Posts belonging to Category molecular electronics



Ultra-fast Data Processing At Nanoscale

Advancement in nanoelectronics, which is the use of nanotechnology in electronic components, has been fueled by the ever-increasing need to shrink the size of electronic devices like nanocomputers in a bid to produce smaller, faster and smarter gadgets such as computers, memory storage devices, displays and medical diagnostic tools.

While most advanced electronic devices are powered by photonics – which involves the use of photons to transmit informationphotonic elements are usually large in size and this greatly limits their use in many advanced nanoelectronics systems. Plasmons, which are waves of electrons that move along the surface of a metal after it is struck by photons, holds great promise for disruptive technologies in nanoelectronics. They are comparable to photons in terms of speed (they also travel with the speed of light), and they are much smaller. This unique property of plasmons makes them ideal for integration with nanoelectronics. However, earlier attempts to harness plasmons as information carriers had little success.

Addressing this technological gap, a research team from the National University of Singapore (NUS) has recently invented a novel “converter” that can harness the speed and small size of plasmons for high frequency data processing and transmission in nanoelectronics.

This innovative transducer can directly convert electrical signals into plasmonic signals, and vice versa, in a single step. By bridging plasmonics and nanoscale electronics, we can potentially make chips run faster and reduce power losses. Our plasmonic-electronic transducer is about 10,000 times smaller than optical elements. We believe it can be readily integrated into existing technologies and can potentially be used in a wide range of applications in the future,” explained Associate Professor Christian Nijhuis from the Department of Chemistry at the NUS Faculty of Science, who is the leader of the research team behind this breakthrough.

This novel discovery was first reported in the journal Nature Photonics.

Source: http://news.nus.edu.sg/

How To Extract Hydrogen Fuel from Seawater

It’s possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF researcher Yang Yang from the University of Central Florida (UCF)  has come up with a new hybrid nanomaterial that harnesses solar energy and uses it to generate hydrogen from seawater more cheaply and efficiently than current materials. The breakthrough could someday lead to a new source of the clean-burning fuel, ease demand for fossil fuels and boost the economy of Florida, where sunshine and seawater are abundant. Yang, an assistant professor with joint appointments in the University of Central Florida’s NanoScience Technology Center and the Department of Materials Science and Engineering, has been working on solar hydrogen splitting for nearly 10 years.

It’s done using a photocatalyst – a material that spurs a chemical reaction using energy from light. When he began his research, Yang focused on using solar energy to extract hydrogen from purified water. It’s a much more difficulty task with seawater; the photocatalysts needed aren’t durable enough to handle its biomass and corrosive salt.

We’ve opened a new window to splitting real water, not just purified water in a lab,” Yang said. “This really works well in seawater.”

As reported in the journal Energy & Environmental Science, Yang and his research team have developed a new catalyst that’s able to not only harvest a much broader spectrum of light than other materials, but also stand up to the harsh conditions found in seawater.

 

Source: https://today.ucf.edu/

Paper Supercapacitor

By coating ordinary paper with layers of gold nanoparticles and other materials, researchers have fabricated flexible paper supercapacitors that exhibit the best performance of any textile-type supercapacitor to date. In particular, the paper supercapacitors address one of the biggest challenges in this area, which is to achieve a high energy density in addition to an already high power density, since both properties are essential for realizing high-performance energy-storage devices. In the future, flexible paper supercapacitors could be used in wearable electronics for biomedical, consumer, and military applications. The researchers, led by Seung Woo Lee at the Georgia Institute of Technology and Jinhan Cho at Korea University, have published a paper on the flexible paper supercapacitor electrodes in a recent issue of Nature Communications. As energy-storage devices, supercapacitors have several advantages over batteries, such as a higher power density, rapid charge/discharge rate, and longer lifetime, yet they lag behind batteries in energy density (the amount of energy that can be stored in a given amount of space). Although several methods have been attempted to improve the energy density of paper supercapacitors by coating them with various conductive materials, often these methods have the drawback of reducing the power density.

The paper electrodes based on layer-by-layer-assembled metal nanoparticles exhibit metal-like electric conductivity, paper-like mechanical properties, and a large surface area without any thermal treatment and/or mechanical pressing,” explains coauthor Yongmin Ko at Korea University. “The periodic insertion of metal nanoparticles within high-energy nanoparticle-based paper electrodes could resolve the critical tradeoff in which an increase in the loading amount of materials to enhance the energy density of supercapacitors decreases the power density.”
Tests  showed that the flexible paper supercapacitors had a maximum capacitance that is higher than any previously reported textile-based supercapacitor. In addition, the new devices exhibits an excellent capacity retention, demonstrated by a 90% capacity retention after 5,000 bending cycles.

Source: http://me.gatech.edu/

How To Forge Graphene In 3D Shape

The wonder material graphene gets many of its handy quirks from the fact that it exists in two dimensions, as a sheet of carbon only one atom thick. But to actually make use of it in practical applications, it usually needs to be converted into a 3D form. Now, researchers have developed a new and relatively simple way to do just that, using lasers to “forge” a three-dimensional pyramid out of graphene.

This isn’t the first time graphene has been given an extra dimension. In 2015, researchers from the University of Illinois molded graphene into 3D structures by layering it onto shaped substrates, and early this year MIT scientists found that tubes of the stuff could be shaped into 3D coral-like structures 10 times stronger than steel but just five percent as dense. Rice University researchers have also recently made graphene foam and reinforced it with carbon nanotubes.

But this new technique, developed by researchers in Finland and Taiwan, might be an easier and faster method to make 3D graphene. By focusing a laser onto a fine point on a 2D graphene lattice, the graphene at that spot is irradiated and bulges outwards. A variety of three-dimensional shapes can be made by writing patterns with the laser spot, with the height of the shape controlled by adjusting the irradiation dose at each particular point.

The team illustrated that technique by deforming a sheet of graphene into a 3D pyramid, standing 60 nm high. That sounds pretty tiny, but it’s 200 times taller than the graphene sheet itself.

We call this technique optical forging, since the process resembles forging metals into 3D shapes with a hammer,” says Mika Pettersson, co-author of the study. “In our case, a laser beam is the hammer that forges graphene into 3D shapes. The beauty of the technique is that it’s fast and easy to use; it doesn’t require any additional chemicals or processing. Despite the simplicity of the technique, we were very surprised initially when we observed that the laser beam induced such substantial changes on graphene. It took a while to understand what was happening.”

The researchers initially assumed that the laser had “doped” the graphene, introducing impurities into the material, but after further examination they found that wasn’t the case.

When we first examined the irradiated graphene, we were expecting to find traces of chemical species incorporated into the graphene, but we couldn’t find any,” comments Wei Yen Woon, co-author of the study. “After some more careful inspections, we concluded that it must be purely structural defects, rather than chemical doping, that are responsible for such dramatic changes on graphene.

The scientists explain that the optically forged graphene is structurally sound, highlighting its potential for building 3D architectures out of the material for a wide range of applications. In this form, the graphene has different electronic and optical properties from its 2D counterpart.

The research was published in the journal Nano Letters.

Source: Academy of Finland

The Ultra Smart Community Of The Future

Japan’s largest electronics show CEATEC – showcasing its version of our future – in a connected world with intelligent robots And cars that know when the driver is falling asleep. This is Omron‘s “Onboard Driving Monitoring Sensor,” checking its driver isn’t distracted.

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We are developing sensors that help the car judge what state the driver is in, with regards to driving. For example, if the driver has his eyes open and set on things he should be looking at, if the driver is distracted or looking at smartphones, and these types of situations,” explains Masaki Suwa, Omron Corp. Chief Technologist.

After 18 years of consumer electronics, CEATEC is changing focus to the Internet of Things and what it calls ‘the ultra-smart community of the future‘ A future where machines take on more important roles – machines like Panasonic‘s CaloRieco – pop in your plate and know exactly what you are about to consume.

By placing freshly cooked food inside the machine, you can measure total calories and the three main nutrients: protein, fat and carbohydrate. By using this machine, you can easily manage your diet,” says Panasonic staff engineer Ryota Sato.

Even playtime will see machines more involved – like Forpheus the ping playing robot – here taking on a Olympic bronze medalist – and learning with every stroke.
Rio Olympics Table Tennis player , Jun Mizutani, Bronze Medalist, reports: “It wasn’t any different from playing with a human being. The robot kept improving and getting better as we played, and to be honest, I wanted to play with it when it had reached its maximum level, to see how good it is.”

Graphene, Not Glass, Is The Key To Better Optics

A lens just a billionth of a metre thick could transform phone cameras. Researchers at Swinburne University in Melbourne, Australia, have created ultra-thin lenses that cap an optical fibre, and can produce images with the quality and sharpness of much larger glass lenses.

Compared with current lenses, our graphene lens only needs one film to achieve the same resolution,” says Professor Baohua Jia, a research leader at Swinburne’s Centre for Micro-Photonics. “In the future, mobile phones could be much thinner, without having to sacrifice the quality of their cameras. Our lens also allows infrared light to pass through, which glass lenses don’t.”

Producing graphene can be costly and challenging, so Baohua and her colleagues used a laser to pattern layers of graphene oxide (graphene combined with oxygen). By then removing the oxygen, they produced low-cost, patterned films of graphene, a thousand times thinner than a human hair. “By patterning the graphene oxide film in this way, its optical and electrical properties can be altered, which allowed us to place them in different devices,” she says.

Warm objects give off infrared light, so mobile phones with graphene lenses could be used to scan for hotspots in the human body and help in the early identification of diseases like breast cancer. By attaching the lens to a fibre optic tip, endoscopes — instruments that are currently several millimetres wide—could be made a million times smaller. The team is also investigating graphene’s amazing properties for their potential use as supercapacitors, capable of storing very large amounts of energy, which could replace conventional batteries.

Baohua’s work on graphene lenses was published in Nature Communications.

Source: https://cosmosmagazine.com/

Renewable Fuel From Water

Physicists at Lancaster University (in UK) are developing methods of creating renewable fuel from water using quantum technologyRenewable hydrogen can already be produced by photoelectrolysis where solar power is used to split water molecules into oxygen and hydrogen. But, despite significant research effort over the past four decades, fundamental problems remain before this can be adopted commercially due to inefficiency and lack of cost-effectivenessDr Manus Hayne  from the Department of Physics said: “For research to progress, innovation in both materials development and device design is clearly needed.

The Lancaster study, which formed part of the PhD research of Dr Sam Harrison, and is published in Scientific Reports, provides the basis for further experimental work into the solar production of hydrogen as a renewable fuel. It demonstrates that the novel use of nanostructures could increase the maximum photovoltage generated in a photoelectrochemical cell, increasing the productivity of splitting water molecules.

To the authors’ best knowledge, this system has never been investigated either theoretically or experimentally, and there is huge scope for further work to expand upon the results presented here,” said Dr Haynes. “Fossil-fuel combustion releases carbon dioxide into the atmosphere, causing global climate change, and there is only a finite amount of them available for extraction. We clearly need to transition to a renewable and low-greenhouse-gas energy infrastructure, and renewable hydrogen is expected to play an important role.

Fossil fuels accounted for almost 90% of energy consumption in 2015, with absolute demand still increasing due to a growing global population and increasing industrialisationPhotovoltaic solar cells are currently used to convert sunlight directly into electricity but solar hydrogen has the advantage that it is easily stored, so it can be used as and when needed. Hydrogen is also very flexible, making it highly advantageous  for remote communities. It can be converted to electricity in a fuel cell, or burnt in a boiler or cooker just like natural gas. It can even be used to fuel aircraft.

Source: http://www.lancaster.ac.uk/

Nano Robots Build Molecules

Scientists at The University of Manchester have created the world’s first ‘molecular robot’ that is capable of performing basic tasks including building other molecules.

The tiny robots, which are a millionth of a millimetre in size, can be programmed to move and build molecular cargo, using a tiny robotic arm.

Each individual robot is capable of manipulating a single molecule and is made up of just 150 carbon, hydrogen, oxygen and nitrogen atoms. To put that size into context, a billion billion of these robots piled on top of each other would still only be the same size as a single grain of salt. The robots operate by carrying out chemical reactions in special solutions which can then be controlled and programmed by scientists to perform the basic tasks.

In the future such robots could be used for medical purposes, advanced manufacturing processes and even building molecular factories and assembly lines.

All matter is made up of atoms and these are the basic building blocks that form molecules. Our robot is literally a molecular robot constructed of atoms just like you can build a very simple robot out of Lego bricks, explains Professor David Leigh, who led the research at University’s School of Chemistry. “The robot then responds to a series of simple commands that are programmed with chemical inputs by a scientistIt is similar to the way robots are used on a car assembly line. Those robots pick up a panel and position it so that it can be riveted in the correct way to build the bodywork of a car. So, just like the robot in the factory, our molecular version can be programmed to position and rivet components in different ways to build different products, just on a much smaller scale at a molecular level.”

The research has been published in Nature.

Source: http://www.manchester.ac.uk/

Optical Computer

Researchers at the University of Sydney (Australia) have dramatically slowed digital information carried as light waves by transferring the data into sound waves in an integrated circuit, or microchipTransferring information from the optical to acoustic domain and back again inside a chip is critical for the development of photonic integrated circuits: microchips that use light instead of electrons to manage data.

These chips are being developed for use in telecommunications, optical fibre networks and cloud computing data centers where traditional electronic devices are susceptible to electromagnetic interference, produce too much heat or use too much energy.

The information in our chip in acoustic form travels at a velocity five orders of magnitude slower than in the optical domain,” said Dr Birgit Stiller, research fellow at the University of Sydney and supervisor of the project.

It is like the difference between thunder and lightning,” she said.

This delay allows for the data to be briefly stored and managed inside the chip for processing, retrieval and further transmission as light wavesLight is an excellent carrier of information and is useful for taking data over long distances between continents through fibre-optic cables.

But this speed advantage can become a nuisance when information is being processed in computers and telecommunication systems.

Source: https://sydney.universty.au/

Very Fast Magnetic Data Storage

For almost seventy years now, magnetic tapes and hard disks have been used for data storage in computers. In spite of many new technologies that have been developed in the meantime, the controlled magnetization of a data storage medium remains the first choice for archiving information because of its longevity and low price. As a means of realizing random access memories (RAMs), however, which are used as the main memory for processing data in computers, magnetic storage technologies were long considered inadequate. That is mainly due to its low writing speed and relatively high energy consumption.

In 1956, IBM introduced the first magnetic hard disc, the RAMAC. ETH researchers have now tested a novel magnetic writing technology that could soon be used in the main memories of modern computers

Pietro Gambardella, Professor at the Department of Materials of the Eidgenössische Technische Hochschule Zürich (ETHZ, Switzerland), and his colleagues, together with colleagues at the Physics Department and at the Paul Scherrer Institute (PSI), have now shown that using a novel technique, magnetic storage can still be achieved very fast and without wasting energy.

In 2011, Gambardella and his colleagues already demonstrated a technique that could do just that: An electric current passing through a specially coated semiconductor film inverted the magnetization in a tiny metal dot. This is made possible by a physical effect called spin-orbit-torque. In this effect, a current flowing in a conductor leads to an accumulation of electrons with opposite magnetic moment (spins) at the edges of the conductor. The electron spins, in turn, create a magnetic field that causes the atoms in a nearby magnetic material to change the orientation of their magnetic moments. In a new study the scientists have now investigated how this process works in detail and how fast it is.

The results were recently published in the scientific journal Nature Nanotechnology.

Source: https://www.ethz.ch/

Magnetic Cellular ‘Legos’ For Tissue Engineering

By incorporating magnetic nanoparticles in cells and developing a system using miniaturized magnets, researchers from 3 associated universities* in Paris (France) , have succeeded in creating cellular magneticLegos.” They were able to aggregate cells using only magnets and without an external supporting matrix, with the cells then forming a tissue that can be deformed at will. This approach, which is detailed in Nature Communications, could prove to be a powerful tool for biophysical studies, as well as the regenerative medicine of tomorrow.

Nanotechnology has quickly swept across the medical field by proposing sometimes unprecedented solutions at the furthest limits of current treatments, thereby becoming central to diagnosis and therapy, notably for the regeneration of tissue. A current challenge for regenerative medicine is to create a cohesive and organized cellular assembly without using an external supporting matrix. This is a particularly substantial challenge when it involves synthesizing thick and/or large-sized tissue, or when these tissues must be stimulated like their in vivo counterparts (such as cardiac tissue or cartilage) in order to improve their functionality.

The researchers met this challenge by using magnetism to act on the cells at a distance, in order to assemble, organize, and stimulate them. Cells, which are the building blocks of tissue, are thus magnetized in advance through the incorporation of magnetic nanoparticles, thus becoming true cellular magnetic “Legos” that can be moved and stacked using external magnets. In this new system acting as a magnetic tissue stretcher, the magnetized cells are trapped on a first micromagnet, before a second, mobile magnet traps the aggregate formed by the cells. The movement of the two magnets can stretch or compress the resulting tissue at will.

Researchers first used embryonic stem cells to test their system. They began by showing that the incorporation of nanoparticles had no impact on either the functioning of the stem cell or its capacity for differentiation. These functional magnetic stem cells were then tested in the stretcher, in which they remarkably differentiated toward cardiac cell precursors when stimulation imposed “magnetic beating” imitating the contraction of the heart. These results demonstrate the role that purely mechanical factors can play in cell differentiation.

This “all-in-one” approach, which makes it possible to build and manipulate tissue within the same system, could thus prove to be a powerful tool both for biophysical studies and tissue engineering.

* Laboratoire Matière et Systèmes Complexes (CNRS/Université Paris Diderot), in collaboration with the Laboratoire Adaptation Biologique et Vieillissement (CNRS/UPMC) and the Centre de Recherche Cardiovasculaire de Paris (Inserm/Université Paris Descartes)

Source: https://www.nature.com/
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https://eurekalert.org/

More Durable Fuel Cells For Hydrogen Electric Car

Take a ride on the University of Delaware’s (UDFuel Cell bus, and you see that fuel cells can power vehicles in an eco-friendly way. In just the last two years, Toyota, BMW and Honda have released vehicles that run on fuel cells, and carmakers such as GM, BMW and VW are working on prototypes.  If their power sources lasted longer and cost less, fuel cell vehicles could go mainstream faster. Now, a team of engineers at UD has developed a technology that could make fuel cells cheaper and more durable.

Hydrogen-powered fuel cells are a green alternative to internal combustion engines because they produce power through electrochemical reactions, leaving no pollution behind. Materials called catalysts spur these electrochemical reactions. Platinum is the most common catalyst in the type of fuel cells used in vehicles. However, platinum is expensive — as anyone who’s shopped for jewelry knows. The metal costs around $30,000 per kilogram. Instead, the UD team made a catalyst of tungsten carbide, which goes for around $150 per kilogram. They produced tungsten carbide nanoparticles in a novel way, much smaller and more scalable than previous methods.

The material is typically made at very high temperatures, about 1,500 Celsius, and at these temperatures, it grows big and has little surface area for chemistry to take place on,” explains Vlachos, professor at the Catalysis Center for Energy Innovation (UD). “Our approach is one of the first to make nanoscale material of high surface area that can be commercially relevant for catalysis.”

The researchers made tungsten carbide nanoparticles using a series of steps including hydrothermal treatment, separation, reduction, carburization and more. The results are described in a paper published in Nature Communications.

Source: https://www.udel.edu/