David Kirkpatrick

March 19, 2010

More news on laser-heated nanoparticles and cancer

Filed under: Science — Tags: , , , , , , , — David Kirkpatrick @ 12:53 am

There’s been a lot of blog-worthy news on cancer research and nanotech lately, particularly on heating nanoparticles with low-intensity lasers to zap cancer cells. I first blogged on this tech a couple of years ago, but lately a number of institutions have released different research results on the process so I’m guessing it is really getting somewhere. This amount of news release activity makes me wonder if this is getting close to actually treating people. This latest release — the third this month — is from the University of Florida. This particular laser-excited nanoparticle tech does go beyond medical usage

The release:

Engineers: Weak laser can ignite nanoparticles, with exciting possibilities

GAINESVILLE, Fla. — University of Florida engineering researchers have found they can ignite certain nanoparticles using a low-power laser, a development they say opens the door to a wave of new technologies in health care, computing and automotive design.

A paper about the research appears in this week’s advance online edition of Nature Nanotechnology.

Vijay Krishna, Nathanael Stevens, Ben Koopman and Brij Moudgil say they used lasers not much more intense than those found in laser pointers to light up, heat or ignite manufactured carbon molecules, known as fullerenes, whose soccer-ball-like shapes had been distorted in certain ways. They said the discovery suggests a score of important new applications for these so-called “functionalized fullerenes” molecules already being developed for a broad range of industries and commercial and medical products.

“The beauty of this is that it only requires a very low intensity laser,” said Moudgil, professor of materials science and engineering and director of the engineering college’s Particle Engineering Research Center, where the research was conducted.

The researchers used lasers with power in the range of 500 milliwatts. Though weak by laser standards, the researchers believe the lasers have enough energy to initiate the uncoiling or unraveling of the modified or functionalized fullerenes. That process, they believe, rapidly releases the energy stored when the molecules are formed into their unusual shapes, causing light, heat or burning under different conditions.

The Nature Nanotechnology paper says the researchers tested the technique in three possible applications.

In the first, they infused cancer cells in a laboratory with a variety of functionalized fullerenes known to be biologically safe called polyhydroxy fullerenes. They then used the laser to heat the fullerenes, destroying the cancer cells from within.

“It caused stress in the cells, and then after 10 seconds we just see the cells pop,” said Krishna, a postdoctoral associate in the Particle Engineering Research Center.

He said the finding suggests doctors could dose patients with the polyhdroxy fullerenes, identify the location of cancers, then treat them using low-power lasers, leaving other tissues unharmed. Another application would be to image the locations of tumors or other areas of interest in the body using the fullerenes’ capability to light up.

The paper also reports the researchers used fullerenes to ignite a small explosive charge. The weak laser contained far less energy than standard electrical explosive initiators, the researchers said, yet still ignited a type of functionalized fullerenes called carboxy fullerenes. That event in turn ignited comparatively powerful explosives used in traditional blasting caps.

Mining, tunneling or demolition crews currently run electrical lines to explosives, a time-consuming and expensive process for distant explosives. The experiment suggests crews could use blasting caps armed with the fullerenes and simply point a laser to set them off.

“Traditional bursting caps require a lot of energy to ignite — they use a hot tungsten filament,” said Nathanael Stevens, a postdoctoral associate in the Particle Engineering Research Center. “So, it is interesting that we can do it with just a low-powered laser.”

The researchers coated paper with polyhyroxy fullerenes, then used an ultrahigh resolution laser to write a miniature version of the letters “UF.” The demonstration suggests the technique could be used for many applications that require extremely minute, precise, lithography. Moudgil said the researchers had developed one promising application involving creating the intricate patterns on computer chips.

Although not discussed in the paper, other potential applications include infusing the fullerenes in gasoline, then igniting them with lasers rather than traditional sparkplugs in car engines, Moudgil said. Because the process is likely to burn more of the gasoline entering the cylinders, it could make cars more efficient and less polluting.

The researchers have identified more than a dozen potential applications and applied for several patents. This week’s Nature Nanotechnology paper is the first scientific publication on the discovery and the new technique.

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July 16, 2008

The Casimir force and nanotechnology

Filed under: Science, Technology — Tags: , , , , — David Kirkpatrick @ 12:54 am

I first blogged on the Casimir force, stiction and nanotech a couple of weeks ago (find that post here and check out the first item) Here’s some updated news out of the University of Florida. Physicists there have found a way to reduce quantum stickiness.

From the second link:

What seems like magic is known as the Casimir force, and it has been well-documented in experiments. The cause goes to the heart of quantum physics: Seemingly empty space is not actually empty but contains virtual particles associated with fluctuating electromagnetic fields. These particles push the plates from both the inside and the outside. However, only virtual particles of shorter wavelengths — in the quantum world, particles exist simultaneously as waves — can fit into the space between the plates, so that the outward pressure is slightly smaller than the inward pressure. The result is the plates are forced together.

Now, University of Florida physicistshave found they can reduce the Casimir force by altering the surface of the plates. The discovery could prove useful as tiny “microelectromechanical” systems — so-called MEMS devices that are already used in a wide array of consumer products — become so small they are affected by quantum forces.