimer le monde“ and “Ross Lovegrove“), an Art/Innovation Forum entitled “Vertigo“, and various study days and get-togethers. Each year, thematic and monographic exhibitions will be staged around meetings and workshops that turn the Centre Pompidou into an “incubator“: a place for demonstrating prototypes, carrying out artistic experiments in vivo, and talking with designers. This platform will also be a critical observatory and a tool for analysing the impact of creation on society. How have the various forms of creation begun using digital technologies to open up new industrial perspectives? How do they question the social, economic and political effects of these industrial developments, and their ethical limits? What formal transformations have come about in music, art, design and architecture with regard to technical and scientific progress?


In the same space,  you can see a  new retrospective devoted to British designer Ross Lovegrove, which shows how the artist has introduced a fresh dialogue between nature and technology, where art and science converge. He employs a “holistic“ idea of design through a visionary practice that began incorporating digital changes during the 1990s, rejecting the productivism of mass industry and replacing it with a more economical approach to materials and forms. This exhibition emphasises the role of design in the postindustrial era, now that we are seeing a significant shift from mechanics to organics: a changeover symptomatic of our times, which these “digital forms“ endeavour to highlight.

Source: https://www.centrepompidou.fr/

Ultrafast Flexible Electronic Memory

Engineering experts from the University of Exeter (UK) have developed innovative new memory using a hybrid of graphene oxide and titanium oxide. Their devices are low cost and eco-friendly to produce, are also perfectly suited for use in flexible electronic devices such as ‘bendablemobile phone, computer and television screens, and even ‘intelligentclothing.
. Crucially, these devices may also have the potential to offer a cheaper and more adaptable alternative to ‘flash memory’, which is currently used in many common devices such as memory cards, graphics cards and USB computer drives. The research team insist that these innovative new devices have the potential to revolutionise not only how data is stored, but also take flexible electronics to a new age in terms of speed, efficiency and power.

bendable mobile phone

Using graphene oxide to produce memory devices has been reported before, but they were typically very large, slow, and aimed at the ‘cheap and cheerful’ end of the electronics goods market”, said Professor David Wright, an Electronic Engineering expert from the University of Exeter.

Our hybrid graphene oxide-titanium oxide memory is, in contrast, just 50 nanometres long and 8 nanometres thick and can be written to and read from in less than five nanoseconds – with one nanometre being one billionth of a metre and one nanosecond a billionth of a second.”

The research is published in the scientific journal ACS Nano.

Source: http://www.exeter.ac.uk/

‘Spray-On’ Memory for Paper, Fabric, Plastic

USB flash drives are already common accessories in offices and college campuses. But thanks to the rise in printable electronics, digital storage devices like these may soon be everywhere – including on our groceries, pill bottles and even clothingDuke University researchers have brought us closer to a future of low-cost, flexible electronics by creating a new “spray-on digital memory device using only an aerosol jet printer and nanoparticle inks. The device, which is analogous to a 4-bit flash drive, is the first fully-printed digital memory that would be suitable for practical use in simple electronics such as environmental sensors or RFID tags. And because it is jet-printed at relatively low temperatures, it could be used to build programmable electronic devices on bendable materials like paper, plastic or fabric.

PrintingMemory

Duke University researchers have developed a new “spray-on” digital memory (upper left) that could be used to build programmable electronics on flexible materials like paper, plastic or fabric. They used LEDS to demonstrate a simple application.

We have all of the parameters that would allow this to be used for a practical application, and we’ve even done our own little demonstration using LEDs,” said Duke graduate student Matthew Catenacci, who describes the device in a paper published online in the Journal of Electronic Materials. At the core of the new device, which is about the size of a postage stamp, is a new copper-nanowire-based printable material that is capable of storing digital information.

Memory is kind of an abstract thing, but essentially it is a series of ones and zeros which you can use to encode information,” said Benjamin Wiley, an associate professor of chemistry at Duke and an author on the paper.

Source: https://today.duke.edu/

Solar Nanotech-Powered Clothing

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

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.

back-to-the-future

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.

The research was published Nov. 11 in the academic journal Nature Communications.

Source: https://today.ucf.edu

How To Generate Wonderful Colors

Colors are produced in a variety of ways. The best known colors are pigments. However, the very bright colors of the blue tarantula or peacock feathers do not result from pigments, but from nanostructures that cause the reflected light waves to overlap. This produces extraordinarily dynamic color effects.

blue-tarantulaScientists from Karlsruhe Institute of Technology (KIT) in Germany, in cooperation with international colleagues, have now succeeded in replicating nanostructures that generate the same color irrespective of the viewing angle.

In contrast to pigments, structural colors are non-toxic, more vibrant and durable. In industrial production, however, pigments have the drawback of being strongly iridescent, which means that the color perceived depends on the viewing angle. An example is the rear side of a CD. Hence, such colors cannot be used for all applications. Bright colors of animals, by contrast, are often independent of the angle of view. Feathers of the kingfisher always appear blue, no matter from which angle we look. The reason lies in the nanostructures: While regular structures are iridescent, amorphous or irregular structures always produce the same color. Yet, industry can only produce regular nanostructures in an economically efficient way. Radwanul Hasan Siddique, researcher at KIT in collaboration with scientists from USA and Belgium has now discovered that the blue tarantula does not exhibit iridescence in spite of periodic structures on its hairs. First, their study revealed that the hairs are multi-layered, flower-like structure. Then, the researchers analyzed its reflection behavior with the help of computer simulations. In parallel, they built models of these structures using nano-3D printers and optimized the models with the help of the simulations. In the end, they produced a flower-like structure that generates the same color over a viewing angle of 160 degrees. This is the largest viewing angle of any synthetic structural color reached so far.

Apart from the multi-layered structure and rotational symmetry, it is the hierarchical structure from micro to nano that ensures homogeneous reflection intensity and prevents color changes. Via the size of the “flower,” the resulting color can be adjusted, which makes this coloring method interesting for industry. “This could be a key first step towards a future where structural colorants replace the toxic pigments currently used in textile, packaging, and cosmetic industries,” says Radwanul Hasan Siddique of KIT’s Institute of Microstructure Technology, who now works at the California Institute of Technology. He considers short-term application in textile industry feasible. Dr. Hendrik Hölscher thinks that the scalability of nano-3D printing is the biggest challenge on the way towards industrial use. Only few companies in the world are able to produce such prints.

Source: http://www.kit.edu

Adhesive Holds From Extreme Cold To Extreme Heat

Researchers from Case Western Reserve University, Dayton Air Force Research Laboratory and China have developed a new dry adhesive that bonds in extreme temperatures—a quality that could make the product ideal for space exploration and beyond.

The gecko-inspired adhesive loses no traction in temperatures as cold as liquid nitrogen or as hot as molten silver, and actually gets stickier as heat increases, the researchers report.

The research, which builds on earlier development of a single-sided dry adhesive tape based on vertically aligned carbon nanotubes, is published in the journal Nature Communications.

Liming Dai, professor of macromolecular science and engineering at Case Western Reserve and an author of the study teamed with Ming Xu, a senior research associate at Case School of Engineering and visiting scholar from Huazhong University of Science and Technology.

hanging

Ming Xu, senior research associate at Case Western Reserve, hangs from two wooden blocks held to a painted wall with six small pieces of the double-sided adhesive.

Vertically aligned carbon nanotubes with tops bundled into nodes replicate the microscopic hairs on the foot of the wall-walking reptile and remain stable from -320 degrees Fahrenheit to 1,832 degrees, the scientists say.

When you have aligned nanotubes with bundled tops penetrating into the cavities of the surface, you generate sufficient van der Waal’s forces to hold,” Xu said. “The dry adhesive doesn’t lose adhesion as it cools because the surface doesn’t change. But when you heat the surface, the surface becomes rougher, physically locking the nanotubes in place, leading to stronger adhesion as temperatures increase.”

Because the adhesive remains useful over such a wide range of temperatures, the inventors say it is ideally suited for use in space, where the shade can be frigid and exposure to the sun blazing hot.

In addition to range, the bonding agent offers properties that could add to its utility. The adhesive conducts heat and electricity, and these properties also increase with temperature. “When applied as a double-sided sticky tape, the adhesive can be used to link electrical components together and also for electrical and thermal management,”said Ajit Roy, of the Materials and Manufacturing Directorate, Air Force Research Laboratory.

This adhesive can thus be used as connecting materials to enhance the performance of electronics at high temperatures,” Dai comments. “At room temperature, the double-sided carbon nanotube tape held as strongly as commercial tape on various rough surfaces, including paper, wood, plastic films and painted walls, showing potential use as conducting adhesives in home appliances and wall-climbing robots.”

Source: http://thedaily.case.edu/

Self-healing Materials

A team of engineers at the University of California San Diego has developed a magnetic ink that can be used to make self-healing batteries, electrochemical sensors and wearable, textile-based electrical circuits. The key ingredient for the ink is microparticles oriented in a certain configuration by a magnetic field. Because of the way they’re oriented, particles on both sides of a tear are magnetically attracted to one another, causing a device printed with the ink to heal itself. The devices repair tears as wide as 3 millimeters—a record in the field of self-healing systems.

self-healing-wearable

Our work holds considerable promise for widespread practical applications for long-lasting printed electronic devices,” said Joseph Wang, director of the Center for Wearable Sensors and chair of the nanoengineering department at UC San Diego.

Existing self-healing materials require an external trigger to kick start the healing process. They also take anywhere between a few minutes to several days to work. By contrast, the system developed by Wang and colleagues doesn’t require any outside catalyst to work. Damage is repaired within about 50 milliseconds (0.05 seconds).

Engineers used the ink to print batteries, electrochemical sensors and wearable, textile-based electrical circuits. They then set about damaging these devices by cutting them and pulling them apart to create increasingly wide gaps. Researchers repeatedly damaged the devices nine times at the same location. They also inflicted damage in four different places on the same device. The devices still healed themselves and recovered their function while losing a minimum amount of conductivity.

For example, nanoengineers printed a self-healing circuit on the sleeve of a T-shirt and connected it with an LED light and a coin battery. The researchers then cut the circuit and the fabric it was printed on. At that point, the LED turned off. But then within a few seconds it started turning back on as the two sides of the circuit came together again and healed themselves, restoring conductivity.

Researchers detail their findings in the journal Science Advances.

Source: http://ucsdnews.ucsd.edu/

Diamond NanoThread, The New Wonder Material

Would you dress in diamond nanothreads? It’s not as far-fetched as you might think. And you’ll have a Brisbane-based carbon chemist and engineer to thank for it. QUT’s Dr Haifei Zhan is leading a global effort to work out how many ways humanity can use a newly-invented material with enormous potential – diamond nanothread (DNT). First created by Pennsylvania State University last year, one-dimensional DNT is similar to carbon nanotubes, hollow cylindrical tubes 10,000 times smaller than human hair, stronger than steel – but brittle.

diamond-nanothread

DNT, by comparison, is even thinner, incorporating kinks of hydrogen in the carbon’s hollow structure, called Stone-Wale (SW) transformation defects, which I’ve discovered reduces brittleness and adds flexibility,” said Dr Zhan, from QUT’s School of Chemistry, Physics and Mechanical Engineering.

That structure makes DNT a great candidate for a range of uses. It’s possible DNT may become as ubiquitous a plastic in the future, used in everything from clothing to cars.

DNT does not look like a rock diamond. Rather, its name refers to the way the carbon atoms are packed together, similar to diamond, giving it its phenomenal strength. Dr Zhan has been modelling the properties of DNT since it was invented, using large-scale molecular dynamics simulations and high-performance computing. He was the first to realise the SW defects were the key to DNT’s versatility.

While both carbon nanotubes and DNT have great potential, the more I model DNT properties, the more it looks to be a superior material,” Dr Zhan said. “The SW defects give DNT a flexibility that rigid carbon nanotubes can’t replicate – think of it as the difference between sewing with uncooked spaghetti and cooked spaghetti. “My simulations have shown that the SW defects act like hinges, connecting straight sections of DNT. And by changing the spacing of those defects, we can a change – or tune – the flexibility of the DNT.

That research is published in the peer-reviewed publication Nanoscale.

Source: https://www.qut.edu.au/