New composite technology will see enhanced electrical and thermal conductivity of conventional composite materials

via Mega Composite Technology Co

New technology that could enhance both the electrical and thermal conductivity of conventional composite materials has been developed thanks to a collaboration between the University of Surrey, University of Bristol and aerospace company Bombardier.
  • New composite technology will see enhanced electrical and thermal conductivity of conventional composite materials which has previously been lacking
  • Novel functionality including sensors, energy harvesting lighting and communication antennae will now be integrated into the structure of the composite material
  • Technology will have wide-reaching benefits in the aerospace industry

Carbon fibre composites, composed of reinforcing carbon fibres within a plastic, have revolutionised industries that demand strong, yet light materials. However, their application has been hindered by inherently poor electrical and thermal conductivities.

New research, published in the journal Scientific Report, demonstrates that by growing nanomaterials, specifically carbon nanotubes, on the surface of the carbon fibres it is possible to impart these necessary properties.

The research, conducted at the University of Surrey’s Advanced Technology Institute (ATI) and the University of Bristol’s Advanced Composite Centre for Innovation and Science (ACCIS), shows off the potential of a carbon fibre reinforced plastic to be made multifunctional, while still maintaining its structural integrity. Novel functionality including sensors, energy harvesting lighting and communication antennae can now be integrated into the structure of the composite to usher in a new era in composite technology.

Professor Ravi Silva, Director of the ATI and Head of the Nanoelectronics Centre (NEC) said: “In the future, carbon nanotube modified carbon fibre composites could lead to exciting possibilities such as energy harvesting and storage structures with self-healing capabilities. We are currently working on such prototypes and have many ideas including the incorporation of current aerospace/satellite technology in automotive design.”

Dr Thomas Pozegic, Research Associate in ACCIS and formerly a PhD student at the University of Surrey, explained: “The aerospace industry still relies on metallic structures, in the form of a copper mesh, to provide lightning strike protection and prevent static charge accumulation on the upper surface of carbon fibre composites because of the poor electrical conductivity. This adds weight and makes fabrication with carbon fibre composites difficult. The material that we have developed utilises high-quality carbon nanotubes grown at a high density to allow electrical transport throughout the composite material.”

Dr Ian Hamerton, Reader in Polymers and Composite Materials in ACCIS, commented: “The research has shown that carbon nanotubes can significantly enhance the thermal conductivity of carbon fibre composites. This will have wide-reaching benefits in the aerospace industry, from enhancing de-icing solutions to minimising the formation of fuel vapours at cruising altitudes.”

Learn more: Electrifying news . . . nano-modified aerospace composites

 

 

Receive an email update when we add a new COMPOSITE MATERIALS article.

 

The Latest on: Composite technology

via  Bing News

 

3-D full-color holographic images with nanomaterials for 3D floating displays and more

via Missouri University of Science and Technology

via Missouri University of Science and Technology

Researchers at Missouri University of Science and Technology are creating a new approach to reconstruct 3-D full-color holographic images by using just one layer of nanoscale metallic film. This work has a huge potential to change our daily lives by equipping our cell phones with 3-D floating displays and printing 3-D security marking onto credit cards.

Dr. Xiaodong Yang, an assistant professor in mechanical and aerospace engineering at Missouri S&T, and Dr. Jie Gao, an assistant professor of mechanical and aerospace engineering at Missouri S&T, describe their ultrathin full-color holograms in “ACS Nano.” And they illustrate their approach by reproducing several full-color holographic images with nanometer-scale aluminum thin films. A nanometer is one billionth of a meter, and some nanomaterials are only a few atoms in size.

The method described in the “ACS Nano” article “Full-Color Plasmonic Metasurface Holograms” involves the use of ultrathin nanometer-scale metallic films with metasurfaces that can manipulate the wavefront of light. The researchers’ metasurface hologram is one 35-nanometer thick aluminum film punctured with tiny rectangular holes of 160 nanometers by 80 nanometers with different orientation angles created by a microfabrication process known as focused ion beam milling.

Experimenting with the interplay of red, green and blue laser light on metasurface structures, the researchers demonstrated “clean and vivid full-color holographic images with high resolution and low noise.” The three primary colors — red, green and blue — were produced, and the secondary colors of cyan, magenta, yellow and white also were produced. To illustrate their reconstructed holographic images, they made “CMYW” letters, an apple and a Rubik’ cube. They believe the metasurface hologram holds promise for future applications, such as credit card security marking, biomedical imaging, 3-D floating displays and big-data storage.

“By adjusting the orientation angle of the nanoscale slits, we are able to fully tune the phase delay through the slit for realizing the phase modulation within the entire visible color range,” says Yang. “In addition, the amplitude modulation is achieved by simply including or not including the slit. Our holograms contain both amplitude and phase modulations at nanometer scale so that high resolution and low noise holographic images can be reconstructed.”

The researchers created the metasurface hologram by drilling out tiny rectangular slits with various orientation angles through the aluminum thin layer. Under a scanning electron microscope, the hologram looks like a needlepoint pattern.

“Different from the currently existing metasurface holograms which are mostly designed for limited colors, our wavelength-multiplexed method — by encoding additional phase shifts into the holograms and introducing tilted incident angle illumination of laser light — results in the successful reconstruction of almost all visible colors,” says Gao, co-author of the paper.

Learn more: Researchers create 3-D full-color holographic images with nanomaterials

 

 

The Latest on: 3-D full-color holographic images

via  Bing News

 

Printing nanomaterials with plasma onto a 3-D object or flexible surface, such as paper or cloth

The nozzle firing a jet of carbon nanotubes with helium plasma off and on. When the plasma is off, the density of carbon nanotubes is small. The plasma focuses the nanotubes onto the substrate with high density and good adhesion. CREDIT NASA Ames Research Center

The nozzle firing a jet of carbon nanotubes with helium plasma off and on. When the plasma is off, the density of carbon nanotubes is small. The plasma focuses the nanotubes onto the substrate with high density and good adhesion.
CREDIT
NASA Ames Research Center

New method can deposit nanomaterials onto flexible surfaces and 3-D objects

Printing has come a long way since the days of Johannes Gutenberg. Now, researchers have developed a new method that uses plasma to print nanomaterials onto a 3-D object or flexible surface, such as paper or cloth. The technique could make it easier and cheaper to build devices like wearable chemical and biological sensors, flexible memory devices and batteries, and integrated circuits.

One of the most common methods to deposit nanomaterials–such as a layer of nanoparticles or nanotubes–onto a surface is with an inkjet printer similar to an ordinary printer found in an office. Although they use well-established technology and are relatively cheap, inkjet printers have limitations. They can’t print on textiles or other flexible materials, let alone 3-D objects. They also must print liquid ink, and not all materials are easily made into a liquid.

Some nanomaterials can be printed using aerosol printing techniques. But the material must be heated several hundreds of degrees to consolidate into a thin and smooth film. The extra step is impossible for printing on cloth or other materials that can burn, and means higher cost for the materials that can take the heat.

The plasma method skips this heating step and works at temperatures not much warmer than 40 degrees Celsius. “You can use it to deposit things on paper, plastic, cotton, or any kind of textile,” said Meyya Meyyappan of NASA Ames Research Center. “It’s ideal for soft substrates.” It also doesn’t require the printing material to be liquid.

The researchers, from NASA Ames and SLAC National Accelerator Laboratory, describe their work in Applied Physics Letters, from AIP Publishing>.

They demonstrated their technique by printing a layer of carbon nanotubes on paper. They mixed the nanotubes into a plasma of helium ions, which they then blasted through a nozzle and onto paper. The plasma focuses the nanoparticles onto the paper surface, forming a consolidated layer without any need for additional heating.

The team printed two simple chemical and biological sensors. The presence of certain molecules can change the electrical resistance of the carbon nanotubes. By measuring this change, the device can identify and determine the concentration of the molecule. The researchers made a chemical sensor that detects ammonia gas and a biological sensor that detects dopamine, a molecule linked to disorders like Parkinson’s disease and epilepsy.

But these were just simple proofs-of-principle, Meyyappan said. “There’s a wide range of biosensing applications.” For example, you can make sensors that monitor health biomarkers like cholesterol, or food-borne pathogens like E. coli and Salmonella.

Because the method uses a simple nozzle, it’s versatile and can be easily scaled up. For example, a system could have many nozzles like a showerhead, allowing it to print on large areas. Or, the nozzle could act like a hose, free to spray nanomaterials on the surfaces of 3-D objects.

“It can do things inkjet printing cannot do,” Meyyappan said. “But anything inkjet printing can do, it can be pretty competitive.”

The method is ready for commercialization, Meyyappan said, and should be relatively inexpensive and straightforward to develop. Right now, the researchers are designing the technique to print other kinds of materials such as copper. They can then print materials used for batteries onto thin sheets of metal such as aluminum. The sheet can then be rolled into tiny batteries for cellphones or other devices.

Learn more: Printing nanomaterials with plasma

 

 

The Latest on: Printing nanomaterials

via  Bing News

 

Mechanical Properties of Nanomaterials Can Be Altered Due to Electric Field

TeYu Chien, a UW assistant professor in the Department of Physics and Astronomy, uses a low-temperature scanning tunneling microscope in his lab to observe nanomaterials. Chien is the lead author of a paper that appears in the journal Scientific Reports. His research determined that the electric field is responsible for the alteration of the fracture toughness of nanomaterials, which are used in state-of-the-art electronic devices. (UW Photo)

TeYu Chien, a UW assistant professor in the Department of Physics and Astronomy, uses a low-temperature scanning tunneling microscope in his lab to observe nanomaterials. Chien is the lead author of a paper that appears in the journal Scientific Reports. His research determined that the electric field is responsible for the alteration of the fracture toughness of nanomaterials, which are used in state-of-the-art electronic devices. (UW Photo)

Mechanical properties of nanomaterials can be altered due to the application of voltage, University of Wyoming researchers have discovered.

The researchers, led by TeYu Chien, a UW assistant professor in the Department of Physics and Astronomy, determined that the electric field is responsible for altering the fracture toughness of nanomaterials, which are used in state-of-the-art electronic devices. It is the first observed evidence that the electric field changes the fracture toughness at a nanometer scale.

This finding opens the way for further investigation of nanomaterials regarding electric field-mechanical property interactions, which is extremely important for applications and fundamental research.

Chien is the lead author of a paper, titled “Built-in Electric Field Induced Mechanical Property Change at the Lanthanum Nickelate/Nb-doped Strontium Titanate Interfaces,” that was recently published in Scientific Reports. Scientific Reports is an online, open-access journal from the publishers of Nature. The journal publishes scientifically valid primary research from all areas of the natural and clinical sciences.

Other researchers who contributed to the paper are from the University of Arkansas, University of Tennessee and Argonne National Laboratory in Argonne, Ill.

Chien and his research team studied the surfaces of the fractured interfaces of ceramic materials, including lanthanum nickelate and strontium titanate with a small amount of niobium. The researchers revealed that strontium titanate, within a few nanometers of the interfaces, fractured differently from the strontium titanate away from the interfaces.

The two ceramic materials were chosen because one is a metallic oxide while the other is a semiconductor. When the two types of materials come into contact with each other, an intrinsic electric field will automatically be formed in a region, known as the Schottky barrier, near the interface, Chien explains. The Schottky barrier refers to the region where an intrinsic electric field is formed at metal/semiconductor interfaces.

The intrinsic electric field at interfaces is an inevitable phenomenon whenever one material is in contact with another. The electric field effects on the mechanical properties of materials are rarely studied, especially for nanomaterials. Understanding electric field effects is extremely important for applications of nanoelectromechanical system (NEMS), which are devices, such as actuators, integrating electrical and mechanical functionalities on the nanoscale.

For NEMS materials made in nanoscale, understanding the mechanical properties affected by electric fields is crucial for full control of device performance. The observations in this study pave the way to better understand the mechanical properties of nanomaterials.

“The electric field changes the inter-atomic bond length in the crystal by pushing positively and negatively charged ions in opposite directions,” Chien says. “Altering bond length changes bond strength. Hence, the mechanical properties, such as fracture toughness.”

“The whole picture is this: The intrinsic electric field in the Schottky barrier was created at the interfaces. This then polarized the materials near the interfaces by changing the atomic positions in the crystal. The changed atomic positions altered the inter-atomic bond length inside the materials to change the mechanical properties near the interfaces,” Chien summarizes.

Read more: Mechanical Properties of Nanomaterials Are Altered Due to Electric Field, UW Researchers Find

 

 

The Latest on: Mechanical properties of nanomaterials

via  Bing News

 

Shaking the nanomaterials out

Nano implies small -- and that's great for use in medical devices, beauty products and smartphones -- but it's also a problem. All these tiny particles get into our water and are difficult to remove. Now, researchers Yoke Khin Yap and Dongyang Zhang have a novel and very simple way to take the nanomaterials out. CREDIT Michigan Tech, Sarah Bird

Nano implies small — and that’s great for use in medical devices, beauty products and smartphones — but it’s also a problem. All these tiny particles get into our water and are difficult to remove. Now, researchers Yoke Khin Yap and Dongyang Zhang have a novel and very simple way to take the nanomaterials out.
CREDIT
Michigan Tech, Sarah Bird

New method to purify contaminated water

Purifying water and greening nanotechnology could be as simple as shaking a vial of water and oil. At least that’s the case for a new method to clean contaminated water full of unwanted nanomaterials.

Nano implies small–and that’s great for use in medical devices, beauty products and smartphones–but it’s also a problem. The tiny nanoparticles, nanowires, nanotubes and other nanomaterials that make up our technology eventually find their way into water. The Environmental Protection Agency says more 1,300 commercial products use some kind of nanomaterial. And we just don’t know the full impact on health and the environment.

“These materials are very, very tiny and that means if you try to remove them and clean them out of contaminated water, that it’s quite difficult,” says Dongyan Zhang, a research scientist at Michigan Technological University. She adds that techniques like filter paper or meshes often don’t work.

Instead, shaking up oil and water traps the nanomaterials, which can be easily removed. The process clears out nearly 100 percent of nanowires, nanosheets, nanotubes and other one- and two-dimensional nanomaterials. Only zero-dimensional nanospheres are still too small to grab.

Read more: Shaking the nanomaterials out

 

 

The Latest on: Nanomaterial contaminated water

via  Bing News