Nanotechnology is the ability to create and manipulate atoms and molecules on the smallest of scales. Will this emerging science revolutionize the world we live in?
Courtesy Carbophiliac Computer memory devices become cheaper, faster, and smaller every year. A team of researchers at Rice University led by James Tour has found a method of creating a new type of memory from a strip of graphite only 10 atoms thick. Individual memory bits smaller than 10 nanometers that have only two terminals will allow super thin sheets of memory to be stacked in layers, multiplying the storage capacity.
The graphene memory is able to operate in a very wide temperature range. The researchers have tested the system to minus 75 to over 200 degrees Celsius.
Researchers say that the new switches are faster than the lab's testing equipment can measure and they promise long life as well.
"We’ve tested it in the lab 20,000 times with no degradation,” said Tour. “Its lifetime is going to be huge, much better than flash memory."
"The processes uses graphene deposited on silicon via chemical vapor deposition making for easy construction that can be done in commercial volumes with methods already available," says Tour.
Here, we report that two-terminal devices consisting of discontinuous 5–10 nm thin films of graphitic sheets grown by chemical vapour deposition on either nanowires or atop planar silicon oxide exhibit enormous and sharp room-temperature bistable current–voltage behaviour possessing stable, rewritable, non-volatile and non-destructive read memories with on/off ratios of up to 107 and switching times of up to 1 mus (tested limit). Nature Materials
Source: Rice University News
John Hart, a professor at the University of Michigan, has created a super-small tribute to President-elect Obama using 150 million nanotubes. (Each one is less than a millimeter in diameter and can only be seen through a microscope.)
While electronic devices double their capacity every 18 months or so, battery capacity per volume are lucky to double every ten years. A new breakthrough by materials scientists at MIT promises to drastically decrease the size of batteries. In a battery, only the surfaces of the electrodes create electricity. The key to making lighter batteries is to make lots of surfaces but minimize the material under the surface - in other words make the electrodes as thin as possible.
MIT scientists, professors Angela Belcher, Paula Hammond and Yet-Ming Chiang have used genetically engineered living viruses to assemble thin-film nanowires as the anodes and cathodes of a flexible "battery wrap" only 100 nanometers thick. The virus is a derivative the M13 bacteriophage. It is 6 x 880 nanometers in size.
The genetically engineered battery wrap is fabricated by dipping a scaffold into three beakers. The first dip picks up a layer of polyelectrolyte which can be as thin as 100 nanometers. The second dip is into a soup of the 6 x 880 nm viruses. The viruses, which are negatively charged, stick to to the positively charged scaffold kind of like the bristles on a hair brush. These viruses, when dipped into third solution, are genetically engineered to pull cobalt-oxide and gold ions onto their surfaces.
After that, the polyelectrolyte is dried out, and the 6-nm-diameter viruses dehydrate, becoming harmlessly entombed inside a sealed compartment of inorganic cobalt and gold.
"Potentially, when we grow a lithium layer on the other side of the polyelectrolyte for the other cathode, we could use this material to make batteries as thin as 100 nm,"
Thousands of these battery layers could be stacked on top of each other and still be paper thin. Such a battery could store two or three times more energy for its size and weight than conventional batteries today. Its "wrapability" would also allow the batteries to be placed around objects rather than requiring storage compartments.
Source:Living viruses create flexible battery film EE Times
A carbon nanotube composite material called buckypaper promises to be10 times lighter than steel but up to 500 times stronger. Florida Advanced Center for Composite Technologies (FAC2T) under the direction of Ben Wang, is working to develop real-world applications for this super material.
"The U.S. military has shown a keen interest in the military applications of Wang's research; in fact, the Army Research Lab recently awarded FAC2T a $2.5-million grant, while the Air Force Office of Scientific Research awarded $1.2 million." BuckyPaper.com
Buckypaper will most likely first be used in military aircraft and cruise missiles. Its electrical conductivity would provide protection from lightning and electromagnetic interference. When the cost of producing buckypaper comes down its strength to weight ratio will help make everything lighter and stronger. Its ability to dissipate heat will also be useful in computer circuits.
I cannot imagine writing smaller than if the letters are composed by arranging individual atoms.
An Osaka University research team has demonstrated an “atomic pen” that can inscribe nano-sized text on metal by manipulating individual atoms on the surface. PinkTentacle.com
The completed text measures 2 x 2 nanometers. The procedure is described in the October 17 edition of Science magazine; "Complex Patterning by Vertical Interchange Atom Manipulation Using Atomic Force Microscopy"
Solar cells become ineffective when the sun goes down. At night, the earth radiates heat back toward the sky. Scientists at the U.S. Department of Energy's Idaho National Laboratory are working on a device to turn infrared radiation into electricity.
Billions of nanoantennas printed onto thin, inexpensive sheets will transform heat energy into electricity. The physics behind this conversion is the same as that of a radio antenna. The only difference between radiowaves and infrared light is wavelength. Antennas 1/25 the size of a human hair resonate when bombarded with heat radiation. If the resulting alternating current can be passed through a rectifier (one way valve) the current can charge up batteries. The infrared rays create alternating currents in the nanoantennas that oscillate trillions of times per second.
"Today's rectifiers can't handle such high frequencies. "We need to design nanorectifiers that go with our nanoantennas," says Kotter, noting that a nanoscale rectifier would need to be about 1,000 times smaller than current commercial devices and will require new manufacturing methods. Another possibility is to develop electrical circuitry that might slow down the current to usable frequencies." Eureka Alert
If these technical hurdles can be overcome, nanoantennas have the potential to be a cheaper, more efficient alternative to solar cells. Computer models of nanoantennas predict up to 92% efficiency (compared to solar cells around 20%).
The NYTimes has a great piece about the potential ramifications of science's latest breakthrough discoveries: nanotechnology, robotics, geo-engineering. I used to think that just about anything we could develop, would be developed. Articles like this have helped educate me that we do have a choice as a society about where and when we allow science to go. It's an interesting read.
Courtesy Zettl Research Group
A fully integrated radio receiver, orders-of-magnitude smaller than any previous radio, was made from a single carbon nanotube (CNT).
When a radio wave of a specific frequency impinges on the nanotube it begins to vibrate vigorously. An electric field applied to the nanotube forces electrons to be emitted from its tip.
This nanotube radio is over 10,000,000,000,000,000,000 times smaller than the Philco vacuum tube radio from the 1930s.
The single nanotube serves, at once, as all major components of a radio: antenna, tuner, amplifier, and demodulator. (Berkely physics research)
Videos from an electron microscope view of the nanotube radio playing two different songs are linked below.
Farm animals often carry germs that can get into our food supply. And pumping the animals full of antibiotics can cause other problems, such as breeding super bugs that are immune to the drugs. But researchers in South Carolina are taking a new approach. They are adding nanoparticles to chicken feed. The particles imitate chicken cells and attract the germs. The germs get stuck to the particles, and then get expelled harmlessly the next time the chicken poops.
Catalysts, because of its shape, can speed up chemical reactions. Platinum is a useful catalyst in fuel cells but because it costs over $2000 an ounce, it needs to be used efficiently. One way to maximize the effectiveness of platinum is to maximize its surface area.
Cornell researchers have developed a method to self-assemble metals into complex configurations with structural details about 100 times smaller than a bacterial cell by guiding metal particles into the desired form using soft polymers. NSF News
To keep nano spheres of platinum from clumping or "globbing" they are coated with an organic material known as a ligand. The innovative use of the ligands allows for the metal nanoparticles to be dissolved in a solution containing long co-polymer chains, or blocks, of molecules linked together to form a predictable pattern. After the spheres have filled in the spaces created by the co-polymer chains, heat is applied until the polymer turns to a carbon scaffold. The scaffold holds the platinum spheres in place until cooled. The carbon is then dissolved away leaving an intricate hexagonal mesh of platinum (see image above).
These metalic surfaces will also be of interest to scientists working in an area called plasmonics. Plasmonics is the study of interactions among metal surfaces, light, and density waves of electrons, known as plasmons. Improved optics applications, like lasers, displays, and lenses and better transmission of information within microchips will be some benefits.