#New composite protects from corrosion at high mechanical stress (Nanowerk News) Material researchers at the INM Leibniz Institute for New Materials will be presenting a composite material
which prevents metal corrosion in an environmentally friendly way, even under extreme conditions. It can be used wherever metals are exposed to severe weather conditions, aggressive gases,
media containing salt, heavy wear or high pressures. The INM from Saarbrcken will be one of the few German research institutions at the Techconnect World trade fair on 15 and 16 june in WASHINGTON DC, USA,
where it will be presenting this and other results. Working in cooperation with the VDI Association of German Engineers it will be showcasing its latest developments at Stand 301 in the German Area.
New composite protects from corrosion at high mechanical stress. This patented composite exhibits its action by spray application,
explains Carsten Becker-Willinger, Head of the Nanomers Program Division. The key is the structuring of this layer-the protective particles arrange themselves like roof tiles.
As in a wall, several layers of particles are placed on top of each other in an offset arrangement;
highly structured barrier, says the chemical nanotechnology expert. The protective layer is just a few micrometers thick
and prevents penetration by gases and electrolytes. It provides protection against corrosion caused by aggressive aqueous solutions,
or aqueous acids such as acid rain. The protective layer is an effective barrier, even against corrosive gases or under pressure.
the composite adheres to the metal substrate, is abrasion-stable and impact-resistant. As a result, it can withstand high mechanical stress.
The coating passes the falling ball test with a steel hemispherical ball weighing 1. 5 kg from a height of one meter without chipping
or breaking and exhibits only slight deformation, which means that the new material can be used even in the presence of sand or mineral dust without wear and tear.
The composite can be applied by spraying or other commonly used wet chemistry processes and cures at 150-200c.
It is suitable for steels, metal alloys and metals such as aluminum, magnesium and copper, and can be used to coat any shape of plates, pipes, gear wheels, tools or machine parts.
The specially formulated mixture contains a solvent, a binder and nanoscale and platelet-like particles;
it does not contain chromium VI or other heavy metals. INM conducts research and development to create new materials for today, tomorrow and beyond.
Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new,
how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM:
New materials for energy application, new concepts for medical surfaces, new surface materials for tribological systems and nano safety and nano bio.
Nanocomposite Technology, Interface Materials, and Bio Interfaces s
#Transient melting of a nanocrystal: seeing is believing (Nanowerk News) Jesse Clark, working as a postdoc in the LCN group of Ian Robinson,
has discovered a spectacular transient melting phenomenon in nanocrystals. Coherent X-ray diffraction experiments, carried out at the LCLS X-ray free electron laser facility at Stanford,
have allowed snapshot imaging of a single 300 nm gold nanocrystal in the picosecond time interval after the particle was excited with a laser.
The crystal was found to expand uniformly following the excitation and to reach the melting point about 50 ps later("Imaging transient melting of a nanocrystal using an X-ray laser").
"What is striking about the result, shown in the figure, is that the crystal melts from the outside
and then re-solidifies in synchrony with the induced acoustic vibrations. Imaging transient melting of a nanocrystal using an x-ray laser.
Snapshot projection images of a gold nanocrystal, 300nm across, before and after excitation with a femtosecond laser.
The second image, 50 picoseconds after excitation, displays a low density skin that returns to the original density at later times This result has significant implications beyond our basic understanding of the melting process.
A reproducible molten state of a metal such as platinum could have useful catalytic properties while preserving the integrity and large surface area of the particle.
Ian Robinson, coordinator of the project said"Bragg Coherent Diffraction Imaging is an emerging X-ray technique with great potential for probing the dynamics of matter.
The dynamic imaging of the melting transition, visualised in this work, anticipates a whole new field of materials science in the time domain.
"The work was supported by a European Research Council Advanced grant entitled"nanosculpture
#Team develops transplantable bioengineered forelimb in an animal model (w/video) A team of Massachusetts General Hospital (MGH) investigators has made the first steps towards development of bioartificial replacement limbs suitable for transplantation.
In their report, which has been published online in the journal Biomaterials("Engineered composite tissue as a bioartificial limb graft),
"the researchers describe using an experimental approach previously used to build bioartificial organs to engineer rat forelimbs with functioning vascular and muscle tissue.
"The composite nature of our limbs makes building a functional biological replacement particularly challenging, "explains Harald Ott, MD, of the MGH Department of Surgery and the Center for Regenerative medicine, senior author of the paper."
"Limbs contain muscles, bone, cartilage, blood vessels, tendons, ligaments and nerves-each of which has to be rebuilt
Over the past two decades a number of patients have received donor hand transplants, and while such procedures can significantly improve quality of life,
they also expose recipients to the risks of lifelong immunosuppressive therapy. While the progenitor cells needed to regenerate all of the tissues that make up a limb could be provided by the potential recipient
The current study uses technology Ott discovered as a research fellow at the University of Minnesota, in
The research team then cultured the forelimb matrix in a bioreactor, within which vascular cells were injected into the limb's main artery to regenerate veins and arteries.
and after two weeks, the grafts were removed from the bioreactor. Analysis of the bioartificial limbs confirmed the presence of vascular cells along blood vessel walls
and muscle cells aligned into appropriate fibers throughout the muscle matrix. Functional testing of the isolated limbs showed that electrical stimulation of muscle fibers caused them to contract with a strength 80 percent of
what would be seen in newborn animals. The vascular systems of bioengineered forelimbs transplanted into recipient animals quickly filled with blood
the experience of patients who have received hand transplants is promising.""In clinical limb transplantation, nerves do grow back into the graft, enabling both motion and sensation,
We hope in future work to show that the same will apply to bioartificial grafts.
#Surface-modified nanoparticles endow coatings with combined properties Fabricators and processors alike demand consistently high quality for their intermediate and final products.
The properties of these goods usually also have to meet specific requirements. Particularly the surfaces of workpieces or mouldings are expected to exhibit several different functions at one and the same time,
The INM Leibniz Institute for New Materials uses nanoparticles as design element for such multifunctional coatings.
These nanoparticles are adapted specifically to the particular application by Small Molecule Surface Modification (SMSM. How this approach can be used to produce custom-tailored coatings will be demonstrated at the Techconnect World trade fair on 15 and 16 june in WASHINGTON DC, USA,
the nanoparticles used can be modified surface with organic moieties. Small Molecule Surface Modification (SMSM) bestows specific combinations of desired properties, for example hydrophilic, hydrophobic, adhesive, anti-adhesive
Nanoparticles thus modified are used to develop nanocomposites: they combine the physical solid-state properties of e g. ceramics or semiconductors with classic polymer-processing technology.
Titanium dioxide, barium titanate, indium-tin oxide or zirconium dioxide, for instance, are used as nanoparticles. In addition to the chemical intrinsic composition of the nanoparticles and their SMSM surface treatment, the properties that are attainable for the desired coatings also vary with the size and dispersal mode of the nanoparticles.
INM composite systems are produced via wet-chemical processes. The modified nanoparticles and additives combine with a polymer matrix (an epoxy resin, an acrylate,
a polyimide for example) or a hybrid matrix (organic-inorganic) to produce a coatable Nanomer composite system. he modular principle makes it possible to achieve a number of properties at one
and the same time in one material, explains Carsten Becker-Willinger, head of the program division Nanomers,
t helps us to respond in a highly systematic way to the different needs of industry,
the chemist summarizes the potential of nanocomposite technology. Read more: Surface-modified nanoparticles endow coatings with combined propertie e
#Nano-spirals could guard against identity theft (Nanowerk News) Take gold spirals about the size of a dimeand shrink them down about six million times.
if they were added to identity cards, currency and other important objects. Students and faculty at Vanderbilt University fabricated these tiny Archimedes spirals and then used ultrafast lasers at Vanderbilt and the Pacific Northwest National Laboratory in Richland, Washington,
to characterize their optical properties. The results are reported in a paper published online by the Journal of Nanophotonics("Efflcient forward second-harmonic generation from planar archimedean nanospirals".
"Scanning electron microscope image of an individual nano-spiral. Image: Haglund Lab/Vanderbilt) They are certainly smaller than any of the spirals weve found reported in the scientific literature,
the Vanderbilt doctoral student who figured out how to study their optical behavior. The spirals were designed
and made at Vanderbilt by another doctoral student, Jed Ziegler, now at the Naval Research Laboratory.
Most other investigators who have studied the remarkable properties of microscopic spirals have done so by arranging discrete nanoparticles in a spiral pattern:
A number of crystals produce this effect, called frequency doubling or harmonic generation, to various degrees.
The strongest frequency doubler previously known is the synthetic crystal beta barium borate, but the nano-spirals produce four times more blue light per unit volume.
When infrared laser light strikes the tiny spirals it is absorbed by electrons in the gold arms.
Electrons that are driven toward the center absorb enough energy so that some of them emit blue light at double the frequency of the incoming infrared light.
said Stevenson Professor of Physics Richard Haglund, who directed the research. If you bow a violin string very lightly it produces a single tone.
The electrons at the center of the spirals are driven pretty vigorously by the lasers electric field.
Computer simulation of the harmonic emissions produced by a nano-spiral when it is being illuminated by infrared light.
Because of the tiny quantities of metal actually used, they can be made inexpensively out of precious metals,
If nano-spirals were embedded in a credit card or identification card, they could be detected by a device comparable to a barcode readerif nano-spirals were embedded in a credit card or identification card,
they could be detected by a device comparable to a barcode reader, said Haglund. The frequency doubling effect is strong enough
. and a team of engineers at the Wyss Institute for Biologically Inspired Engineering and Harvard John A. Paulson School of engineering and Applied sciences (SEAS) could some day help people suffering from loss of hand motor control to regain some of their daily
Soft, multisegment actuators used in the soft robotic glove enable an assistive range of motions alike those performed by the biological fingers and thumb.
The actuators are customizable to accommodate each patient's specific hand size and pathology. Image:
picking up a telephone, or using cooking and eating utensils, become frustrating and nearly impossible feats due to reduced gripping strength and motor control in the hand.
The stage is now set for that to change, however, thanks to soft, wearable robotic systems and the Wyss Institute's"from bench to bedside"translational approach that has enabled the glove's potential end users to be involved in every step of testing and development.
The holistic approach ensures that technology development goes beyond achieving functionality to also incorporate social and psychological elements of design that promote translation and seamless adoption by its intended end users."
"From the start of this project, we've focused on understanding the realworld challenges facing these patients by visiting them in their homes to perform research,
who is a Wyss Institute Core Faculty member, Founder of the Harvard Biodesign Lab, and Assistant professor of Mechanical and Biomedical engineering AT SEAS.
A team of undergraduate students also contributed to an early glove design as part of his ES227 Medical device Design Course.
Wyss Technology Development Fellow Panagiotis Polygerinos, Ph d, . and Wyss Mechanical engineer Kevin Galloway, Ph d. incorporated the patients'feedback at every stage of development of the glove in an effort to maximize its potential for translation."
which could help patients suffering from muscular dystrophy, amyotrophic lateral sclerosis (ALS), incomplete spinal cord injury, or other hand impairments to regain some daily independence and control of their environment.
Walsh's team adapted the mechanics of the glove to make it more comfortable and natural feeling to wearers.
which are composite tubular constructions of Kevlar fibers and silicone elastomer, support the range of motions performed by biological fingers.
The glove's control system is portable and lightweight and can be worn using a waist belt
or can be attached to a wheelchair. Now, the team is working to improve on their glove control strategies that will allow the system to detect the intent of the wearer.
One potential solution is to leverage surface electromyography using small electrical sensors in a cuff worn around the patient's forearm.
The electromyography sensors-which could be used to directly control the glove work by detecting the residual muscle signals fired by motor neurons
in relation to making it customizable for the specific pathologies of each individual and understanding what control strategies work best
"For patients suffering from muscular dystrophy, amyotrophic lateral sclerosis (ALS), and incomplete spinal cord injury, the soft robotic glove could allow them to regain some of their daily independence through robotic gloveassisted hand functions.
Walsh and his team have also been aided in their work through key expertise from two other Wyss Core Faculty members George Whitesides, Ph d,
. who is also the Woodford L. and Ann A. Flowers University Professor at Harvard, and Robert Wood, Ph d.,who is also the Charles river Professor of Engineering and Applied sciences AT SEAS.
The design of the glove has been published in Robotics and Autonomous Systems journal("Soft robotic glove for combined assistance and at home rehabilitation")and the team also recently presented it at the International Conference on Robotics and Automation.
This August, the team's electromyography control work will be presented at the International Conference on Robotics Research,
Down the road, the team is interested in developing the glove beyond an assistive device to a rehabilitation tool for various hand pathologies,
"Science benefits from an environment that allows access to valuable insights that can only be gained by working with actual potential end users of a developing technology,
. who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical school and Boston Children's Hospital and Professor of Bioengineering AT SEAS."
#A universal transition Understanding what causes materials to change from electrical insulators to metallic conductors is relevant not only to the development of practical electronic devices,
It also has a number of unusual properties owing to the relationship between some of its energy states and its crystal structure.
which half of the electronic states that can contribute to the material electrical conductivity are occupied by electrons,
because electrons can freely travel around by moving in and out of the empty sites. In this organic material,
and form valence bonds. The only way for electrons to break free is to forcefully add additional electrical charge to the system,
Therefore, rather than relying solely on electrical conductivity measurements, the researchers combined these observations with thermoelectric power measurements,
The experimental data clarified previous conflicting experimental results and revealed that the Mott transition belongs to a universal class of phase transitions.
a solid material with spin-transition solution-like behaviour Spintronics is called a discipline to change the way we store
and manage digital information by using the spin of electrons. Metal complexes showing spin-transition (i e. reversible interconversion between different isomers) are among the best candidates for the preparation of molecular memories and spintronic devices.
A major bottleneck for the use of these compounds in such high-added value applications is however the lack of reliable methodologies for their integration into solid materials,
Although some successful examples of the incorporation of these complexes into micro/nanoparticles and liquids crystals have been reported during the last years,
#Next-generation illumination using silicon quantum dot-based white-blue LED (Nanowerk News) A silicon quantum dot (QD)- based hybrid inorganic/organic light-emitting diode (LED) that exhibits white-blue electroluminescence
has been fabricated by Professor Ken-ichi SAITOW (Natural science Center for Basic Research and development, Hiroshima University), Graduate student Yunzi XIN (Graduate school of Science, Hiroshima University),
and their collaborators (Applied Physics Letters,"White-blue electroluminescence from a Si quantum dot hybrid light-emitting diode").
"Professor Ken-ichi Saitow, Natural science Center for Basic Research and development, Hiroshima University and Graduate student Yunzi Xin, Graduate school of Science, Hiroshima University, have fabricated an Si QD hybrid LED.
A hybrid LED is expected to be a next-generation illumination device for producing flexible lighting and display,
and this is achieved for the Si QD-based white-blue LED. The Si QD hybrid LED was developed using a simple method;
almost all processes were based solution and conducted at ambient temperature and pressure. Conductive polymer solutions and a colloidal Si QD solution were deposited on the glass substrate.
The current and optical power densities of the LED are, respectively, 280 and 350 times greater than those reported previously for such a device at the same voltage (6 V). In addition,
the active area of the LED is 4 mm2, which is 40 times larger than that of a typical commercial LED;
the thickness of the LED is 0. 5 mm. Professor Saitow stated,"QD LED has attracted significant attention as a next-generation LED.
Although several breakthroughs will be required for achieving implementation, a QD-based hybrid LED allows us to give so fruitful feature that we cannot imagine."
"Regarding quantum dots: Semiconductor QDS can produce full-color luminescence through tuning of the particle size.
QDS have attracted significant attention as potential components of next-generation solid-state light sources, including LEDS s
#Researchers design the most precise quantum thermometer to date (Nanowerk News) Physics at the UAB have found the formula to construct a quantum thermometer with enough precision to detect minute fluctuations in temperature in regions as small as the inside of a cell.
The research appears today in the journal Physical Review Letters("Individual quantum probes for optimal thermometry".
"Researchers from the UAB and the University of Nottingham, in an article published today in Physical Review Letters,
have fixed the limits of thermometry, i e.,, they have established the smallest possible fluctuation in temperature which can be measured.
The researchers have studied the sensitivity of thermometers created with a handful of atoms, small enough to be capable of showing typical quantum-style behaviours.
For the authors of the research, finding a nanothermometer sensitive enough at this scale is a great step forward in the field of nanotechnology, with applications in biology, chemistry, physics and even in the diagnosis and treatment of diseases s
#Injectable nanoelectronics for treatment of neurodegenerative diseases It's a notion that might be pulled from the pages of science-fiction novel-electronic devices that can be injected directly into the brain,
and treat everything from neurodegenerative disorders to paralysis. It sounds unlikely, until you visit Charles Lieber's lab. A team of international researchers, led by Lieber, the Mark Hyman, Jr.
Professor of Chemistry, an international team of researchers developed a method for fabricating nanoscale electronic scaffolds that can be injected via syringe.
Once connected to electronic devices, the scaffolds can be used to monitor neural activity, stimulate tissues and even promote regenerations of neurons.
The study is described in a June 8 paper in Nature Nanotechnology("Syringe-injectable electronics"."Contributing to the work were Jia Liu, Tian-Ming Fu, Zengguang Cheng, Guosong Hong, Tao Zhou, Lihua Jin, Madhavi Duvvuri, Zhe Jiang, Peter
Kruskal, Chong Xie, Zhigang Suo, Ying Fang.""I do feel that this has the potential to be said revolutionary,
"This opens up a completely new frontier where we can explore the interface between electronic structures and biology.
but no one has addressed this issue-the electronics/cellular interface-at the level at which biology works."
"The idea of merging the biological with the electronic is not a new one for Lieber.
When releasing the electronics scaffold completely from the fabrication substrate, we noticed that it was almost invisible and very flexible like a polymer
and could literally be sucked into a glass needle or pipette. From there, we simply asked, would it be possible to deliver the mesh electronics by syringe needle injection,
a process common to delivery of many species in biology and medicine-you could go to the doctor
and you inject this and you're wired up.'"'"Though not the first attempts at implanting electronics into the brain-deep brain stimulation has been used to treat a variety of disorders for decades-the nano-fabricated scaffolds operate on a completely different scale.
Zhe Jiang, Peter Kruskal, Chong Xie, Zhigang Suo, Ying Fang"Existing techniques are crude relative to the way the brain is wired,
"Whether it's a silicon probe or flexible polymers...they cause inflammation in the tissue that requires periodically changing the position or the stimulation.
But with our injectable electronics, it's as if it's not there at all. They are one million times more flexible than any state-of-the-art flexible electronics
and have subcellular feature sizes. They're what I call"neuro-philic"-they actually like to interact with neurons.."
The process is used similar to that to etch microchips, and begins with a dissolvable layer deposited on a substrate.
researchers lay out a mesh of nanowires sandwiched in layers of organic polymer. The first layer is dissolved then, leaving the flexible mesh,
which can be drawn into a syringe needle and administered like any other injection. After injection, the input/output of the mesh can be connected to standard measurement electronics
so that the integrated devices can be addressed and used to stimulate or record neural activity.""These type of things have never been done before, from both a fundamental neuroscience and medical perspective,
"Lieber said.""It's really exciting-there are a lot of potential applications.""Going forward, Lieber said, researchers hope to better understand how the brain
and other tissues react to the injectable electronics over longer periods. Harvard's Office of Technology Development has filed for a provisional patent on the technology
and is actively seeking commercialization opportunities.""Having those results can prove that this is really a viable technology,
"Lieber said.""The idea of being able to precisely position and record from very specific areas,
#Researchers build world's first fully functioning single crystal waveguide in glass Researchers from Lehigh University,
Japan and Canada have advanced a step closer to the dream of all-optical data transmission by building
and demonstrating what they call the"world's first fully functioning single crystal waveguide in glass."
"In an article published in Scientific Reports("Direct laser-writing of ferroelectric single-crystal waveguide architectures in glass for 3d integrated optics),
"the group said it had employed ultrafast femtosecond lasers to produce a three-dimensional single crystal capable of guiding light waves through glass with little loss of light.
The color wheel indicates the angle of the fast or slow axis of birefringence. Image: Lehigh University) The article's lead author, Adam Stone, received his Ph d. in materials science and engineering from Lehigh in 2014.
The coauthors are Himanshu Jain, professor of materials science and engineering, and Volkmar Dierolf, professor of physics, both at Lehigh,
and researchers from Kyoto University in Japan and Polytechnique Montreal in Canada. The group says its achievement will boost ongoing efforts to develop photonic integrated circuits (PICS) that are smaller, cheaper, more energy-efficient and more reliable than current networks that use discrete optoelectronic components--waveguides, splitters, modulators, filters
, amplifiers--to transport optical signals.""A major trend in optics,"the researchers write, "has been a drive toward...
replacing systems of large discrete components that provide individual functions with compact and multifunctional PICS,
in much the same way that integration of electronics has driven the impressive advances of modern computer systems."
"To make this transition, however, improved methods of fabricating 3d PICS are needed, the researchers say."
"The methods currently employed for fabricating PICS are photolithographic and other processes suitable for planar geometries,
to prevent light from scattering as it is being transmitted and, second, to transmit and manipulate light signals fast enough to handle increasingly large quantities of data.
Glass, an amorphous material with an inherently disordered atomic structure, cannot meet these challenges, the researchers say.
Crystals, with their highly ordered specific lattice structure, have the requisite optical qualities.""Amorphous waveguides fundamentally lack second-order optical nonlinearity due to their isotropically disordered atomic structure,
"the researchers write, "so certain photonic applications that not only transport but also manipulate photonic signals...require crystalline substrates with second-order nonlinear optical response."
"The ability to pattern nonlinear optical crystals in glass is therefore essential for 3d laser-fabrication of PICS to achieve its full potential."
"To pattern crystals in glass, the Lehigh-led group employed femtosecond lasers, whose speed and precision make them useful for cataract and other eye surgeries.
A femtosecond is one-quadrillionth, or 10-15 of a second. Pulses emitted by femtosecond lasers last between a few femtoseconds and hundreds of femtoseconds.
Scientists have been attempting for years to make crystals in glass in order to prevent light from being scattered as light signals are transmitted,
The task is complicated by the"mutually exclusive"nature of the properties of crystal and glass. Glass turns to crystal when it is heated
says Jain, but it is critical to control the transition.""The question is, how long will this process take
and will we get one crystal or many. We want a single crystal; light cannot travel through multiple crystals.
And we need the crystal to be in the right shape and form.""After conducting experiments at Lehigh and at Kyoto University and Polytechnique Montreal,
the group built a single crystal in glass, demonstrated its waveguiding capabilities and quantified its transmission efficiency.
The glass and crystal both were composed of lanthanum borogermanate (Labgeo5), a ferroelectric material.""We achieved quality,
"says Dierolf,"by guiding light from one end of the crystal to the other with very little loss of light."
"We have made the equivalent of a wire to guide the light. With our crystal, it is possible to do this in 3d
so that the wire--the light--can curve and bend as it is transmitted. This gives us the potential of putting different components on different layers of glass."
"The fact that the demonstration was achieved using ferroelectric materials is another plus, says Dierolf.""Ferroelectric crystals have demonstrated an electrical-optical effect that can be exploited for switching
and for steering light from one place to another as a supermarket scanner does. Ferroelectric crystals can also transform light from one frequency to another.
This makes it possible to send light through different channels.""""Other groups have made crystal in glass
but were not able to demonstrate quality, "says Jain.""With the quality of our crystal, we have crossed the threshold for the idea to be useful.
As a result, we are now exploring the development of novel devices for optical communication in collaboration with a major company."
"The femtosecond laser provides several critical advantages, say Dierolf and Jain. The high intensity of the laser pulse enables nonlinear optical absorption.
or almost melt, until it is transformed into a crystal.""The unique focus of the femtosecond laser also makes it possible to"write"the crystal inside the glass and not on its surface."
Subsequently, NSF has provided funding for the work at Lehigh and, through Lehigh's International Materials Institute for New Functionalities in Glass, for the international collaborations as well.
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