Refractive index changed from the outside In order to control the power of the light that exits the device,
A change in phase can result from a difference in the refractive index, which determines the speed of the waves.
whose refractive index can be changed from the outside, the relative phase of the two waves can be controlled
By applying a voltage the refractive index and hence the velocity of the plasmons in one arm of the interferometer can be varied,
whose refractive index changes when an electric voltage is applied and that thus modulates the plasmons inside the interferometer.
#Making polymer nanostructures from a greenhouse gas (Nanowerk News) A future where power plants feed their carbon dioxide directly into an adjacent production facility instead of spewing it up a chimney
it is also a good source of carbon for processes like polymer production. In the journal Angewandte Chemie("Construction of Versatile and Functional Nanostructures Derived from CO2-based Polycarbonates),
"American scientists have introduced now a two-step, one-pot conversion of CO2 and epoxides to polycarbonate block copolymers that contain both water-soluble and hydrophobic regions
and can aggregate into nanoparticles or micelles. Versatile nanostructures made from CO2 based polycarbonates. Wiley-VCH) CO2 and epoxides (highly reactive compounds with a three-membered ring made of two carbon atoms
and one oxygen atom) can be polymerized to form polycarbonates in reactions that use special catalysts.
These processes are a more environmentally friendly alternative to conventional production processes and have already been introduced by several companies.
However, because current CO2-based polycarbonates are hydrophobic and have no functional groups, their applications are limited.
In particular, biomedical applications, an area where the use of biocompatible polycarbonates is established well, have been left out.
the researchers have been able to produce amphiphilic polycarbonate block copolymers in which both the hydrophilic and hydrophobic regions are based on CO2.
They were also able to incorporate a variety of functional and charged groups into the polymers.
Because it is very difficult to find building blocks to make hydrophilic polycarbonates, the researchers used a trick:
and continue the polymerization. The AGE-containing polymer grows on both ends of the existing polycarbonate, leading to a triblock copolymer.
The length of the blocks can be controlled precisely. Subsequently a thiolene click reaction can be used to simply click a water-soluble group into place at the double bond.
Some of the amphiphilic polycarbonates made by this method are able to aggregate into particles or micelles in a self-organization process.
However, these devices, often created with nondegradable elastic polymers, bear an inherent risk of intestinal obstruction as a result of accidental fracture or migration.
Now, researchers at MITS Koch Institute for Integrative Cancer Research and Massachusetts General Hospital (MGH) have created a polymer gel that overcomes this safety concern
Image courtesy of the researchers) This polymer is ph-responsive: It is stable in the acidic stomach environment
and folding of devices into easily ingestible capsules meaning this polymer can be used to create safe devices designed for extremely prolonged residence in the stomach.
-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices")that describes the application of this new polymer gel for creating gastric devices.
the researchers were interested in developing a polymer with elastic properties. An elastic device can be folded into something small
But the size and shape of existing devices with elastic polymers have been limited by safety concerns,
Because of this, the researchers wanted their polymer to also be enteric or have a mechanism that would enable it to pass through the stomach unaltered before disintegrating in the intestines.
The proposed supramolecular polymer gel network. Structures in yellow are synthesized polymer; structures in purple are linear polymer;
and the red structures are inter-polymer hydrogen bonds. Image courtesy of the researchers) To lower any possible risk of obstruction,
we wanted a material that could dissolve in the intestines, thereby dissociating the device, and safely pass out of the body,
Zhang says. To create this new material, the researchers synthesized an elastic polymer and combined it in solution with a clinically utilized enteric polymer.
Adding hydrochloric acid and centrifuging the solution resulted in a flexible, yet resilient, polymer gel that exhibits both elastic and enteric properties.
The researchers used the gel polycaprolactone (PCL), a nontoxic, degradable polyester, to construct several device prototypes.
They first created ring-shaped devices by using the gel to link arcs of PCL in a circular mold.
These elastic devices had a diameter of 3 centimeters wider than the pylorus before they were folded into orally ingestible capsules.
the polymer gel dissolved, allowing for the safe passage of the small PCL pieces without obstruction.
Improving adherence The combined enteric and elastic properties of this polymer gel could significantly improve the design and adoption of gastric-resident devices.
With further work in adjusting the polymer composition or the design of the system they say that they could tailor devices to release drugs over a specific timeframe of up to weeks or months at a time.
Ribo-T may be able to be tuned to produce unique and functional polymers for exploring ribosome functions
or producing designer therapeutics and perhaps one day even non-biological polymers. No one has developed ever something of this nature. e felt like there was a small very small chance Ribo-T could work,
Researchers at Purdue University have shown how an optical material made of aluminum-doped zinc oxide (AZO) is able to modulate
"meaning the refractive index is near zero, a quality found normally in metals and new"metamaterials,
"which contain features, patterns or elements that enable unprecedented control of light by harnessing clouds of electrons called surface plasmons.
"If you are operating in the range where your refractive index is low then you can have enhanced an effect,
The researchers"doped"zinc oxide with aluminum, meaning the zinc oxide is impregnated with aluminum atoms to alter the material's optical properties.
Doping the zinc oxide causes it to behave like a metal at certain wavelengths and like a dielectric at other wavelengths.
They found that it changes its optical properties such as transparency, reflectivity and absorptivity instantaneously, while the structure exhibits only a delayed reaction to the excitation.
which is decisive for the optical properties such as transmission, reflectivity and absorptivity. Crystalline and transparent:
If it were possible to extract the energy of the infrared laser pulse before the crystal has melted
which race through a crystal differently than through irregularly structured materials. Since the researchers also sent the electrons after the exciting laser pulse with a different delay
The crystal loses its regular structure in the process. Although five picoseconds sounds short, this time is sufficient to qualify the material for uses other than data storage.
and aligned than carbon nanotubes, another material under investigation for membrane separation. Kumar and co-authors report their development in a recent issue of the Proceedings of the National Academy of Science("Highly permeable artificial water channels that can self-assemble into two-dimensional arrays"."
#New insight on how crystals form may advance materials, health and basic science research Scientists have worked long to understand how crystals grow into complex shapes.
Crystals are important in materials from skeletons and shells to soils and semiconductor materials, but much is unknown about how they form.
Now, an international group of researchers has shown how nature uses a variety of pathways to grow crystals that go beyond the classical, one-atom-at-a-time route.
The findings, published today in Science("Crystallization by particle attachment in synthetic, biogenic, and geologic environments"),have implications for decades-old questions in science
and technology such as how animals and plants grow minerals into shapes that have no relation to their original crystal symmetry.
and laboratory-grown crystals that cannot be explained by traditional theories, "said Patricia Dove, a University Distinguished Professor at Virginia Tech and the C. P. Miles Professor of Science in the College of Science."
"We show how these crystals can be built up into complex structures by attaching particles as nanocrystals, clusters,
and pathways to becoming a crystal our challenge was to put together a framework to understand them."
and the earth and materials sciences, including at the Department of energy's Pacific Northwest National Laboratory. At home, these researchers conduct lab experiments, investigate animal skeletons,
and begin to combine with each other and with nearby crystals and other surfaces. For example, nanocrystals prefer to become oriented along the same direction as the larger crystal before attaching,
much like adding Legos. In contrast, amorphous conglomerates can simply aggregate. These atoms later become organized by"doing the wave"through the mass to rearrange into a single crystal,
researchers said. Study authors say much work needs to be done to understand the forces that cause these particles to move and combine.
what appear to be crystals with the traditional faceted surfaces or they can have unexpected completely shapes
"Our group synthesized the evidence to show these pathways to growing a crystal become possible because of interplays between of thermodynamic and kinetic factors."
"By understanding how animals form crystals into the working structures known as shells, teeth, and bones, scientists will have a bigger toolbox for interpreting the crystals formed in nature.
The insights may also help in the design of novel materials and explain unusual mineral patterns in rocks.
Thats what Northeastern physicists Swastik Kar and Srinivas Sridhar found during their four-year project to modify graphene, a stronger-than-steel infinitesimally thin lattice of tightly packed carbon atoms.
The pair was controlled familiar with alloys combinations of elements that resulted in materials with properties that surpassed graphenesfor example,
Just as with nappies, adding water causes the acrylate polymer to swell. After stretching the fluorescent-tagged molecules move further away from each other;
which resides at the boundary between the neural retina and the retinal pigment epithelium. Their stepwise nduction-reversalculture method induces the formation of boundary tissue,
This degree of cellular organization is the closest scientists have yet come to building self-growing retinal tissue from stem cells. ur results are consistent with the current view that the retinal pigment epithelium
and FGFR induced the transition from NR tissue to retinal pigment epithelium (RPE), and that removing this inhibition facilitated the reversion of this RPE-like tissue back to the NR fate.
like a polymer, and could literally be sucked into a glass needle or pipette. From there, we simply asked,
or flexible polymers they cause inflammation in the tissue that requires periodically changing the position or the stimulation. ut with our injectable electronics, it as if it not there at all.
researchers lay out a mesh of nanowires sandwiched in layers of organic polymer. The first layer is dissolved then, leaving the flexible mesh,
which it can then relay to human cells. ur artificial neuron is made of conductive polymers
or is shot down there is no terrible news to pass to the families of the aircrew just a pile of crumpled metal.
but the top brass will recommend an ordinary (low risk) Foreign Military Sales (FMS) buy that will also exclude Australian industry from the system global supply chain.
because chromatophores sacs of pigment in the skin are stretched by the surrounding muscle, expanding the sacs to create large brown patches.
Using X-ray crystallography they found that the bases could incorporate themselves into strands of both natural and unnatural bases that included runs of Z and P up to six bases long.
but is absorbed by hemozoin waste crystals that are produced by the malaria parasite Plasmodium falciparum when it feeds on blood.
When the crystals absorb this energy, they warm the surrounding blood plasma, making it bubble. An oscilloscope placed on the skin alongside the laser senses these nanoscale bubbles
Normally the layer of water next to any solid object has high surface tension making it viscous."
They also scattered polystyrene beads 10 micrometres wide into a Petri dish filled with macrophages a type of white blood cell that ingests foreign material.
the permeability of the blood-brain barrier was more than 50 percent higher in people with mild cognitive impairment.
In the standard configuration the optical sensors are packaged in a hermetically-sealed stainless steel tube with an outer diameter of 800 m. This configuration provides a thermal constant as low as 70 ms and long term stability up to 600°C (1,
this project will utilize 3ds's Direct Metal Printing technology as well as the additive manufacturing and materials expertise of Penn State's Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3d).
and Direct Metal 3d printing capabilities to meet the high standards of production demanded by the US Air force.
aerospace and defense manufacturers are expected to gain full control of the direct metal manufacturing process at the layer level,
delivering"fully dense, chemically-pure, flightworthy metals parts
#Precision optics deliver next-gen endoscopes A trio of companies has collaborated to develop a tiny new CMOS imaging module designed specifically for endoscopes.
which interact with each other within the silica fiber optic cables. The researchers note that this approach could be used in systems with far more communication channels.
2015 A new breed of quantum dots (QDS) could enable multilayer solar cells that capture more of the sun energy.
Individual germanium quantum dots were coated with silicon dioxide (silica), doped to make them p-type, and then deposited, using Natcore's liquid phase deposition (LPD) process,
or germanium quantum dots into layers using a process such as Natcore, which appears to be ideal for mass production,
which quantum dots are used to form both the p-type and n-type materials. Once this next step is achieved
#Ultrafast Lasers Create 3-D Crystal Waveguides in Glass Ultrafast Lasers Create 3-D Crystal Waveguides in Glassbethlehem, Pa.
June 9, 2015 Femtosecond laser pulses can create complex single-crystal waveguides inside glass a discovery that could enable photonic integrated circuits (PICS) that are smaller, cheaper, more energy-efficient and more reliable than current networks that use
"Other groups have made crystal in glass but were not able to demonstrate quality, "said professor Himanshu Jain."
"With the quality of our crystal, we have crossed the threshold for the idea to be useful.
The color wheel indicates the angle of the fast or slow axis of birefringence. Courtesy of Lehigh University.
Dynamic phase modulation allows growth of symmetric crystal junctions with single-pass writing, the researchers said."
"With our crystal, it is possible to do this in 3-D so that the wire the light can curve
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.
but crystals, with their highly ordered lattice structure, have the requisite optical qualities. Scientists have been attempting for years to make crystals in glass in order to prevent light signals from being scattered
Jain said. The task is complicated by the"mutually exclusive"nature of the properties of crystal and glass.
Glass turns to crystal when it is heated, he said, 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,
"Jain said.""We want a single crystal; light cannot travel through multiple crystals. And we need the crystal to be in the right shape and form."
"The fact that the demonstration was achieved using Labgeo5, a ferroelectric material, creates additional possibilities, Dierolf said."
"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 said,
"he.""Ferroelectric crystals can also transform light from one frequency to another. This makes it possible to send light through different channels."
"The research was published in Scientific Reports (doi: 10.1038/srep10391. For more information, visit www1. lehigh. edu. Harsh Environments No Match for New Fiber Sensor Nanofiber Fabrication Boosts Quantum computing Sulfur Copolymers Boost IR Optics
Bandwidth Demands Drive Fiber optics Advance s
#Graphene Filaments Provide Tunable On-Chip Light source Graphene Filaments Provide Tunable On-Chip Light Sourcenew YORK, June 15,
2015 Incandescent bulbs may be a thing of the past, but the principle of light-emitting filaments may have a new use in displays and optical communications.
the Indigo-Clean fixtures emit high-intensity narrow-spectrum (HINS) visible light at 405 nm, which produces a chemical reaction that kills bacteria from the inside,
Continuous indigo light, on the other hand, is lethal to pathogens but safe for use in the presence of patients and staff.
visit www. indigo-clean. com and www. strath. ac. uk. Biophotonics Market Poised for Growth Top Biophotonics Stories of 2014 Ophthalmology Devices Market Set to
"To study this, the researchers developed ultrafast electron crystallography (UEC), which allowed them to observe directly the transitioning atomic configuration of a prototypical phase-change material, germanium telluride (Gete), under femtosecond laser pulses.
The sensor uses a nanoengineered silica chip with an active layer of ions that fluoresce
The bottom right panel is a composite of all wavelength channels. Based on single-lens designs, today's multispectral microscopes survey a single point at a time,
When crystalline materials such as quartz and ceramics are stretched or compressed, they generate an electric charge. That's called piezoelectricity,
and prevents the water from doing more damage (such as rusting the steel bars that are present in a lot of concrete structures).
and Aix-Marseille Universite have built binary data into a strand of synthetic polymer, a minuscule chain of chemical information about 60,000 times thinner than a strand of hair.
Right now, storing one zettabyte (1 billion terabytes) takes roughly 1000 kilograms of cobalt alloy
A zettabyte of Lutz's synthesized polymer would be about 10 grams. The process of building a polymer is like stringing a pearl necklace.
As its simplest level, digital information is coded into zeros and ones. Researchers assigned certain chemical components called monomers to represent zero and one.
To build the polymer, it just a matter of chemically stringing those monomers together in a specific order,
creating a polymer. Scientists use a mass spectrometer, a device often used to sequence DNA, to read the data later.
The technology is still in its infancy. Lutz says that research has been underway for about two years
and right now researchers can chain just a handful of bytes of information together. But Lutz has high hopes that they will be able to process kilobytes of information in the next five years.
He looks to the recent advances in coding biological strands of DNA in a similar manner as a roadmap for how synthetic polymer technology can progress.
Lutz, working on synthetic polymers, says that his process, while years away from being viable, is suited actually better for the task of storing data than DNA is.
The resulting objects are an environmentally friendly and sustainable alternative to the metals and plastics that currently dominate 3d printing.
The researchers presented their work this week at a conference titled ew Materials From Trees.
The researchers were also able to insert carbon nanotubes into the dry object so that it could conduct electricity.
cellulose is a very abundant polymer. 3d printed objects made of cellulose would biodegradable and could even capture carbon dioxide that would
which uses carbon fibre composites could benefit, Duncan wass told Forbes. t the consumer end of the market that could be sports equipment, bike frames,
and sandwiching it between layers of plastic, the researchers were able to create an ultra-thin and more efficient display.
Now researchers have figured out how to fix mycosporines in place by putting them around a polymer scaffoldingor this experiment, they used chitosan,
but plenty of other polymers would work just as well, they note. The material could absorb UV-B rays 192 percent more effectively than most commercial sunscreens,
The research used zinc oxide (an inorganic compound found in most sunscreens as a fine powder mixed into a lotion) as the UV sensing material,
This thin zinc oxide layer is engineered with a platelike structure that we call micro-tectonics, these plates can slide across each other bit like geological plates that form the earth crust allowing for high sensitivity
The glasses are made from impact-resistant polycarbonate with a scratch-resistant lens that also reduces glare to the eyes.
Two different metals, a anode and a cathode are submerged into different solutions and are connected by a salt bridge to form a reaction,
A polyurethane sheet divides the umbrella from its case and pushes droplets toward the tank,
#Scientists Create Liquid Metal Antenna By placing an electrical potential across the interface between liquid eutectic gallium and indium and an electrolyte,
Dr Adams and his colleagues found that they could cause the metals to spread by applying a positive voltage
or to contract by applying a negative voltage. sing a liquid metal that can change its shape allows us to modify antenna properties more dramatically than is possible with a fixed conductor,
and elongate a filament of liquid metal and change the antenna operating frequency. Applying a small positive voltage causes the metal to flow into a capillary,
while applying a small negative voltage makes the metal withdraw from the capillary. he positive voltage electrochemically deposits an oxide on the surface of the metal that lowers the surface tension,
while a negative potential removes the oxide to increase the surface tension. These differences in surface tension dictate which direction the metal will flow,
Dr Adams explained. his advance makes it possible to remove or regenerate enough of the xide skinwith an applied voltage to make the liquid metal flow into or out of the capillary.
We call this lectrochemically controlled capillarity, which is much like an electrochemical pump for the liquid metal.
Although antenna properties can be reconfigured to some extent by using solid conductors with electronic switches
the liquid metal approach greatly increases the range over which the antenna operating frequency can be tuned. or eutectic gallium-indium monopoles with lengths between 75m and 4m, the measured resonance frequency tunes from 0. 66 GHZ to 3. 4hz for a tuning
ratio to 5. 2: 1, which is beyond the ratio obtained by switch or varactor-based antennas. urthermore, the measured total efficiency ranges from 41%to 70,
%which, while lower than a conventional monopole, presents a tradeoff between efficiency and versatility that is evident in most tunable systems. ur antenna prototype using liquid metal can tune over a range of at least two times greater than systems using electronic switches,
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.
the scientists found that the maximum force of the water striderslegs is always just below the maximum force that water surface tension can withstand.
and gradually increases but that never exceeds the surface tension force of water. As well, the high-speed cameras reveal that the water strider sweeps its legs inward
To reproduce this feat in a surface tension-dominant jumping robot, we elucidated the hydrodynamics involved
and also allows for the coating of larger plastic carrier surfaces, Wöll says. Thanks to their mechanical properties
More specifically, Lexus'use of liquid nitrogenhich has a temperature of-321 degrees Fahrenheitells us that they're using a high-temperature superconductor like yttrium barium copper oxide,
and Steven P. Levitan, Ph d.,John A. Jurenko professor of electrical and computer engineering, integrated models for self-oscillating polymer gels and piezoelectric micro-electric-mechanical systems to devise a new
The researchers have also been working with orphees flexible mobile devices with lycra or alloy displays
And Doesn't Metals, which conduct electricity, and insulators, which don, are polar opposites. At least that what wee believed until now.
On the other hand, electrons in conducting materials such as metals flow freely over long distances. So how can you possibly get electrons behaving in both ways in a single material?
which the bulk itself behaves both as a metal and an insulator. Crystal clear? The material we explored is a well-known insulator that has been studied
and magnetisation a property known as uantum oscillations Such quantum oscillations are inherently a property of metals,
it was also severely violating the rules for conventional metals. Explaining the inexplicable How can we resolve the apparent contradiction inherent in a material that is both a metal and an insulator?
One possibility is that, contrary to current understanding, electrons in certain insulators can somehow behave as if they were in a metal.
This behaviour may involve the strange properties of quantum mechanics. According to quantum mechanics, particles can occupy two states at the same time.
In this way, the strange behaviour of our material could be explained by the fact that wee discovered a new quantum state that fluctuates between being a metal and an insulator.
Our discovery of a material that is neither a conventional metal nor a conventional insulator could be such an mergentquantum phase of matter.
we plan to do more experiments on high-quality crystals to distinguish between predictions of the various theories.
decades of conventional wisdom regarding the fundamental dichotomy between metals and insulators are likely about to be turned on their head.
and used to produce various types of fuels, plastics and elastomers. In this case, the team at Global Bioenergies refined it into a clear, high-grade,'unleadedfuel."
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