Posts belonging to Category nanofiber



Biomaterial To Replace Plastics And Reduce Pollution

An inexpensive biomaterial that can be used to sustainably replace plastic barrier coatings in packaging and many other applications has been developed by Penn State researchers, who predict its adoption would greatly reduce pollution. Completely compostable, the material — a polysaccharide polyelectrolyte complex — is comprised of nearly equal parts of treated cellulose pulp from wood or cotton, and chitosan, which is derived from chitin — the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is the mountains of leftover shells from lobsters, crabs and shrimp consumed by humans.

These environmentally friendly barrier coatings have numerous applications ranging from water-resistant paper, to coatings for ceiling tiles and wallboard, to food coatings to seal in freshness, according to lead researcher Jeffrey Catchmark, professor of agricultural and biological engineering, College of Agricultural Sciences.

In the research, paperboard coated with the biomaterial exhibited strong oil and water barrier properties. The coating also resisted toluene, heptane and salt solutions and exhibited improved wet and dry mechanical and water vapor barrier properties.

The material’s unexpected strong, insoluble adhesive properties are useful for packaging as well as other applications, such as better performing, fully natural wood-fiber composites for construction and even flooring,” Jeffrey Catchmark said. “And the technology has the potential to be incorporated into foods to reduce fat uptake during frying and maintain crispness. Since the coating is essentially fiber-based, it is a means of adding fiber to diets.”

Source: http://news.psu.edu/

How To Draw Electricity from the Bloodstream

Men build dams and huge turbines to turn the energy of waterfalls and tides into electricity. To produce hydropower on a much smaller scale, Chinese scientists have now developed a lightweight power generator based on carbon nanotube fibers suitable to convert even the energy of flowing blood in blood vessels into electricity.

For thousands of years, people have used the energy of flowing or falling water for their purposes, first to power mechanical engines such as watermills, then to generate electricity by exploiting height differences in the landscape or sea tides. Using naturally flowing water as a sustainable power source has the advantage that there are (almost) no dependencies on weather or daylight. Even flexible, minute power generators that make use of the flow of biological fluids are conceivable. How such a system could work is explained by a research team from Fudan University in Shanghai, China. Huisheng Peng and his co-workers have developed a fiber with a thickness of less than a millimeter that generates electrical power when surrounded by flowing saline solution—in a thin tube or even in a blood vessel.

The construction principle of the fiber is quite simple. An ordered array of carbon nanotubes was continuously wrapped around a polymeric core. Carbon nanotubes are well known to be electroactive and mechanically stable; they can be spun and aligned in sheets. In the as-prepared electroactive threads, the carbon nanotube sheets coated the fiber core with a thickness of less than half a micron. For power generation, the thread or “fiber-shaped fluidic nanogenerator” (FFNG), as the authors call it, was connected to electrodes and immersed into flowing water or simply repeatedly dipped into a saline solution. “The electricity was derived from the relative movement between the FFNG and the solution,” the scientists explained. According to the theory, an electrical double layer is created around the fiber, and then the flowing solution distorts the symmetrical charge distribution, generating an electricity gradient along the long axis.

The power output efficiency of this system was high. Compared with other types of miniature energy-harvesting devices, the FFNG was reported to show a superior power conversion efficiency of more than 20%. Other advantages are elasticity, tunability, lightweight, and one-dimensionality, thus offering prospects of exciting technological applications. The FFNG can be made stretchable just by spinning the sheets around an elastic fiber substrate. If woven into fabrics, wearable electronics become thus a very interesting option for FFNG application. Another exciting application is the harvesting of electrical energy from the bloodstream for medical applications. First tests with frog nerves proved to be successful.

The findings are published in  the journal Angewandte Chemie.

Source: http://newsroom.wiley.com/

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/

Solar Nanotechnology-based Desalination

A new desalination system has been developed that combines membrane distillation technology and light-harvesting nanophotonics. Called nanophotonics-enabled solar membrane distillation technology, or NESMD for short, the development has come from the Center for Nanotechnology Enabled Water Treatment (NEWT), based at Rice University. The system works whereby hot salt water is flowed across one side of a porous membrane and cold freshwater is flowed across the otherWater vapor is naturally drawn through the membrane from the hot to the cold side, and because the seawater doesn’t need to be boiled, the energy requirements are less than they would be for traditional distillation, according to the researchers. However, the energy costs are still significant because heat is continuously lost from the hot side of the membrane to the cold.

Unlike traditional membrane distillation, NESMD benefits from increasing efficiency with scale,” said Rice’s Naomi Halas, a corresponding author on the paper and the leader of NEWT‘s  nanophotonics research efforts. “It requires minimal pumping energy for optimal distillate conversion, and there are a number of ways we can further optimise the technology to make it more productive and efficient.

The distillation membrane in the chamber contained a specially designed top layer of carbon black nanoparticles infused into a porous polymer. The light-capturing nanoparticles heated the entire surface of the membrane when exposed to sunlight. A thin half-millimeter-thick layer of salt water flowed atop the carbon-black layer, and a cool freshwater stream flowed below.

Rice scientist and water treatment expert Qilin Li said the water production rate increased greatly by concentrating the sunlight: “The intensity got up 17.5 kilowatts per meter squared when a lens was used to concentrate sunlight by 25 times, and the water production increased to about 6 liters per meter squared per hour.”

In the PNAS study, researchers offered proof-of-concept results based on tests with an NESMD chamber about the size of three postage stamps and just a few millimeters thick.

Source: http://www.waterworld.com/

How To Repair Connections Between Nerve Cells

Carbon nanotubes exhibit interesting characteristics rendering them particularly suited to the construction of special hybrid devices – consisting of biological tissue and synthetic material – planned to re-establish connections between nerve cells, for instance at spinal level, lost on account of lesions or trauma. This is the result of a piece of research published on the scientific journal Nanomedicine: Nanotechnology, Biology, and Medicine conducted by a multi-disciplinary team comprising SISSA (International School for Advanced Studies), the University of Trieste, ELETTRA Sincrotrone and two Spanish institutions, Basque Foundation for Science and CIC BiomaGUNE. More specifically, researchers have investigated the possible effects on neurons of the interaction with carbon nanotubes. Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process. This result, which shows the extent to which the integration between nerve cells and these synthetic structures is stable and efficient, highlights the great potentialities of carbon nanotubes as innovative materials capable of facilitating neuronal regeneration or in order to create a kind of artificial bridge between groups of neurons whose connection has been interrupted. In vivo testing has actually already begun.

Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process

Interface systems, or, more in general, neuronal prostheses, that enable an effective re-establishment of these connections are under active investigation” explain Laura Ballerini (SISSA) and Maurizio Prato (UniTSCIC BiomaGUNE), coordinating the research project. “The perfect material to build these neural interfaces does not exist, yet the carbon nanotubes we are working on have already proved to have great potentialities. After all, nanomaterials currently represent our best hope for developing innovative strategies in the treatment of spinal cord injuries“. These nanomaterials are used both as scaffolds, a supportive framework for nerve cells, and as means of interfaces releasing those signals that empower nerve cells to communicate with each other.

Source: https://eurekalert.org/

Skin Regeneration

A small U.S. biotech has successfully regenerated skin and stimulated hair growth in pigs with burns and abrasions, paving the way for a scientific breakthrough that could lead to the regeneration of fully functional human skinSalt Lake City-based PolarityTE Inc‘s patented approach to tissue engineering is designed to use a patient’s own healthy tissue to re-grow human skin for the treatment of burns and wounds. Despite recent advances in reconstructive surgery, plastic surgeons cannot give burn victims what they require the most — their skin. Current approaches to treat serious burns are “severely limited” in their effectiveness and in some cases, are rather expensive, PolarityTE‘s founder and CEO Denver Lough said in an interview.

Epicel, a skin graft widely used in burn units that is sold by Cambridge, Massachusetts-based Vericel Corp, does not result in fully thick and functional skin — which is PolarityTE‘s objective.

“If clinically successful, the PolarityTE platform could deliver the first scientific breakthrough in wound healing and reconstructive surgery in nearly half a century,” said Lough, who served as senior plastic surgery resident at Johns Hopkins Hospital before creating PolarityTE last year.

“PolarityTE expects to begin a human trial later this year and the cell therapy could hit the market 12 to 18 months thereafter”.

PolarityTE conducted its pre-clinical study on wounded pigs at an animal facility in Utah. The use of therapy resulted in scar-less healing, growth of hair follicles, complete wound coverage and the progressive regeneration of all skin layers, the company said. As pig skin is more complex and robust than human skin, successful swine data is typically seen as a precursor to effectiveness in human trials.

The technology also has the potential to develop fully-functional tissues, including bone, muscle, cartilage and the liver, PolarityTE said.

Source: http://www.polarityte.com/
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http://www.reuters.com/

Harvest: How To Increase The Production By Up To 40%

Nanolabs, a company specialised in nanotechnology, has been able to increase the production of melons by up to 40% on a farm in Almeria (Spain), thanks to the installation of ASAR systems in the irrigation system of the farm.
In 2015, 30,000 kilos were harvested, while in the same period of 2016, this figure increased to 50,000 kilos; a 40% growth.
To achieve this, Nanolabs applies nanotechnology through its ASAR solution, which acts physically on water, emitting a quantum of energy that stimulates hydrogen bonds. As a result, these become more active, which translates into a better transport of nutrients to the crops and a significant improvement in the use of the nutrients present in the substrate. The increase in production has not been the only benefit of the project; it has also made it possible to improve the quality of the fruit and has reduced both the consumption of water for irrigation and the use of fertilisers and phytosanitary products by 20%.
For Javier Llanes, CEO of Nanolabs, “the dramatic increase in the melon production is just one example of the great benefits that nanotechnology can bring to the agricultural sector. At Nanolabs, we apply technology to promote sustainability and we work on innovative projects with impressive results in both production improvement and savings in water consumption.”

Source: http://www.freshplaza.com/

New Technique Identifies Cancer In Urine Or Blood

A team of researchers, led by Professor Yoon-Kyoung Cho of Life Science at UNIST  (South Korea) has recently developed a new technique that effectively identifies cancer-causing substances in the urine or blood.

In the study, Professor Yoon-Kyoung Cho of Life Science, a group leader at IBS Research Center for Soft and Living Matter (CSLM) presented an integrated centrifugal microfluidic platform (Exodisc), a device that isolates extracellular vesicles (EVs) from urine.  The research team expects that this may be potentially useful in clinical settings to test urinary EV-based biomarkers for cancer diagnostics.

Extracellular vesicles (EVs) are cell-derived nanovesicles (40-1000 nm in size), present in almost all types of body fluids, which play a vital role in intercellular communication and are involved in the transport of biological signals for regulating diverse cellular functions. Despite the increasing clinical importance of EVs as potential biomarkers in the diagnosis and prognosis of various diseases, current methods of EV isolation and analysis suffer from complicated procedures with long processing times. For instance, even ultracentrifugation (UC), the most commonly used method for EV isolation, requires time-consuming steps involving centrifugation and acquisition of large sample volumes, and the results suffer from low yield and purity.

To overcome these limitations, Professor Cho presented a new lab-on-a-disc platform for rapid, size-selective, and efficient isolation and analysis of nanoscale EVs from raw biological samples, such as cell-culture supernatant (CCS) or cancer-patient urine.

EXODISC

The Exodisc is compoased of two independent filteration units (20nm and 600nm in size) within a disk-shaped chip to enable the processing of two different samples simulateously,” says Hyun-Kyung Woo (Combined M.S./Ph.D. student of Natural Science), the first author of the study. “Upon spinning the disc, the urine sample is transferred through two integrated nanofilters, allowing for the enrichment of unirary EVs within the size range of 20 to 600 nm.”
Using Exodisc, it is possible to isolate EVs from raw samples within 30 minutes,” says Professor Cho. “The process of passing the filter through centrifugal force is automatically carried out, effectively recovering the enriched EVs.”

On-disc ELISA using urinary EVs isolated from bladder cancer patients showed high levels of CD9 and CD81 expression, suggesting that this method may be potentially useful in clinical settings to test urinary EV-based biomarkers for cancer diagnostics,” explains Vijaya Sunkara of Life Sciences, the co-first author.
The results of the study has been published in the February issue of ACS Nano journal.

Source: http://news.unist.ac.kr/

Nanofiber For Bullet Proof Vests

Harvard researchers have developed a lightweight, portable nanofiber fabrication device that could one day be used to dress wounds on a battlefield or dress shoppers in customizable fabrics. There are many ways to make nanofibers. These versatile materials — whose target applications include everything from tissue engineering to bullet proof vests — have been made using centrifugal force, capillary force, electric field, stretching, blowing, melting, and evaporation.

Each of these fabrication methods has pros and cons. For example, Rotary Jet-Spinning (RJS) and Immersion Rotary Jet-Spinning (iRJS) are novel manufacturing techniques developed in the Disease Biophysics Group at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering. Both RJS and iRJS dissolve polymers and proteins in a liquid solution and use centrifugal force or precipitation to elongate and solidify polymer jets into nanoscale fibers. These methods are great for producing large amounts of a range of materials – including DNA, nylon, and even Kevlar – but until now they haven’t been particularly portable.

The Disease Biophysics Group recently announced the development of a hand-held device that can quickly produce nanofibers with precise control over fiber orientation. Regulating fiber alignment and deposition is crucial when building nanofiber scaffolds that mimic highly aligned tissue in the body or designing point-of-use garments that fit a specific shape.

nanofiber

Our main goal for this research was to make a portable machine that you could use to achieve controllable deposition of nanofibers,” said Nina Sinatra, a graduate student in the Disease Biophysics Group and co-first author of the paper. “In order to develop this kind of point-and-shoot device, we needed a technique that could produce highly aligned fibers with a reasonably high throughput.

The new fabrication method, called pull spinning, uses a high-speed rotating bristle that dips into a polymer or protein reservoir and pulls a droplet from solution into a jet. The fiber travels in a spiral trajectory and solidifies before detaching from the bristle and moving toward a collector. Unlike other processes, which involve multiple manufacturing variables, pull spinning requires only one processing parameter — solution viscosity — to regulate nanofiber diameter. Minimal process parameters translate to ease of use and flexibility at the bench and, one day, in the field.

The research was published recently in Macromolecular Materials and Engineering.

Source: https://www.seas.harvard.edu/

Wooden SkyScrapers

High-rise wooden buildings, such as 14-storey apartment building “The Tree” in Norway, are altering city skylines in what the timber industry is heralding as a new era that will dent the supremacy of concrete and steel.

wooden skyscraper

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Situated on the Bergen waterfront, The Tree is the tallest wooden building in the world. The 52.8 metre high structure is one of a growing number of so-called Plyscrapers altering city skylines. The timber industry say it’s an environmental solution, as countries seek to reduce emissions.

It will never totally displace concrete and steel, but it’s definitely a part in our solution towards our struggle towards a CO2 neutral society,”  says Ole Herman Kleppe, Chief Project Manager.

The architects insist that fears of fire in such timber homes are groundless.  “These columns and these CLT panels they don’t burn. They’re so thick that they don’t burn. In addition, they are painted with fire resistant paint and the house is sprinkled so we have all possible ways to prevent a fire in the house. So actually, this is the safest house in Bergen regarding fire.” explains Kleppe.

The 14-storey structure is made of sustainable wood. But concrete makers dispute the idea that timber is greener, insisting that deforestation causes more CO2 emissions. The Tree’s structure isn’t entirely wooden.

It’s concrete on this roof because it adds weight and it was necessary to add weight to this wooden building because it kind of dampens the swinging,” adds Per Reigstad, architect at Artec.

Later this year a wooden building that’s two inches taller will open in Vancouver. Even taller structures are being planned in Vienna and London.

Source: http://www.reuters.com/

Bones Could Be 3D Printed With Unbreakable Materials

Scientists from Queen Mary University of London (QMUL) have discovered the secret behind the toughness of deer antlers and how they can resist breaking during fights.

3d-printed-bones

The fibrils that make up the antler are staggered rather than in line with each other. This allows them to absorb the energy from the impact of a clash during a fight,” said first author Paolino De Falco from QMUL‘s School of Engineering and Materials Science .

The research, published in the journal ACS Biomaterials Science & Engineering, provides new insights and fills a previous gap in the area of structural modelling of bone. It also opens up possibilities for the creation of a new generation of materials that can resist damage.

Co-author Dr Ettore Barbieri, also from QMUL‘s School of Engineering and Materials Science, comments: “Our next step is to create a 3D printed model with fibres arranged in staggered configuration and linked by an elastic interface. The aim is to prove that additive manufacturing – where a prototype can be created a layer at a time – can be used to create damage resistant composite material.”

Source: http://www.qmul.ac.uk/

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