Science & Technology:

Nanotubes and buckyballs and diamonds and life - carbon doing its thing...

From Wired News:

Nanotubes May Heal Broken Bones

By Aaron Dalton

02:00 AM Aug. 15, 2005 PT

Human bones can shatter in accidents, or they can disintegrate when ravaged by disease and time. But scientists may have a new weapon in the battle against forces that damage the human skeleton.

Carbon nanotubes, incredibly strong molecules just billionths of a meter wide, can function as scaffolds for bone regrowth, according to researchers led by Robert Haddon at the University of California at Riverside. They have found a way to create a stronger and safer frame than the artificial bone scaffolds currently in use.

Customized Y-shaped Carbon Nanotubes Can Compute

August 14, 2005 -- Researchers at UCSD and Clemson University have discovered that specially synthesized carbon nanotube structures exhibit electronic properties that are improved over conventional transistors used in computers. In a paper published* in the September issue of Nature Materials and released online on August 14, UCSD Mechanical and Aerospace Engineering professors Prabhakar Bandaru and Sungho Jin, graduate student Chiara Daraio, and Clemson physicist Apparao M. Rao reported that Y-shaped nanotubes behave as electronic switches similar to conventional MOS (metal oxide semiconductor) transistors, the workhorses of modern microprocessors, digital memory, and application-specific integrated circuits.

"This is the first time that a transistor-like structure has been fabricated using a branched carbon nanotube," said Bandaru. "This discovery represents a new way of thinking about nano-electronic devices, and I think people interested in creating functionality at the nanoscale will be inspired to explore the ramifications of these Y-junction elements in greater detail."

The stunning increase in the speed and power efficiency of electronics over the past two decades was primarily due to the steady shrinkage in size of conventional transistors. Chip makers have reduced the minimum feature size of transistors to about 100 nanometers, and that dimension is expected to shrink by the end of this decade. However, industry experts predict that fundamental technological and financial limits will prevent the makers of conventional MOS transistors to reduce their size much further. The Y-shaped nanotubes discussed in the Nature Materials paper are only a few tens of nanometers thick and can be made as thin as a few nanometers.

"The small size and dramatic switching behavior of these nanotubes makes them candidates for a new class of transistor," said Bandaru.

So, what is it that makes these nanotubes so special?

It's all about carbon.

For those who watched Star Trek (the original series, or even The Next Generation), likely you recall much discussion of "life as we know it" meaning "carbon-based life forms".

What exactly does that mean?

The fundamental chemistry behind life on Earth is based upon carbon.

There is an entire branch of Chemistry, called Organic Chemistry, that is devoted to molecules and reactions that involve carbon. This does not mean that all molecules that have carbon as a component are related to life, to the contrary, many if not most carbon-containing molecules are toxic or carcinogenic to most life.

However, almost all reactions related to life involve carbon as well.

Carbon is special because of its atomic structure.

Even though there are many other familiar names in the same column of the periodic table of the elements as carbon, such as silicon (the key material used to make the computer you are using to read this!), germanium (becoming more important in making high speed microprocessors), tin, and lead that all have similar chemical properties, none of these elements, nor any others, make the long chain molecules like carbon. There are some molecules based upon carbon that are as long as a millimeter!

Carbon also makes very strong bonds with itself. The hardest material known is diamond, which is a crystalline form of carbon. Strangely enough, one of the softer materials known, graphite (used in pencil lead, for those who still use pencils), is also made of carbon.

Nanotubes are made of carbon arranged in a structure that, naturally given the name, is a tube of carbon atoms. It is the strength of the carbon-carbon bond along with the long chaining that makes these molecules so special. A nanotube can be as long as a millimeter (perhaps even longer once we develop a method to fabricate them), and is very strong because of the carbon-carbon bonds.

Also, because of how carbon can make bonds with many other elements, the chemical and electrical characteristics of the nanotubes can be manipulated (within limits) to allow them to react with other chemicals in certain ways, or to behave under the influence of electric fields in certain ways.

In other words, carbon is unique in its chemical and electrical properties, and the molecular structures of nanotubes and buckyballs (more on that structure later) have many, many potential technological uses because the molecules can be manipulated more so than most other molecules known.

So, expect to see more news releases of how nanotubes and buckyballs are being applied to address different problems. This is the next technological revolution, and it may well have larger effects than even the microelectronic revolution of the last 15 years.

More on this topic later, if demand merits (in other words, if I get no comments or emails about this post, I won't follow up, if I get at least some interest, I'll spend the time and effort to write more... What, do you think it is easy to write about this stuff in non-scientific jargon???).

Technorati Tags: science, science & technology, science and technology, technology