Posts belonging to Category green power



Ninety Nine Percent Of Sunlight May Be Source To Electricity

Rice University scientists have created a one-step process for producing highly efficient materials that let the maximum amount of sunlight reach a solar cell. The Rice lab of chemist Andrew Barron found a simple way to etch nanoscale spikes into silicon that allows more than 99 percent of sunlight to reach the cells’ active elements, where it can be turned into electricity. The more light absorbed by a solar panel’s active elements, the more power it will produce. But the light has to get there. Coatings in current use that protect the active elements let most light pass but reflect some as well. Various strategies have cut reflectance down to about 6 percent, Barron said, but the anti-reflection is limited to a specific range of light, incident angle and wavelength.

Enter black silicon, so named because it reflects almost no light. Black silicon is simply silicon with a highly textured surface of nanoscale spikes or pores that are smaller than the wavelength of light. The texture allows the efficient collection of light from any angle — from sunrise to sunset

Barron and Lu have replaced a two-step process that involved metal deposition and electroless chemical etching with a single step that works at room temperature.

The research by Barron and Rice graduate student and lead author Yen-Tien Lu appears in the Royal Society of Chemistry’s Journal of Materials Chemistry A.
Source: http://news.rice.edu/

Sand-based Lithium Ion Batteries That Outperform Standard by 3 times

Researchers at the University of California, Riverside’s Bourns College of Engineering have created a lithium ion battery that outperforms the current industry standard by three times. The key material: sand. Yes, sand.

This is the holy grail – a low cost, non-toxic, environmentally friendly way to produce high performance lithium ion battery anodes,” said Zachary Favors, a graduate student working with Cengiz and Mihri Ozkan, both engineering professors at UC Riverside.
The idea came to Favors six months ago. He was relaxing on the beach after surfing in San Clemente, Calif. when he picked up some sand, took a close look at it and saw it was made up primarily of quartz, or silicon dioxide.

His research is centered on building better lithium ion batteries, primarily for personal electronics and electric vehicles. He is focused on the anode, or negative side of the battery. Graphite is the current standard material for the anode, but as electronics have become more powerful graphite’s ability to be improved has been virtually tapped out.
Researchers are now focused on using silicon at the nanoscale, or billionths of a meter, level as a replacement for graphite. The problem with nanoscale silicon is that it degrades quickly and is hard to produce in large quantities.
Findings have been published in in the journal Nature Scientific Reports.
Source: http://ucrtoday.ucr.edu/

Nanotechnology: Food And Drug Administration Rules

Today, 3 final guidances and one draft guidance were issued by the U.S. Food and Drug Administration (FDA) providing greater regulatory clarity for industry on the use of nanotechnology in FDA-regulated products.
One final guidance addresses the agency’s overall approach for all products that it regulates, while the two additional final guidances and the new draft guidance provide specific guidance for the areas of foods, cosmetics and food for animals, respectively.

Nanotechnology is an emerging technology that allows scientists to create, explore and manipulate materials on a scale measured in nanometers—particles so small that they cannot be seen with a regular microscope. The technology has a broad range of potential applications, such as improving the packaging of food and altering the look and feel of cosmetics.

SILVER NANOPARTICLES

Our goal remains to ensure transparent and predictable regulatory pathways, grounded in the best available science, in support of the responsible development of nanotechnology products,” said FDA Commissioner Margaret A. Hamburg, M.D. “We are taking a prudent scientific approach to assess each product on its own merits and are not making broad, general assumptions about the safety of nanotechnology products.”

The 3 final guidance documents reflect the FDA’s current thinking on these issues after taking into account public comment received on the corresponding draft guidance documents previously issued (draft agency guidance in 2011; and draft cosmetics and foods guidances in 2012).

The FDA does not make a categorical judgment that nanotechnology is inherently safe or harmful, and will continue to consider the specific characteristics of individual products.
All 4 guidance documents encourage manufacturers to consult with the agency before taking their products to market. Consultations with the FDA, early in the product development process help to facilitate a mutual understanding about specific scientific and regulatory issues relevant to the nanotechnology product, and help address questions related to safety, effectiveness, public health impact and/or regulatory status of the product.
Source: http://www.fda.gov/

Ninety Nine Percent Of Sunlight May Be Source To Electricity

Rice University scientists have created a one-step process for producing highly efficient materials that let the maximum amount of sunlight reach a solar cell. The Rice lab of chemist Andrew Barron found a simple way to etch nanoscale spikes into silicon that allows more than 99 percent of sunlight to reach the cells’ active elements, where it can be turned into electricity. The more light absorbed by a solar panel’s active elements, the more power it will produce. But the light has to get there. Coatings in current use that protect the active elements let most light pass but reflect some as well. Various strategies have cut reflectance down to about 6 percent, Barron said, but the anti-reflection is limited to a specific range of light, incident angle and wavelength.

Enter black silicon, so named because it reflects almost no light. Black silicon is simply silicon with a highly textured surface of nanoscale spikes or pores that are smaller than the wavelength of light. The texture allows the efficient collection of light from any angle — from sunrise to sunset

Barron and Lu have replaced a two-step process that involved metal deposition and electroless chemical etching with a single step that works at room temperature.

The research by Barron and Rice graduate student and lead author Yen-Tien Lu appears in the Royal Society of Chemistry’s Journal of Materials Chemistry A.
Source: http://news.rice.edu/

A Glass Of Milk So White…

The Project on Emerging Nanotechnologies (PEN) revealed a few weeks ago that there are over 1,600 nanotechnology-based products on the market today — and that the United States Food and Drug Administration (FDA) lacks the authority to regulate them.Some of these nanotechnological innovations — which refer to particles less than 100 nanometers wide, or approximately 1/800th the diameter of a strand of human hair — are likely harmless, such as embedded silver particles in athletic socks and underwear. According to SmartSilver Anti-Odor Nanotechnology Underwear, the microscopic silver particles are “strongly antibacterial to a wide range of pathogens, absorb sweat, and by killing bacteria help eliminate unpleasant foot odor.”

However, the PEN database also includes 96 nanotechnology-infused items currently stocked on grocery store shelves, and none of these items listed their nanotechnology among their ingredients. Included on the list are Dannon Greek Plain Yogurt, Hershey’s Bliss Dark Chocolate, Kraft’s American Cheese Singles, and Rice Dream Rice Drink, all of which contain nanoparticles of titanium dioxide.

Titanium dioxide — often referred to as “the perfect white” or “the whitest white” — is used as a pigment because its refractive index is extremely high. It has long been present in paints, plastics, paper, toothpaste, and pearlescent cosmetics, but researchers recently discovered the benefits of adding it to skim milk.

According to David Barbano, a professor at Cornell University’s Department of Food Science, “suspension of titanium dioxide in skim milk made the milk whiter, which resulted in improved sensory scores for appearance, creamy aroma, and texture… There is clearly a need to develop a whitener for fat-free milk other than titanium dioxide to provide processors with an ingredient option that would improve sensory properties and provide a nutritional benefit.”

Source: http://www.nanotechproject.org/

Cheaper, Lighter Solar Cells

Think those flat, glassy solar panels on your neighbour’s roof are the pinnacle of solar technology? Think again.
Researchers in the University of Toronto’s Edward S. Rogers Sr. Department of Electrical & Computer Engineering have designed and tested a new class of solar-sensitive nanoparticle that outshines the current state of the art employing this new class of technology. This new form of solid, stable light-sensitive nanoparticles, called colloidal quantum dots, could lead to cheaper and more flexible solar cells, as well as better gas sensors, infrared lasers, infrared light emitting diodes and more.

The field of colloidal quantum dot photovoltaics requires continued improvement in absolute performance, or power conversion efficiency,” said Sargent. “The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels.”.

This research was conducted in collaboration with Dalhousie University, King Abdullah University of Science and Technology and Huazhong University of Science and Technology.
The work, led by post-doctoral researcher Zhijun Ning and Professor Ted Sargent, was published this week in Nature Materials.
Source: http://media.utoronto.ca/

Your Jacket Will Be The Power Source

Imagine being able to carry all the juice you needed to power your MP3 player, smartphone and electric car in the fabric of your jacket? Sounds like science fiction, but it may become a reality thanks to breakthrough technology developed at a University of Central Florida research lab. So far electrical cables are used only to transmit electricity. However, nanotechnology scientist and professor Jayan Thomas and his Ph.D. student Zenan Yu have developed a way to both transmit and store electricity in a single lightweight copper wire.

It’s an interesting idea,” Thomas said. “When we did it and started talking about it, everyone we talked to said, Hmm, never thought of that. It’s unique.’” Copper wire is the starting point but eventually, Thomas said, as the technology improves, special fibers could also be developed with nanostructures to conduct and store energy.

More immediate applications could be seen in the design and development of electrical vehicles, space-launch vehicles and portable electronic devices. By being able to store and conduct energy on the same wire, heavy, space-consuming batteries could become a thing of the past. It is possible to further miniaturize the electronic devices or the space that has been previously used for batteries could be used for other purposes. In the case of launch vehicles, that could potentially lighten the load, making launches less costly, Thomas said.

In other words, Thomas and his team created a supercapacitor on the outside of the copper wire. Supercapcitors store powerful energy, like that needed to start a vehicle or heavy-construction equipment.

Although more work needs to be done, Thomas said the technique should be transferable to other types of materials. That could lead to specially treated clothing fibers being able to hold enough power for big tasks. For example, if flexible solar cells and these fibers were used in tandem to make a jacket, it could be used independently to power electronic gadgets and other devices.

Source: http://today.ucf.edu/

Mimic Nature To Build Man-made Molecular Systems

Using molecules of DNA like an architectural scaffold, Arizona State University (ASU) scientists, in collaboration with colleagues at the University of Michigan, have developed a 3-D artificial enzyme cascade that mimics an important biochemical pathway, a major breakthrough for future biomedical and energy applications.


Remaking an artificial enzyme pair in the test tube and having it work outside the cell is a big challenge for DNA nanotechnology. To meet the challenge, they first made a DNA scaffold that looks like several paper towel rolls glued together. Using a computer program, they were able to customize the chemical building blocks of the DNA sequence so that the scaffold would self-assemble. Next, the two enzymes were attached to the ends of the DNA tubes. In the middle of the DNA scaffold, a research team led by ASU professor Hao Yan affixed a single strand of DNA, with the molecule called NAD+ tethered to the end like a ball and string. Yan refers to this as a swinging arm, which is long, flexible and dexterous enough to rock back and forth between the enzymes to carry out a chemical reaction

We look to Nature for inspiration to build man-made molecular systems that mimic the sophisticated nanoscale machineries developed in living biological systems, and we rationally design molecular nanoscaffolds to achieve biomimicry at the molecular level,” Yan said, who holds the Milton Glick Chair in the ASU Department of Chemistry and Biochemistry.
An even loftier and more valuable goal is to engineer highly programmed cascading enzyme pathways on DNA nanostructure platforms with control of input and output sequences. Achieving this goal would not only allow researchers to mimic the elegant enzyme cascades found in nature and attempt to understand their underlying mechanisms of action, but would facilitate the construction of artificial cascades that do not exist in nature,” said Yan.
The findings were published in the journal Nature Nanotechnology.
Source: https://asunews.asu.edu/

Car Waste Heat Transformed Into Electricity

Thermoelectric materials can turn a temperature difference into an electric voltage. Among their uses in a variety of specialized applications: generating power on space probes and cooling seats in fancy cars.

University of Miami physicist Joshua Cohn and his collaborators report new surprising properties of a metal named lithium purple-bronze (LiPB) that may impact the search for materials useful in power generation, refrigeration, or energy detection.

If current efficiencies of thermoelectric materials were doubled, thermoelectric coolers might replace the conventional gas refrigerators in your home,” said Cohn, professor and chairman of the UM Department of Physics in the College of Arts and Sciences and lead author of the study. “Converting waste heat into electric power, for example, using vehicle exhaust, is a near-termgreen’ application of such materials.”
The findings are published in the journal Physical Review Letters.

Source: http://www.miami.edu/

World’s Smallest, Fastest Nanomotor

Researchers at the Cockrell School of Engineering at The University of Texas at Austin have built the smallest, fastest and longest-running tiny synthetic motor to date. The team’s nanomotor is an important step toward developing miniature machines that could one day move through the body to administer insulin for diabetics when needed, or target and treat cancer cells without harming good cells.

With the goal of powering these yet-to-be invented devices, UT Austin engineers focused on building a reliable, ultra-high-speed nanomotor that can convert electrical energy into mechanical motion on a scale 500 times smaller than a grain of salt.

Mechanical engineering assistant professor Donglei “Emma” Fan led a team of researchers in the successful design, assembly and testing of a high-performing nanomotor in a nonbiological setting. The team’s three-part nanomotor can rapidly mix and pump biochemicals and move through liquids, which is important for future applications. One amazing arena of application for this nanomotor is the field of nanoelectromechanical systems (NEMS), where such a machine will be able to push forward the frontiers of cheaper and more energy efficient systems.
The team’s study was published in the April issue of Nature Communications.

Source: http://www.engr.utexas.edu/