Nanotechnology: Do You Know What It Is? Do You Care?

August 24, 2009

No. Nanotechnology is not what makes iPod's Nano possible. If only it were that simple. But it really begs the question, Do you know what nanotech is? And for those of you who have a pretty good idea, Do you care?

The reason I ask is that lately I've been noticing a flutter of announcements, commentaries, and news pieces about whether nanotechnology is safe or not. For example, last fall, Andrew Maynard, chief scientist at Project on Emerging Nanotechnologies, testified before the U.S. Congress’s House Science Committee, saying that the government is not doing enough to ensure the safety of these materials.

Hotel California for Bacteria

November 26, 2008

You know how the Eagles song goes: "You can check out any time you like, but you can never leave." Now scientists have developed a similar hotel California for bacteria, only this one is molecular in size (and no stabbing of steely knives).

Kurt Schanze and his team from the Universities of Florida and New Mexico have created microscopic spheres that ensnare bacteria and kill it.

The scientists designed the spheres from polymers that, when exposed to light, produce a form of oxygen that kills bacteria, similar to how bleach kills it. They tested it on a close, but harmless relative of Pseudomonas aeruginosa, a common and lethal bacteria found in hospitals. When exposed to one hour of light, 95 percent of the harmless relative, Pseudomonas aeruginosa PAO1, died. Further testing should determine whether it kills the harmful strain and others like it.

The idea is that the polymer spheres could be used in coatings that are applied to doorknobs, medical devices or other surfaces where diseases often breed.

Photo: Wonderlust Industries

Tiny Backpacks Carry Cancer Drugs

November 07, 2008

Backpack carriers keep get smaller and smaller. Today, it's Kindegarten children. Tomorrow, biological cells. Scientists at the Massachusetts Institute of Technology have figured out a way to attach a little polymer package to two different kinds of immune cells.

Think about it: immune cells naturally zero in on disease and infection. If you could get the cell to carry a drug or some other item that helps doctors diagnose or treat disease, you could go a long way toward curbing or curing those diseases.

The package is made of three parts: a bottom layer designed to attach to the surface of the cell, a middle part that accommodates a payload and a top section designed to attach to other cells, such as cancer cells.

The polymer backpack has a lot of functionality. For example, by filling the middle part with magnetic nanoparticles, Michael Rubner, director of MIT's Center for Materials Science and Engineering, and his team found that they can control a cell's movement using an external magnetic field. The backpack could carry imaging agents that help identify tumors and it could also be filled with chemotherapy agents designed to target tumor cells.

Rubner and his team are reporting their work in the Nov 5 issue of Nano Letters.

Image courtesy American Chemical Society

Nano Has Flower Power

September 24, 2008

Cell phones, iPods and other electronic device need battery power. And if you own any of these, you know firsthand how quickly those batteries wear down. I got my cell phone plugged in right now and know that even if I leave it tethered to the socket for infinity plus one, I'll still see the battery bar depleted by the end of the day tomorrow.

Scientists own cell phones, too. And they get just as irked. Some of them, like Hao Zhang at the Research Institute of Chemical Defense and his colleagues at Peking University, are working on a solution:  nanoflower/carbon nanotube composite electrodes. They report their work in ACS' Nano Letters.

The researchers grew nano-sized flowers (right) made from manganese oxide, a metallic material already used in batteries. According to Zhang (I emailed him in China and asked), the flower shape has several powerful advantages.

First, each manganese oxide nanoflower is connected directly with the current collector (below) by two or more electron "stems" made from carbon nanotubes. Carbon nanotubes are strong, so they offer good mechanical support, and they are excellent for shuttling electrons. As a result, this shape "allows for efficient charge transport and enhances the electronic conductivity of composite significantly," said Zhang.

Second, the small nanometer size means the charged particles (ions) don't have to travel very far, which  ensure that their charge is fully utilized and very little goes to waste.

Third, micropores in the flower offer low resistance to the ions.

Fourth, because every manganese oxide flower is connected to the conducting framework, the need for binders or conducting additives, which add extra contact resistance or weight, is eliminated.

Images: Courtesy Hao Zhang

Seventeen Going on Gates

September 18, 2008

So on the last day of the nano-bio conference in Madison, the attendees heard a talk given by Philip Streich, winner of the 2007 Intel Young Scientist Award.

Phil is 17 -- was 16 when he won the award -- and has since co-founded a company in Wisconsin called Graphene Solutions based on his discovery. The discovery? Well, it has to do with carbon nanotubes. These tiny little molecules are super strong and conductive. (See my post from yesterday.) But they also like to clump together and when they are all clumped together, they are about as strong and conductive as a plate full of spaghetti.

Scientists have been trying for some time to get the carbon nanotubes to unclump. But haven't been able. So along comes this teenager and he figures out a way to do it. The solution to the problem is, in fact, a solution in the liquid form. The result is....well...imagine all of that spaghetti mixed into a large bowl of jello before it has solidified. The noodles unclump from each other. Then at some point the jello hardens. And you have a solid layer of material containing noodles that are not sticking to each other.

That's what Phil did. Except instead of noodles, he used carbon nanotubes. And instead of jello, he used a polymer (thin layer of plastic).

His presentation was over my head in terms of the science and math. But the message for me was pretty clear: he found a way to do it and he's only 17. In another 10 years or so, he'll probably be running a large corporation ala Microsoft.

Photo: Intel

Hello From Madison, WI

September 14, 2008

For the first part of this week, I'm in Madison, WI (right), attending a nanotech conference specially designed for reporters. The conference, "Nano Meets Bio: The Risks and Rewards," is off to good start. I wasn't sure what to expect really. I've been to a lot of conferences in my day and they can sometimes be too sciency (read: booooring!) But the first talk, by Wendy Crone, associate professor in the dept of engineering, was anything but.

Crone spent her time getting us all familiar with the concept of nanotechnology. We humans are pretty dense about stuff we can't see. Out of sight, out of mind, don't cha know. So she had us do a little activity to put nanotech into perspective. She gave us all strips of paper about the length of a pencil and safety scissors (there was wine drinking, after all). She asked us to cut that strip in half, then cut that half in another half, then cut that half in half, etc., etc., and to see how far we could get. I could only do it 7 times. Granted I don't have the most delicate lotus-petal-like fingers in the world nor was I using the most advanced cutting technology. But the point became quickly tangible. I couldn't get that far and even though my mere spec of a paper was just that, mere, I would need another 20 snips or so for it to count as nano-sized.

Try it, if you don't believe me.

She made a lot of great points, namely that nano is small, and when things get down that small, they sometimes behave in ways that they don't on a larger scale. It's like the particles are on Las Vegas time or something. They become very volatile or change color or get drunk and blow all of their cab fare on the nickel slots.

Crone also pointed to a great graph (right) that originated in a 2001 report from Merrill Lynch, called "The Next Small Thing: An Introduction to Nanotechnology." It makes the point that, basically, nanotech is an innovation on par with the car and the computer. Today, the technology is new, we don't know too much about it, what it can do, how it will help or hurt us, the possibilities it will open up. In fifty years, it will be everywhere and like the hundreds of computers that surround us, we may not even think twice about its existence.

Photo: Jeff Miller, UW-Madison University Communications

Nanotech Pain Kills Bugs

September 10, 2008

A funny thing happens when you add titanium dioxide to paint and then hit it with fluorescent light: bacteria die. Well, okay. Not so funny for bacteria. But it could be an effective way to destroy superbugs in hospitals, public and commercial facilities, schools and residential kitchens, baths and floors would be significant . Think about it. Just add titanium dioxide -- the white compound that makes the "M" on M&M candies -- to paint, put it on the walls and then turn on the lights.

In lab tests, Lucia Caballero from Manchester Metropolitan University, found that the food poisoning bacterium Escherichia coli was killed under normal, fluorescent light. Here's why: When the titanium dioxide absorbs energy from the light, a chemical reaction occurs that results in two molecules, hydroxyl radicals and superoxide anions. Both work to decompose  microorganisms by causing cell rupture and leakage of vital composition.

With rising concern about the spread of hospital superbugs, this new kind of paint could be one cost-effective way to healthcare maintain hygienic standards.

Photo: AP Photo/Jeff Christensen

Church Window Purifies Air

August 27, 2008

Here's a strange little tidbit. Scientists at Queensland University of Technology have found that stained glass windows common in medieval churches helped purify the congregational air -- and I'm not talking spiritually.

Window glaziers used gold particles in the paint. When sunlight shines on the window, the electromagnetic field of the protons couples with the electrons in the gold particles and creates a resonance. That breaks apart airborne pollutants, such as methanol, carbon monoxide and those volatile organic molecules from new furniture, carpets and paint.

The scientist, associate professor Zhu Huai Yong (right), calls the stained glass windows "photocatalytic air purifiers with nanostructured gold catalyst." I think you could buy the windows at Ye Olde Nano Shoppe.

Photo: Queensland University of Technology

Online Inventory of Nanotech-Based Consumer Products

August 25, 2008

Although nanotech seems like one of those future areas that won't be realized for years, consumer products based on this area of research are already entering the marketplace. You can find nanosized materials in electronics, automotive, medical and cosmetic products. But what are they?

The Project on Emerging Nanotechnology has published the first public, online inventory designed to help answer that question. While not comprehensive, this inventory lists more than 500 nanotechnology-based consumer items for sale. PEN is keeping a running list (and making it available to you) because they don't feel entirely confident that researchers and policymakers understand how nanosized materials may affect the environment or the people that come into contact with the materials (either in the factory or on the store shelf).

The categories are:

• Appliances
• Automotive
• Coatings
• Electronics
• Food and Beverages (REALLY??)
• Goods for Children
• Health and Fitness
• Home and Garden

Take a look to see if any products you have around the house contain nanosized materials.

Photo: Getty Images

A Balloon Just One Atom Thick

August 12, 2008

You hear a lot these days about carbon nanotubes. But lately there's been even more buzz about nanotubes' cousing, graphene -- a layer of graphite just one atom thick. It's chemically stable and electrically conducting, two characteristics that make it (and carbon nanotubes) appealing for use in future electronics.

This week, researchers report an interesting use for graphene: an atomic membrane that is impermeable to gas molecules and can be easily incorporated into other devices.

The researchers from Cornell are calling their membrane the world's thinnest balloon and are saying that it could have a range of applications from hyper-sensitive pressure, light and chemical sensors to filters able to produce ultrapure solutions. They report their work in the August 13 issue of ACS' Nano Letters.

Photo: American Chemical Society