Posts belonging to Category Materials



Nanotechnology Spacecraft

Renowned physicist Stephen Hawking is proposing a nanotechnology spacecraft that can travel at a fifth of the speed of light. At that speed, it could reach the nearest star in 20 years and send back images of a suspected “Second Earth” within 5 years. That means if we launched it today, we would have our first look at an Earth-like planet within 25 years.

Hawking proposed a nano-spacecraft, termed “Star Chip,” at the Starmus Festival IV: Life And The Universe, Trondheim, Norway, June 18 – 23, 2017. Hawking told attendees that every time intelligent life evolves it annihilates itself with “war, disease and weapons of mass destruction.” He asserted this as the primary reason why advanced civilizations from another part of the Universe are not contacting Earth and the primary reason we need to leave the Earth. His advocates we colonize a “Second Earth.”

Scientific evidence appears to support Hawking’s claim. The SETI Institute has been listening for evidence of extraterrestrial radio signals, a sign of advanced extraterrestrial life, since 1984. To date, their efforts have been futile. SETI claims, rightly, that the universe is vast, and they are listening to only small sectors, which is much like finding a needle in a haystack.

Source: http://www.huffingtonpost.com/

3-D Printed Graphene Foam

Nanotechnologists from Rice University and China’s Tianjin University have used 3-D laser printing to fabricate centimeter-sized objects of atomically thin graphene. The research could yield industrially useful quantities of bulk graphene and is described online in a new study in the American Chemical Society journal ACS Nano.

Laser sintering was used to 3-D print objects made of graphene foam, a 3-D version of atomically thin graphene. At left is a photo of a fingertip-sized cube of graphene foam; at right is a close-up of the material as seen with a scanning electron microscope

This study is a first of its kind,” said Rice chemist James Tour, co-corresponding author of the paper. “We have shown how to make 3-D graphene foams from nongraphene starting materials, and the method lends itself to being scaled to graphene foams for additive manufacturing applications with pore-size control.”

Graphene, one of the most intensely studied nanomaterials of the decade, is a two-dimensional sheet of pure carbon that is both ultrastrong and conductive. Scientists hope to use graphene for everything from nanoelectronics and aircraft de-icers to batteries and bone implants. But most industrial applications would require bulk quantities of graphene in a three-dimensional form, and scientists have struggled to find simple ways of creating bulk 3-D graphene.

For example, researchers in Tour’s lab began using lasers, powdered sugar and nickel to make 3-D graphene foam in late 2016. Earlier this year they showed that they could reinforce the foam with carbon nanotubes, which produced a material they dubbed “rebar graphene” that could retain its shape while supporting 3,000 times its own weight. But making rebar graphene was no simple task. It required a pre-fabricated 3-D mold, a 1,000-degree Celsius chemical vapor deposition (CVD) process and nearly three hours of heating and cooling.  “This simple and efficient method does away with the need for both cold-press molds and high-temperature CVD treatment,” said co-lead author Junwei Sha, a former student in Tour’s lab who is now a postdoctoral researcher at Tianjin. “We should also be able to use this process to produce specific types of graphene foam like 3-D printed rebar graphene as well as both nitrogen- and sulfur-doped graphene foam by changing the precursor powders.” Sha and colleagues conducted an exhaustive study to find the optimal amount of time and laser power to maximize graphene production. The foam created by the process is a low-density, 3-D form of graphene with large pores that account for more than 99 percent of its volume.

The 3-D graphene foams prepared by our method show promise for applications that require rapid prototyping and manufacturing of 3-D carbon materials, including energy storage, damping and sound absorption,” said co-lead author Yilun Li, a graduate student at Rice.

Source: http://news.rice.edu/

Artificial Intelligence At The Hospital

Diagnosing cancer is a slow and laborious process. Here researchers at University Hospital Zurich painstakingly make up biopsy slides – up to 50 for each patient – for the pathologist to examine for signs of prostate cancer. A pathologist takes around an hour and a half per patient – a task IBMs Watson supercomputer is now doing in fractions of a second.

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“If the pathologist becomes faster by using such a system I think it will pay off. Because my time is also worth something. If I sit here one and a half hours looking at slides, screening all these slides, instead of just signing out the two or three positive ones, and taking into account that there may be a .1 error rate, percent error rate. this will pay off, because I can do in one and a half hours at the end five patients,” says Dr. Peter Wild, University Hospital Zürich.

The hospital’s archive of biopsy images is being slowly fed into Watson – a process that will take years. But maybe one day pathologists won’t have to view slides through a microscope at all. Diagnosis is not the only area benefiting from AI. The technology is helping this University of Sheffield team design a new drug that could slow down the progress of motor neurone disease. A system built by British start-up BenevolentAI is identifying new areas for further exploration far faster than a person could ever hope to.

Benevolent basically uses their artificial intelligence system to scan the whole medical and biomedical literature. It’s not really easy for us to stay on top of millions of publications that come out every year. So they can interrogate that information, using artificial intelligence and come up with ideas for new drugs that might be used in a completely different disease, but may be applicable on motor neurone disease. So that’s the real benefit in their system, the kind of novel ideas that they come up with,” explains Dr. Richard Mead, Sitran, University of Sheffield. BenevolentAI has raised one hundred million dollars in investment to develop its AI system, and help revolutionise the pharmaceutical industry.

Source: http://www.reuters.com/

Nanoscale Memory Cell

Developing a superconducting computer that would perform computations at high speed without heat dissipation has been the goal of several research and development initiatives since the 1950s. Such a computer would require a fraction of the energy current supercomputers consume, and would be many times faster and more powerful. Despite promising advances in this direction over the last 65 years, substantial obstacles remain, including in developing miniaturized low-dissipation memory.

Researchers at the University of Illinois at Urbana-Champaign have developed a new nanoscale memory cell that holds tremendous promise for successful integration with superconducting processors. The new technology, created by Professor of Physics Alexey Bezryadin and graduate student Andrew Murphy, in collaboration with Dmitri Averin, a professor of theoretical physics at State University of New York at Stony Brook, provides stable memory at a smaller size than other proposed memory devices.

The device comprises two superconducting nanowires, attached to two unevenly spaced electrodes that were “written” using electron-beam lithography. The nanowires and electrodes form an asymmetric, closed superconducting loop, called a nanowire ‘SQUID’ (superconducting quantum interference device). The direction of current flowing through the loop, either clockwise or counterclockwise, equates to the “0” or “1” of binary code.

This is very exciting. Such superconducting memory cells can be scaled down in size to the range of few tens of nanometers, and are not subject to the same performance issues as other proposed solutions,” comments Bezryadin.

Murphy adds, “Other efforts to create a scaled-down superconducting memory cell weren’t able to reach the scale we have. A superconducting memory device needs to be cheaper to manufacture than standard memory now, and it needs to be dense, small, and fast.”

Source: https://physics.illinois.edu/

Nano-based Material Is 60 Times More Efficient To Produce Hydrogen

Global climate change and the energy crisis mean that alternatives to fossil fuels are urgently needed. Among the cleanest low-carbon fuels is hydrogen, which can react with oxygen to release energy, emitting nothing more harmful than water (H2O) as the product. However, most hydrogen on earth is already locked into H2O (or other molecules), and cannot be used for power.

Hydrogen can be generated by splitting H2O, but this uses more energy than the produced hydrogen can give back. Water splitting is often driven by solar power, so-called “solar-to-hydrogenconversion. Materials like titanium oxide, known as semiconductors with the wide band-gap, are traditionally used to convert sunlight to chemical energy for the photocatalytic reaction. However, these materials are inefficient because only the ultraviolet (UV) part of light is absorbed—the rest spectrum of sunlight is wasted.

Now, a team in Osaka University has developed a material to harvest a broader spectrum of sunlight. The three-part composites of this material maximize both absorbing light and its efficiency for water splitting. The core is a traditional semiconductor, lanthanum titanium oxide (LTO). The LTO surface is partly coated with tiny specks of gold, known as nanoparticles. Finally, the gold-covered LTO is mixed with ultrathin sheets of the element black phosphorus (BP), which acts as a light absorber.

BP is a wonderful material for solar applications, because we can tune the frequency of light just by varying its thickness, from ultrathin to bulk,” the team leader Tetsuro Majima says. “This allows our new material to absorb visible and even near infrared light, which we could never achieve with LTO alone.”

By absorbing this broad sweep of energy, BP is stimulated to release electrons, which are then conducted to the gold nanoparticles coating the LTO. Gold nanoparticles also absorb visible light, causing some of its own electrons to be jolted out. The free electrons in both BP and gold nanoparticles are then transferred into the LTO semiconductor, where they act as an electric current for water splitting.

Hydrogen production using this material is enhanced not only by the broader spectrum of light absorption, but by the more efficient electron conduction, caused by the unique interface between two dimensional materials of BP and LTO. As a result, the material is 60 times more active than pure LTO.

Source: http://resou.osaka-u.ac.jp/

30 Billion Switches Onto The New IBM Nano-based Chip

IBM is clearly not buying into the idea that Moore’s Law is dead after it unveiled a tiny new transistor that could revolutionise the design, and size, of future devices. Along with Samsung and Globalfoundries, the tech firm has created a ‘breakthrough’ semiconducting unit made using stacks of nanosheets. The companies say they intend to use the transistors on new five nanometer (nm) chips that feature 30 billion switches on an area the size of a fingernail. When fully developed, the new chip will help with artificial intelligence, the Internet of Things, and cloud computing.

For business and society to meet the demands of cognitive and cloud computing in the coming years, advancement in semiconductor technology is essential,” said Arvind Krishna, senior vice president, Hybrid Cloud, and director, IBM Research.

IBM has been developing nanometer sheets for the past 10 years and combined stacks of these tiny sheets using a process called Extreme Ultraviolet (EUV) lithography to build the structure of the transistor.

Using EUV lithography, the width of the nanosheets can be adjusted continuously, all within a single manufacturing process or chip design,” IBM and the other firms said. This allows the transistors to be adjusted for the specific circuits they are to be used in.

Source: http://www.wired.co.uk/

A Single Drop Of Blood To Test Agressive Prostate Cancer

A new diagnostic developed by Alberta scientists will allow men to bypass painful biopsies to test for aggressive prostate cancer. The test incorporates a unique nanotechnology platform to make the diagnostic using only a single drop of blood, and is significantly more accurate than current screening methods.

The Extracellular Vesicle Fingerprint Predictive Score (EV-FPS) test uses machine learning to combine information from millions of cancer cell nanoparticles in the blood to recognize the unique fingerprint of aggressive cancer. The diagnostic, developed by members of the Alberta Prostate Cancer Research Initiative (APCaRI), was evaluated in a group of 377 Albertan men who were referred to their urologist with suspected prostate cancer. It was found that EV-FPS correctly identified men with aggressive prostate cancer 40 percent more accurately than the most common test—Prostate-Specific Antigen (PSA) blood test—in wide use today.

Higher sensitivity means that our test will miss fewer aggressive cancers,” said John Lewis, the Alberta Cancer Foundation‘s Frank and Carla Sojonky Chair of Prostate Cancer Research at the University of Alberta. “For this kind of test you want the sensitivity to be as high as possible because you don’t want to miss a single cancer that should be treated.”

According to the team, current tests such as the PSA and digital rectal exam (DRE) often lead to unneeded biopsies. Lewis says more than 50 per cent of men who undergo biopsy do not have prostate cancer, yet suffer the pain and side effects of the procedure such as infection or sepsis. Less than 20 per cent of men who receive a are diagnosed with the aggressive form of prostate cancer that could most benefit from treatment.

It’s estimated that successful implementation of the EV-FPS test could eventually eliminate up to 600-thousand unnecessary biopsies, 24-thousand hospitalizations and up to 50 per cent of unnecessary treatments for prostate each year in North America alone. Beyond cost savings to the health care system, the researchers say the diagnostic test will have a dramatic impact on the health care experience and quality of life for men and their families.

Compared to elevated total PSA alone, the EV-FPS test can more accurately predict the result of prostate biopsy in previously unscreened men,” said Adrian Fairey, urologist at the Northern Alberta Urology Centre and member of APCaRI. “This information can be used by clinicians to determine which men should be advised to undergo immediate prostate biopsy and which men should be advised to defer and continue screening.”

Source:  https://medicalxpress.com/

Super Efficient Nanowires shape the future of electronics

A group of researchers at the Basque Excellence Research Center into Polymers (POLYMAT), the University of the Basque Country (UPV/EHU), the University of Barcelona, the Institute of Bioengineering of Barcelona (IBEC), and the University of Aveiro, and led by Aurelio Mateo-Alonso, the Ikerbasque research professor at POLYMAT, have developed a new suite of molecular wires or nanowires that are opening up new horizons in molecular electronics.

The growing demand for increasingly smaller electronic devices is prompting the need to produce circuits whose components are also as small as possible, and this is calling for fresh approaches in their design.

Molecular electronics has sparked great interest because the manufacture of electronic circuits using molecules would entail a reduction in their size. Nanowires are conducting wires on a molecular scale that carry the current inside these circuits. That is why the efficiency of these wires is crucially important.

In fact, one of the main novelties in this new suite of nanowires developed by the group led by Aurelio Mateo lies in their high efficiency, which constitutes a step forward in miniaturizing electronic circuits.
The findings have been published today in the journal Nature Communications.

Source: https://www.ehu.eus/

All Carbon Spin Transistor Is Quicker And Smaller

A researcher with the Erik Jonsson School of Engineering and Computer Science at UT Dallas has designed a novel computing system made solely from carbon that might one day replace the silicon transistors that power today’s electronic devices.

The concept brings together an assortment of existing nanoscale technologies and combines them in a new way,” said Dr. Joseph S. Friedman, assistant professor of electrical and computer engineering at UT Dallas who conducted much of the research while he was a doctoral student at Northwestern University.

The resulting all-carbon spin logic proposal, published by lead author Friedman and several collaborators in the June 5 edition of the online journal Nature Communications, is a computing system that Friedman believes could be made smaller than silicon transistors, with increased performance.

Today’s electronic devices are powered by transistors, which are tiny silicon structures that rely on negatively charged electrons moving through the silicon, forming an electric current. Transistors behave like switches, turning current on and off.

In addition to carrying a charge, electrons have another property called spin, which relates to their magnetic properties. In recent years, engineers have been investigating ways to exploit the spin characteristics of electrons to create a new class of transistors and devices called “spintronics.”

Friedman’s all-carbon, spintronic switch functions as a logic gate that relies on a basic tenet of electromagnetics: As an electric current moves through a wire, it creates a magnetic field that wraps around the wire. In addition, a magnetic field near a two-dimensional ribbon of carbon — called a graphene nanoribbon — affects the current flowing through the ribbon. In traditional, silicon-based computers, transistors cannot exploit this phenomenon. Instead, they are connected to one another by wires. The output from one transistor is connected by a wire to the input for the next transistor, and so on in a cascading fashion.

Source: http://www.utdallas.edu/

Scalable Catalyst Produces Cheap Pure Hydrogen

The “clean-energy economy” always seems a few steps away but never quite here. Fossil fuels still power transportation, heating and cooling, and manufacturing, but a team of scientists from Penn State and Florida State University have come one step closer to inexpensive, clean hydrogen fuel with a lower cost and industrially scalable catalyst that produces pure hydrogen through a low-energy water-splitting process.

Hydrogen fuel cells can boost a clean-energy economy not only in the transportation sector, where fast fueling and vehicle range outpace battery-powered vehicles, but also to store electrical energy produced by solar and wind. This research is another step forward to reaching that goal.
Energy is the most important issue of our time, and for energy, fuel cells are crucially important, and then for fuel cells, hydrogen is most important,” said Yu Lei, Penn State doctoral student and first author of an ACS Nano paper describing the water-splitting catalyst she and her colleagues theoretically predicted and then synthesized in the lab. “People have been searching for a good catalyst that can efficiently split water into hydrogen and oxygen. During this process, there will be no side products that are not environmentally friendly.”

The current industrial method of producing hydrogen — steam reforming of methane — results in the release of carbon dioxide into the atmosphere. Other methods use waste heat, from sources such as advanced nuclear power plants or concentrated solar power, both of which face technical challenges for commercial feasibility. Another industrial process uses platinum as the catalyst to drive the water-splitting process. Although platinum is a near-perfect catalyst, it is also expensive. A cheaper catalyst could make hydrogen a reasonable alternative to fossil fuels in transportation, and power fuel cells for energy storage applications.

Molybdenum disulfide has been predicted as a possible replacement for platinum, because the Gibbs free energy for hydrogen absorption is close to zero,” said Mauricio Terrones, professor of physics, materials science and engineering, and chemistry, Penn State. The lower the Gibbs free energy, the less external energy has to be applied to produce a chemical reaction.

Source: http://news.psu.edu/

Cellulose-based Ink For 3D Printing

Empa (Switzerland) researchers have succeeded in developing an environmentally friendly ink for 3D printing based on cellulose nanocrystals. This technology can be used to fabricate microstructures with outstanding mechanical properties, which have promising potential uses in implants and other biomedical applications.

Cellulose, along with lignin and hemicellulose, is one of the main constituents of wood. The biopolymer consists of glucose chains organized in long fibrous structures. In some places the cellulose fibrils exhibit a more ordered structure.

In order to produce 3D microstructured materials for composite applications, for instance, Empa researchers have been using a 3D printing method called “Direct Ink Writing” for the past year. During this process, a viscous substance – the printing ink – is squeezed out of the printing nozzles and deposited onto a surface, pretty much like a pasta machine. Empa researchers Gilberto Siqueira and Tanja Zimmermann from the Laboratory for Applied Wood Materials have now succeeded, together with Jennifer Lewis from Harvard University and André Studart from the ETH Zürich, in developing a new, environmentally friendly 3D printing ink made from cellulose nanocrystals (CNC).
The places with a higher degree of order appear in a more crystalline form. And it is these sections, which we can purify with acid, that we require for our research“, explains Siqueira. The final product is cellulose nanocrystals, tiny rod-like structures that are 120 nanometers long and have a diameter of 6.5 nanometers. And it is these nanocrystals that researchers wanted to use to create a new type of environmentally friendly 3D printing ink.They have now succeeded that  their new inks contain a full 20 percent CNC.

The biggest challenge was in attaining a viscous elastic consistency that could also be squeezed through the 3D printer nozzles“, says Siqueira. The ink must be “thick” enough so that the printed material stays “in shape” before drying or hardening, and doesn’t immediately melt out of shape again.

Source: https://www.empa.ch/

How Yo Make Sea Water Drinkable

Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies. Now the much sought-after development of making membranes capable of sieving common salts has been achieved. New research demonstrates the real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources. Graphene-oxide membranes developed at the National Graphene Institute have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Until now, however, they couldn’t be used for sieving common salts used in desalination technologies, which require even smaller sieves. Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.

The Manchester-based group have now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.

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Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology,” says Professor Rahul Raveendran Nair.

The new findings from a group of scientists at The University of Manchester have been published in the journal Nature Nanotechnology.

Source: http://www.manchester.ac.uk/
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