Posts belonging to Category electronics

How To Extract Easily Gold From The Waste

Research by scientists at the University of York has demonstrated an innovative way of using a gel to extract precious metals such as silver and gold from waste and convert them into conducting nanoparticles to form a hybrid nanomaterial potentially suitable for a range of high-tech applications.

Discarded electronic devices are an ever-increasing waste stream containing high-value precious metals such as silver and gold.  Making use of this resource was the inspiration for the research by a team from the Department of Chemistry at York. Professor David Smith and Babatunde Okesola, a PhD student supported by The Wild Fund, discovered that their self-assembling gels derived from sorbitol, a simple sugar, could selectively extract precious metals from complex mixtures of other metals typical of the electronics or mining industries.



On exposure to the gel, not only were the precious metals selectively extracted, but they were also then converted into conducting nanoparticles via an in situ chemical reduction process, caused by the nanofibres of the gel network.  These conducting nanoparticles become embedded in the gel giving it enhanced electrical conductance.

Babatunde Okesola said: “Importantly, gels have properties of both solids and liquids so these conducting gels are potentially ideal to bridge between the soft, wet world of biology and the hard, dry world of electronics.  Being able to ‘wire up’ this interface will be of increasing importance in future technologies.
Dr Smith added: “We hope to go on and test our gels using real-world electronic waste, and also explore the potential applications of the resulting materials at the interface between biology and electronics.


Stabilized Perovskite Solar Cells Clear the Way To The Market

UCLA professor Yang Yang, member of the California NanoSystems Institute, is a world-renowned innovator of solar cell technology whose team in recent years has developed next-generation solar cells constructed of perovskite, which has remarkable efficiency converting sunlight to electricity.

Despite this success, the delicate nature of perovskite — a very cheap, very light, flexible, organic-inorganic hybrid material — stalled further development toward its commercialized use. When exposed to air, perovskite cells broke down and disintegrated within a few hours to few days. The cells deteriorated even faster when also exposed to moisture, mainly due to the hydroscopic nature of the perovskite.

Now Yang’s team has conquered the primary difficulty of perovskite by protecting it between two layers of metal oxide. This is a significant advance toward stabilizing perovskite solar cells. Their new cell construction extends the cell’s effective life in air by more than 10 times, with only a marginal loss of efficiency converting sunlight to electricity.

perovskite solar panel

There has been much optimism about perovskite solar cell technology,” Meng said. In less than two years, the Yang team has advanced perovskite solar cell efficiency from less than 1 percent to close to 20 percent. “But its short lifespan was a limiting factor we have been trying to improve on since developing perovskite cells with high efficiency.”

The study was published online in the journal Nature Nanotechnology. Researchers Jingbi You and Lei Meng from the Yang Lab were the lead authors on the paper.


New Cheap Catalyst To Produce Hydrogen From Water

Graphene doped with nitrogen and augmented with cobalt atoms has proven to be an effective, durable catalyst for the production of hydrogen from water, according to scientists at Rice University. The Rice lab of chemist James Tour and colleagues at the Chinese Academy of Sciences, the University of Texas at San Antonio and the University of Houston have reported the development of a robust, solid-state catalyst that shows promise to replace expensive platinum for hydrogen generation.

Tucson fuel cell

Catalysts can split water into its constituent hydrogen and oxygen atoms, a process required for fuel cells. Hydrogen electric cars as the Tucson from Hyundai are powered by fuel cells.
The latest discovery, detailed in Nature Communications, is a significant step toward lower-cost catalysts for energy production, according to the researchers.

What’s unique about this paper is that we show not the use of metal particles, not the use of metal nanoparticles, but the use of atoms,” Tour said. “The particles doing this chemistry are as small as you can possibly get.
We’re getting away with very little cobalt to make a catalyst that nearly matches the best platinum catalysts.” In comparison tests, he said the new material nearly matched platinum’s efficiency to begin reacting at a low onset voltage, the amount of electricity it needs to begin separating water into hydrogen and oxygen.


How To Manipulate Light

Electrons are so 20th century. In the 21st century, photonic devices, which use light to transport large amounts of information quickly, will enhance or even replace the electronic devices that are ubiquitous in our lives today. But there’s a step needed before optical connections can be integrated into telecommunications systems and computers: researchers need to make it easier to manipulate light at the nanoscale.

Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have done just that, designing the first on-chip metamaterial with a refractive index of zero, meaning that the phase of light can travel infinitely fast.

This new metamaterial was developed in the lab of Eric Mazur, the Balkanski Professor of Physics and Applied Physics and Area Dean for Applied Physics at SEAS, and is described in the journal Nature Photonics.

manipulated light

New zero-index material made of silicon pillar arrays embedded in a polymer matrix and clad in gold film creates a constant phase of light, which stretches out in infinitely long wavelengths

Light doesn’t typically like to be squeezed or manipulated but this metamaterial permits you to manipulate light from one chip to another, to squeeze, bend, twist and reduce diameter of a beam from the macroscale to the nanoscale,” said Mazur. “It’s a remarkable new way to manipulate light.”

Although this infinitely high velocity sounds like it breaks the rule of relativity, it doesn’t. Nothing in the universe travels faster than light carrying information — Einstein is still right about that. But light has another speed, measured by how fast the crests of a wavelength move, known as phase velocity. This speed of light increases or decreases depending on the material it’s moving through.

When light passes through water, for example, its phase velocity is reduced as its wavelengths get squished together. Once it exits the water, its phase velocity increases again as its wavelength elongates. How much the crests of a light wave slow down in a material is expressed as a ratio called the refraction index — the higher the index, the more the material interferes with the propagation of the wave crests of light. Water, for example, has a refraction index of about 1.3.

When the refraction index is reduced to zero, really weird and interesting things start to happen.


3D Printing Applied To Nanotechnology = Revolution

It seems that the in the area of technology, the new age will belong a combination of nanotechnology and 3D printing, informed Professor Hari Kishan Sahajwani during a re-union meeting of 1966-68 batch of M.Sc.-physics of Kurukshetra University (India).
3D printing
Applying 3D printing concepts to nanotechnology are doing to revolutionize nanofabrication in terms of manufacturing speed, minimizing of waste and reduction of cost. In all kinds of human services, the manufacturing technologies will be dependent on the combination of nanotechnology and 3D printing,” said Sahjwani, who goes around the country to make presentations and delivering lectures on nanotechnology.

The UK scientists have developed nanoscale specks of semiconductor called ‘Quantum Dots‘ to restore vision lost due to damaged retinas. He added that this was indication how nanotechnology aided by 3D printing will bring new vistas in medical science and treatment of diseases.

quantum dotsQuantum dots are said to have the advantages that no external power source is needed for their functioning and can be coated with a bioactive material that causes them to become lodged in only specific tissues in the retina without any side effects.

He told that 3D-printing has been successfully used to generate replicas of bioimplants like living human cartilage and future seems be bright with advanced 3D printing techniques capable of creating nanoscale complex structures.

The efforts are on to develop the techniques for more precise and accurate 3D control of electro-spun nano-jets to take current nanofabrication technologies to a new height. With research and invention, sophisticated methods and precise methods to control the nano-jets will be able to realize rapid 3D printing usable for bioscaffolds and nanofilters to have inroads into all aspects of life, it is being felt.


Nanoscope Sees Images 100,000 Times Smaller Than A Human Hair

A microscope that produces images a hundred-thousand times smaller than the width of a human hair wasn’t quite enough for Dr David Dowsett. At the Luxembourg Institute of Science and Technology (LIST), Dowsett and his team added a specially designed prototype spectrometer. They say their secondary ion mass spectrometer – or SIMS – analysis tool, is one of the most powerful in the world.

nanoscope list

A human hair is about 50 to 100 microns in diameter. The resolution of our microscope images is half a nanometer and the resolution of our SIMS images is about 10 nanometres. So, that’s about 100,000 times smaller than the diameter of a human hair“, says Dr. David Dowsett, Senior research & Technology Associate at the  Luxembourg Institute of  Science and  Technology (LIST). And it’s attracting interest from big business for it’s immense imaging and chemical mapping capabilities… including from cosmetic companies.  “So when they say ‘this is the science bit’ – that’s actually us. We’ve worked for a least one of the big pharmaceutical companies developing shampoo, so looking at whether the shampoo really penetrates into the hair,” he adds.
The precision tool’s impact could be huge for many industries, including the development of new semiconductors and Lithium ion batteries. It could also play a vital role in the the improvement and development of medicine.
We can follow where those nanoparticles have been uptaken into, for example, human cells. And also we can see whether or not a labelled drug is present within the cell, in the same place as the nanoparticle; so we can really start to test whether a delivery system is effective“, concludes Dowsett. Now he is working with his team on an improved version of the device and investigating possibilities to commercialise the development.


Powered by plants your phone is charged in 2 hours

It’s a common problem across the world. Too many smartphones and not enough electrical sockets to charge them. But thanks to three engineering students from Chile, charging your device may soon be as easy as plugging it into your favorite household plant. The idea sprouted back in 2009 during a chaotic exam week. Desperate to charge their devices, the students stepped outside to the school garden to catch a breath of fresh air and quell their frustrations. That’s when they realized that the plants producing the oxygen they were breathing also produce energy.

biocircuit_buried_in_the_soilCLICK ON THE IMAGE TO ENJOY THE VIDEO
After that, we thought, why don’t they have a socket? Because there are so many plants and living things which have the potential to produce energy, why not?” asks Evelyn Aravena,  electrical engineering and industrial automation student at  Duoc Institute in Valparaiso (Chile).

The trio began prototyping a device they call E-Kaia. It’s a biocircuit buried in the soil that harnesses energy produced by plants during photosynthesis and converts it into electricity. The team explains that the device feeds off the natural energy cycle of a plant.  “There is a complete cycle of the plant and when making this cycle, we decided to incorporate into it, then we would not affect the plant’s growth. And the biocircuit makes an acquisition and transforms it into energy to later make charges of low consumption“, adds Camila Rupchich, also student at Duoc Insitute.

The device can fully charge a smartphone in under two hours. The team is currently fine tuning the biocircuit with the hopes of launching it commercially in late 2016.

Electron Super Highway

TV screens that roll up. Roofing tiles that double as solar panels. Sun-powered cell phone chargers woven into the fabric of backpacks. A new generation of organic semiconductors may allow these kinds of flexible electronics to be manufactured at low cost, says University of Vermont physicist and materials scientist Madalina Furis. But the basic science of how to get electrons to move quickly and easily in these organic materials remains murky. To help, Furis and a team of UVM materials scientists have invented a new way to create what they are calling “an electron superhighway” in one of these materials — a low-cost blue dye called phthalocyanine — that promises to allow electrons to flow faster and farther in organic semiconductors.

Their discovery, reported Sept. 14 in the journal Nature Communications, will aid in the hunt for alternatives to traditional silicon-based electronics.


Many of these types of flexible electronic devices will rely on thin films of organic materials that catch sunlight and convert the light into electric current using excited states in the material called “excitons.” Roughly speaking, an exciton is a displaced electron bound together with the hole it left behind. Increasing the distance these excitons can diffuse — before they reach a juncture where they’re broken apart to produce electrical current — is essential to improving the efficiency of organic semiconductors.

Using a new imaging technique, the UVM team was able to observe nanoscale defects and boundaries in the crystal grains in the thin films of phthalocyanine roadblocks in the electron highway.We have discovered that we have hills that electrons have to go over and potholes that they need to avoid,” Furis explains.

To find these defects, the UVM team — with support from the National Science Foundation — built a scanning laser microscope, “as big as a table” Furis says.

Marrying these two techniques together is new; it’s never been reported anywhere,” says Lane Manning ’08 a doctoral student in Furis’ lab and co-author on the new study. The scientists have now a deeper understanding of how the arrangement of molecules and the boundaries in the crystals influence the movement of excitons. It’s these boundaries that form a “barrier for exciton diffusion,” the team writes.


Electronic Tatoo On The Skin Monitors Vital Signals

A team of researchers in the Cockrell School of Engineering at the University of Texas at Austin has invented a method for producing inexpensive and high-performing wearable patches that can continuously monitor the body’s vital signs for human health and performance tracking, potentially outperforming traditional monitoring tools such as cardiac event monitors. Led by Assistant Professor Nanshu Lu, the team’s manufacturing method aims to construct disposable tattoo-like health monitoring patches for the mass production of epidermal electronics, a popular technology that Lu helped develop in 2011.

The team’s breakthrough is a repeatable “cut-and-paste” method that cuts manufacturing time from several days to only 20 minutes. The researchers believe their new method is compatible with roll-to-roll manufacturing — an existing method for creating devices in bulk using a roll of flexible plastic and a processing machine.

Reliable, ultrathin wearable electronic devices that stick to the skin like a temporary tattoo are a relatively new innovation. These devices have the ability to pick up and transmit the human body’s vital signals, tracking heart rate, hydration level, muscle movement, temperature and brain activity. Although it is a promising invention, a lengthy, tedious and costly production process has until now hampered these wearables’ potential.

epidermal electronics

One of the most attractive aspects of epidermal electronics is their ability to be disposable,” Lu said. “If you can make them inexpensively, say for $1, then more people will be able to use them more frequently. This will open the door for a number of mobile medical applications and beyond.”

The UT Austin method is the first dry and portable process for producing these electronics, which, unlike the current method, does not require a clean room, wafers and other expensive resources and equipment. Instead, the technique relies on freeform manufacturing, which is similar in scope to 3-D printing but different in that material is removed instead of added.

The researchers published a paper on their patent-pending process in Advanced Materials.


Energy From Trees Can Power Everything

Researchers Emily Cranston and Igor Zhitomirsky from the Faculty of Engineering at McMaster University (Canada)  are turning trees into energy storage devices capable of powering everything from a smart watch to a hybrid car.

The scientists are using cellulose, an organic compound found in plants, bacteria, algae and trees, to build more efficient and longer-lasting energy storage devices or capacitors. This development paves the way toward the production of lightweight, flexible, and high-power electronics, such as wearable devices, portable power supplies and hybrid and electric vehicles.

treesUltimately the goal of this research is to find ways to power current and future technology with efficiency and in a sustainable way,” says Cranston, whose joint research was recently published in Advanced Materials.This means anticipating future technology needs and relying on materials that are more environmentally friendly and not based on depleting resources“.

Cellulose offers the advantages of high strength and flexibility for many advanced applications; of particular interest are nanocellulose-based materials. The work by Cranston, an assistant chemical engineering professor, and Zhitomirsky, a materials science and engineering professor, demonstrates an improved three-dimensional energy storage device constructed by trapping functional nanoparticles within the walls of a nanocellulose foam.


How To Spray Solar Cells

A new study out of St. Mary’s College of Maryland puts us closer to do-it-yourself spray-on solar cell technology—promising third-generation solar cells utilizing a nanocrystal ink deposition that could make traditional expensive silicon-based solar panels a thing of the past.

In a 2014 study, published in the journal Physical Chemistry Chemical Physics, St. Mary’s College of Maryland energy expert Professor Troy Townsend introduced the first fully solution-processed all-inorganic photovoltaic technology.

spray-on solar cells
While progress on organic thin-film photovoltaics is rapidly growing, inorganic devices still hold the record for highest efficiencies which is in part due to their broad spectral absorption and excellent electronic properties. Considering the recorded higher efficiencies and lower cost per watt compared to organic devices, combined with the enhanced thermal and photo stability of bulk-scale inorganic materials, Townsend, in his 2014 study, focused on an all-inorganic based structure for fabrication of a top to bottom fully solution-based solar cell.

A major disadvantage compared to organics, however, is that inorganic materials are difficult to deposit from solution. To overcome this, Townsend synthesized materials on the nanoscale. Inorganic nanocrystals encased in an organic ligand shell are soluble in organic solvents and can be deposited from solution (i.e., spin-, dip-, spray-coat) whereas traditional inorganic materials require a high temperature vacuum chamber. The solar devices are fabricated from nanoscale particle inks of the light absorbing layers, cadmium telluride/cadmium selenide, and metallic inks above and below. This way, the entire electronic device can be built on non-conductive glass substrates using equipment you can find in your kitchen.

When you spray on these nanocrystals, you have to heat them to make them work,” explained Townsend, “but you can’t just heat the crystals by themselves, you have to add a sintering agent and that, for the last 40 years, has been cadmium chloride, a toxic salt used in commercial thin-film devices. No one has tested non-toxic alternatives for nanoscale ink devices, and we wanted to explore the mechanism of the sintering process to be able to implement safer salts.”


“Chewing gum” Material 3 Times Stronger Than Steel

Creating futuristic, next generation materials called ‘metallic glass’ that are ultra-strong and ultra-flexible will become easier and cheaper, based on UNSW Australia research that can predict for the first time which combinations of metals will best form these useful materials.

Just like something from science fiction – think of the Liquid-Metal robot assassin in the Terminator films – these materials behave more like glass or plastic than metal.

While still being metals, they become as malleable as chewing gum when heated and can be easily moulded or blown like glass. They are also three times stronger and harder than ordinary metals, on average, and are among the toughest materials known.


liquid_terminatorThe Terminator‘s Liquid Metal Man: While still being metals, they become as malleable as chewing gum when heated and can be easily moulded or blown like glass.

They have been described as the most significant development in materials science since the discovery of plastics more than 50 years ago,” says study author, UNSW’s Dr Kevin Laws.

Most metals are crystalline when solid, with their atoms arranged in a highly organised and regular manner. Metallic glass alloys, however, have a highly disordered structure, with the atoms arranged in a non-regular way.