Solar cells made from common materials
Solar cells for everyone
Courtesy Dominic
Solar cells produce less than 1/1000 of the Earth's electricity. This is mainly because they are expensive and are made from rare, hard to obtain materials.
An IBM research team, managed by David Mitzi, is working on photovoltaic cells that are made from common materials.
The new solar cells are also cheaper to manufacture, using a “printing” technique that uses a hydrazine solution containing copper and tin with nanoparticles of zinc dispersed within it. The solution is then spin-coated and heat treated in the presence of selenium or sulfur vapor. PhysOrg
9.6% Efficiency
This new material, called kesterite, was 6.8% efficient in 2009. IBM increased the efficiency to 9.8% and is planning to increase the efficiency above 11 per cent, which is equal to or better than the traditional solar cells.
Abstract of published paper: High-Efficiency Solar Cell with Earth-Abundant Liquid-Processed Absorber Advanced Materials
Tags : U.S. Ski Team members Julia Mancuso, Ted Ligety and Scott Macartney, and Katharine Flores, an associate professor in the Department of Materials Science and Engineering at Ohio State University, explain how the materials used to make skis play a vital role in their performance on the mountain.
Liquid Glass
Courtesy HustvedtSoon almost every product you purchase will be coated with liquid glass. It repels bacteria, water and dirt, is highly flexible and breathable, and is easy to clean using only water or a simple wipe with a damp cloth.
Nanopool, who makes "Liquid Glass" says it is available in Germany now, and will be in the UK early in 2010.
Quantum force bonding
Using their secret process, NanoPool extracts silicon dioxide molecules from glass and mixes them with water or ethanol. When sprayed on various materials, a 100 nanometer coating offers protection against bacteria, graffiti, stains and is food safe and environmentally friendly.
Source:
Spray-on liquid glass is about to revolutionize almost everything PhysOrg.com
Graphene
Courtesy Carbophiliac
Graphene is great
Graphene is a single atom thick layer of carbon atoms in a honeycomb like arrangement (read more about graphene here in ScienceBuzz.org)
Graphene transistors are the fastest
Transistors are like valves that can turn the flow of electricity off and on. Computers can use transistors and logic circuits to solve all kinds of problems. These problems can be solved faster if the transistors can turn on and off faster. Transistors made out of graphene now can switch on and off 100 billion times per second (100 GigaHertz). State-of-the-art silicon transistors of the same gate length have a switching frequency of about 40 GigaHertz.
IBM develops next-generation transistors
IBM just announced their breakthrough in the magazine Science.
Uniform and high-quality graphene wafers were synthesized by thermal decomposition of a silicon carbide (SiC) substrate. The graphene transistor itself utilized a metal top-gate architecture and a novel gate insulator stack involving a polymer and a high dielectric constant oxide. The gate length was modest, 240 nanometers, leaving plenty of space for further optimization of its performance by scaling down the gate length. ScienceDaily
Flash memory: Today's content king.
Courtesy Nrbelex
MRAM
MRAM (magnetoresistive random access memory) flips the magnetisation of a region 180 degrees relative to another permanently magnetised region to store a 0 or a 1. MRAM is nanosecond fast but if made too small and close together will "cross talk".
FeRAM
FeRAM (ferroelectric random access memory) use small external electric fields to polarize ferroelectric crystals. FeRAMs low energy requirement and speed advantage is offset by the requirement that every memory bit requires a space hogging capacitor.
PCRAM
PCRAM (phase-change random access memory) use laser light or current to change a materials structure. If the current pulse is long, the material orders itself into its crystalline state (a conductor). If the pulse is short, the material cools abruptly into the amorphous state (an insulator). These memory regions can be made quite small, but the downside is that the melting requires lots of energy.
RRAM
RRAM (resistive random access memory) use high voltages to drive off or reabsorb oxygen bound within molecules like titanium oxide. When the oxygen leaves, it leaves behind holes in the crystal and excess electrons that are available for conduction. This process requires almost no electrical current, making them very energy efficient. Another exciting property is that RRAMs can represent more than a 0 or 1. They are able to adopt any number of values for their resistance (memristors) which could make them models for the analogue computational elements (synapses) inside the human brain.
Racetrack memory
Racetrack memory moves tiny domains of magnetism along wires. The domains are moved along the wire by a current and written or read when they pass sensor heads. If the wires can be coiled into 3 D, the memory per volume will increase several hundred times.
Source: New Scientist
Synthetic biology pioneer, Andrew Hessel, explains how building blocks of DNA snippets will be assembled into customized living organisms
.
Medicine without patents
Andrew Hessel hopes that an open source approach in pharmacology will produce safe, effective, and individually personalized medicines quickly and inexpensively. Hessel likens the exponential advances in synthetic biology to the boom in the electronics industry.
Test tube sized factories
One big difference, though, is that biological manufacuring does not require expensive refining, huge factories, or expensive tools. Biological organisms are alive and can self assemble complex structures from basic ingredients.
Foundational work, including the standardization of DNA-encoded parts and devices, enables them to be combined to create programs to control cells.
- Cells are being engineered to consume agricultural products and produce liquid fuels.
- Bacteria and yeast can be re-engineered for the low cost production of drugs. (Artemisinin, Lipitor)
- Bacteria and T-cells can be rewired to circulate in the body and identify and treat diseased cells and tissues. BioBricks.org
DIY BIO 4 Beginners
Eric Fernandez has a blog for do-it-yourself types like 23-year-old Kay Aull who set up a do it yourself DNA lab for genotyping her GFE gene in her closet! Be sure to check the archives for more than a hundred informative DIY Bio posts like this one by Make's, Mac Cowell.
Gene hacking and biofabs
Costs are coming down fast and genetic synthesis or gene fabrication is a cottage industry. Biofabs like GeneArt, Blue Heron, DNA2.0, and Codon Devices can deliver a synthesized product from an e-mailed description almost over night. Synthetic biologists envision writing the DNA code for such products the way computer programmers write software.
Catolog for genetic parts
Genetic programming now has several well developed languages allowing large data bases of biological modules.
The Registry of Standard Biological Parts is a continuously growing collection of genetic parts that can be mixed and matched to build synthetic biology devices and systems. Founded in 2003 at MIT, the Registry is part of the Synthetic Biology community's efforts to make biology easier to engineer. It provides a resource of available genetic parts to iGEM teams and academic labs.
iGEM synthetic biology contest for students
The International Genetically Engineered Machine competition (iGEM) is the premiere undergraduate Synthetic Biology competition. Teams participating and over 1200 participants will all specify, design, build, and test simple biological systems made from standard, interchangeable biological parts. If you go to this iGEM results page you will find video links for the winning presentations. You can read team abstracts of the iGEM projects here.
Carbon nanotubes as energy storage
Courtesy ghutchis
Carbon nanotube springs may be better than batteries
What does a mousetrap have in common with a wind-up clock? A spring. A spring can provide energy to run a clock for days. A mouse trap spring can deliver a quick, deadly energy burst. Unlike batteries, energy stored in a spring can last hundreds of years and is usually not diminished by extreme cold or heat.
1000 times the energy density of a steel spring
MIT scientist, Carol Livermore, "did a combination of mathematical analysis and small-scale laboratory testing to determine the potential of carbon nanotubes to be used as springs for energy storage" MITnews.
Lots of basic research and engineering challenges remain
The nanospring concept is sound in theory and may even be patented. Working out the details to provide a working device using carbon-nano-tubes to store and re-deliver energy will require plenty of additional basic research, followed by engineering work.
Sources:
- "Storing elastic energy in carbon nanotubes," by F. A. Hill, Carol Livermore et al, in Journal of Micromechanics and Microengineering, Aug. 26, 2009, and
- "Modeling mechanical energy storage in springs based on carbon nanotubes," F. A. Hill, Carol Livermore et al, in Nanotechnology, June 3, 2009
- Small springs could provide big power MITnews.
.
Single molecule, one million times smaller than a grain of sand, pictured for first time
Read more about this at MailOnline or read the IBM Zurich press release.
We demonstrate imaging of molecules with unprecedented atomic resolution by probing the short-range chemical forces with use of noncontact atomic force microscopy. The key step is functionalizing the microscope’s tip apex with suitable, atomically well-defined terminations, such as CO molecules. Science Magazine
Graphene is again proving to be the super material. Micro ribbons of graphene are out performing copper wires, both in current carrying capacity and in heat dissipation.
In widths as narrow as 16 nanometers, graphene has a current carrying capacity approximately a thousand times greater than copper – while providing improved thermal conductivity. Georgia Tech
The new I-35W bridge: now bigger, stronger, and greener.
Courtesy anjouwuEver stand on a sidewalk and wonder about the concrete beneath your feet? Where did it come from, and how did this hard grey material get to be pretty much everywhere? Though you may not think about it at all, concrete is used more than any other building material in the world. In fact, concrete is so ubiquitous that the production of concrete contributes 5% of the world's human-caused carbon dioxide emissions to the atmosphere.
Add it all up and it starts to look like concrete is more than just the stuff of sidewalks and building blocks. Concrete is a V.I.P. (which is how I like to refer to Very Important Polluters).
While concrete is a huge contributor of CO2, it also has loads of potential to be an innovative and important "green" material that helps us to build stronger and more environmentally friendly roads, bridges and buildings. This really great article from the New York Times science section explains the basics of concrete chemistry, and how new concrete mixes are being developed that are not just stronger and better for buildings, but that also can scrub carbon from the air.
Here in the Twin Cities we have our own example of cutting-edge concrete in the I-35W bridge, which was built to replace the bridge that collapsed in 2007, killing 13 people. You might not realize it as you pass over this bridge, but it's made of many different mixes of concrete, each developed to do a particular job.
Some of the concrete in the I-35W bridge was mixed and cured (that's what they call the hardening process) to be strong and stable, others to resist the road salts and other effects of weather and climate in Minnesota. The wavy concrete sculptures on the bridge even scrub pollutants from the air, In fact, they stay white because of a chemical process that uses the sun to help break down staining pollutants. Who knew concrete could be so fascinating?!
More Than You Ever Wanted to Know About Concrete
Subscribe
I want to learn about
Science Buzz is supported by the National Science Foundation.Copyright © Science Museum of Minnesota, 2004-2010, except where noted.
Add a new comment