Category Archives: Nanotechnology

Nanoscientists Create Biological Switch

Nanoscientists Create Biological Switch From Spinach Molecule:

The scientists used a scanning tunneling microscope to image chlorophyll-a and then injected it with a single electron to manipulate the molecule into four positions, ranging from straight to curved, at varying speeds. Though the Ohio University team and others have created two-step molecule switches using scanning tunneling microscope manipulation in the past, the new experiment yields a more complex multi-step switch on the largest organic molecule to date.

The work has immediate implications for basic science research, as the configuration of molecules and proteins impacts biological functions. The study also suggests a novel route for creating nanoscale logic circuits or mechanical switches for future medical, computer technology or green energy applications, said Hla, an associate professor of physics.

Great Nanotechnology Overview

Reporting Risk Assessment of Nanotechnology: A reporter’s guide to sources and research issues (pdf) by Trudy E. Bell:

The article discusses how reporters should investigate the risks with nanotechnology, and in doing so provides a good introduction to concepts in nanotechnology:

If engineered nanomaterials have physical properties different from their bulk counterparts, might they also pose new risks to human health in their manufacture, use, and disposal?

As yet, no one knows. Current data basically suggest “it depends.” But researchers both in government and private
industry are keen to find out.

The potential for nanotechnology is amazing but as we have said before the risks presented by nanotechnology also need careful study.

At the nanoscale, fundamental mechanical, electronic, optical, chemical, biological, and other properties may differ significantly from properties of micrometer-sized particles or bulk materials.

One reason is surface area. Surface area counts because most chemical reactions involving solids happen at the surfaces, where chemical bonds are incomplete. The surface area of a cubic centimeter of a solid material is 6 square centimeters—about the same as one side of half a stick of gum. But the surface area of a cubic centimeter of 1-nm particles in an ultrafine powder is 6,000 square meters—literally a third larger than a football field.

Nanocars

Nano Car image

‘Nanocar’ with buckyball wheels paves way for other molecular machines

“The synthesis and testing of nanocars and other molecular machines is providing critical insight in our investigations of bottom-up molecular manufacturing,” said one of the two lead researchers, James M. Tour, the Chao Professor of Chemistry, professor of mechanical engineering and materials science and professor of computer science at Rice University. “We’d eventually like to move objects and do work in a controlled fashion on the molecular scale, and these vehicles are great test beds for that. They’re helping us learn the ground rules.”

The nanocar consists of a chassis and axles made of well-defined organic groups with pivoting suspension and freely rotating axles. The wheels are buckyballs, spheres of pure carbon containing 60 atoms apiece. The entire car measures just 3-4 nanometers across, making it slightly wider than a strand of DNA. A human hair, by comparison, is about 80,000 nanometers in diameter.

Semiconductor Paint

Paint-on semiconductor outperforms chips

Researchers at the University of Toronto have created a semiconductor device that outperforms today’s conventional chips — and they made it simply by painting a liquid onto a piece of glass.

The finding, which represents the first time a so-called “wet” semiconductor device has bested traditional, more costly grown-crystal semiconductor devices, is reported in the July 13 issue of the journal Nature.

Like so much advance research funding by government, in this case the Canadian government, is crucial:
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Bacteria Sprout Conducting Nanowires

photo of Bacteria with Conducting Nanowires

Bacteria made to sprout conducting nanowires by Mason Inman

Bacteria that use sugars and sewage as fuel are being investigated as a pollution-free source of electricity. They feed by plucking electrons from atoms in their fuel and dumping them onto the oxygen or metal atoms in the mixture. The transfer of the electrons creates a current, and connecting the bacteria to an electrode in a microbial fuel cell will generate electricity, although not necessarily very efficiently.

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Large-Scale, Cheap Solar Electricity

Photo of solar sheet manufacturing

Large-Scale, Cheap Solar Electricity by Kevin Bullis

This week, Nanosolar, a startup in Palo Alto, CA, announced plans to build a production facility with the capacity to make enough solar cells annually to generate 430 megawatts. This output would represent a substantial portion of the worldwide production of solar energy.

According to Nanosolar’s CEO Martin Roscheisen, the company will be able to produce solar cells much less expensively than is done with existing photovoltaics because its new method allows for the mass-production of the devices. In fact, maintains Roscheisen, the company’s technology will eventually make solar power cost-competitive with electricity on the power grid.

Nanosolar also announced this week more than $100 million in funding from various sources, including venture firms and government grants. The company was founded in 2001 and first received seed money in 2003 from Google’s founders Larry Page and Sergey Brin.

Information on the nanotechnology involved from the Nanosolar site.

Recharge Batteries in Seconds

MIT researchers are working on battery technology based on capacitor technology and nanotechnology.

Super Battery (video also available):

Rechargable and disposable batteries use a chemical reaction to produce energy. “That’s an effective way to store a large amount of energy,” he says, “but the problem is that after many charges and discharges … the battery loses capacity to the point where the user has to discard it.”

But capacitors contain energy as an electric field of charged particles created by two metal electrodes. Capacitors charge faster and last longer than normal batteries. The problem is that storage capacity is proportional to the surface area of the battery’s electrodes, so even today’s most powerful capacitors hold 25 times less energy than similarly sized standard chemical batteries.

The researchers solved this by covering the electrodes with millions of tiny filaments called nanotubes.
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This technology has broad practical possibilities, affecting any device that requires a battery. Schindall says, “Small devices such as hearing aids that could be more quickly recharged where the batteries wouldn’t wear out; up to larger devices such as automobiles where you could regeneratively re-use the energy of motion and therefore improve the energy efficiency and fuel economy.”

Previous post: MIT Energy Storage Using Carbon Nanotubes

Nanoscale Fractal Molecule

Scientists Create the First Synthetic Nanoscale Fractal Molecule by Andrea Gibson:

The molecule, developed by researchers at the University of Akron, Ohio University and Clemson University, eventually could lead to new types of photoelectric cells, molecular batteries and energy storage, according to the scientists, whose study was published online today by the journal Science.

A University of Akron research team led by Vice President for Research George Newkome used molecular self-assembly techniques to synthesize the molecule in the laboratory. The molecule, bound with ions of iron and ruthenium, forms a hexagonal gasket.

Ohio University physicists Saw-Wai Hla and Violeta Iancu, who specialize in imaging objects at the nanoscale, confirmed the creation of the man-made fractal. To capture the image, the physicists sprayed the molecules onto a piece of gold, chilled them to minus 449 degrees Fahrenheit to keep them stable, and then viewed them with a scanning tunneling microscope.

Nanowired at Berkeley

Nanowires

Photo: Cross-sectional scanning electron micrograph image of vertically-grown silicon nanowires off of a silicon substrate. (courtesy the researchers)

Nanowired by David Pescovitz:

“We’re attacking three fundamental issues,” Yang says. “Can we make these building blocks of nanodevices? Can we identify and harness useful physical properties in them? And can we integrate them in parallel? Individual devices are fundamentally interesting. But more importantly, we need massive numbers of them to work together as one system.”
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The researchers demonstrated that minute voltages could control the flow of ions through the nanoscale plumbing system. In the future, the same technique might be used to shuttle proteins or pieces of DNA from a biological sample through the tubes in a lab-on-a-chip. Yang is currently developing a technique to conduct optical sensing within the nanofluidic channels so that the whole lab is self-contained in one device.

Nanospheres Targeting Cancer at MIT

Nanospheres targeting cancer cells

Single-Shot Chemo – Nanospheres that target cancer cells and gradually release drugs could make treatment safer and more effective

Photo – Three prostate cancer cells have taken up fluorescently labeled nanoparticles (shown in red). The cells’ nuclei and cytoskeletons are stained blue and green, respectively. By Omid Farokhzad and Robert Langer at MIT.

A key to the nanoparticles’ effectiveness is the ability of their RNA strands to bind to a cancer cell membrane. The cell then pulls the particles inside. Having the particles inside the cell has two advantages: it gets the drug where it needs to be to kill the cells, and it decreases the concentration of the drug outside the cancer cells, thereby decreasing toxicity to healthy tissue. The fact that the polymer releases the drug gradually also helps — the drug is released over the hours or days it takes for the particles to be pulled into cells, where it continues to be released, killing the cells.
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Eventually, the MIT-Harvard researchers hope to design nanoparticles that can be injected into the bloodstream, from which they could seek out cancer cells anywhere in the body, making it possible to treat late-stage metastasized cancer. “Even though this represents a small percentage of patients that actually have the disease, these are the ones that have no therapeutic option available to them,” Farokhzad says.

More life science related posts and medical related posts.