Thursday, January 1, 2009

Nano Today Cover Competition

Spiraling pine tree-like PbS nanowires are evidence of nanowire growth driven by screw dislocations without the help of metal catalysts. Screw dislocation drives the rapid growth of the nanowire tree trunk and causes the lattice of the trunks to twist (called "Eshelby Twist") and their epitaxial branches to spiral. See Science 2008, 320, 1060.Matthew J. Bierman, University of Wisconsin-Madison, USA

In the Blink of an Eye

Drexler's original definition of nanotechnology was "the ability to
construct shapes, devices and machines with atomic precision and to
combine them into a wide range of products inexpensively." Since then,
however, nanotechnology has come quite a ways from this purely
theoretical understanding, according to Rocky Rawstern, editor of
Nanotechnology Now.

Says Rawstern, "I have seen Mercedes-Benz using nanoparticle paint
that helps prevent wear and other companies make [nanotech] golf balls
that reduce slice, nanopowder aluminum for better rockets, stainless-
steel metal for injection-molding, nanosilver particles for anti-
bacterial and disinfectant agents, fullerenes (nanoparticles of
tungsten disulfide) as lubricants, and the list goes on."

According to Rawstern, there are several contemporary definitions of
nanotechnology, of which at least three were "created by different
groups, each with their own agenda."

"Nanotechnology has evolved via a terminology drift and purposeful
misapplication to mean anything smaller than microtechnology," says
Rawstern, "but without referring to mechanisms that have been
purposefully built from nanoscale components, as was originally
intended. This 'evolved' version of the term is more properly
labeled "nanoscale bulk technology,' while the original meaning is now
labeled "molecular nanotechnology' or 'molecular manufacturing (MM).'"

In addition to Drexler's theoretical definition is a working format is
maintained by the National Nanotechnology Initiative, a federal
research and development program established to coordinate nanoscale
science, engineering and technology, which includes:
  • development of research and technology at the atomic, molecular or macromolecular levels, in the length scale of approximately 1 nm to 100 nm range
  • creation and use of structures, devices and systems that have novel properties and functions because of their small and/or intermediate size
  • ability to control or manipulate on the atomic scale
According to Rawstern, the third definition comes from "the nano-
charlatans of the world, who have hijacked the term and are using it
to promote products that are neither nanoscale mechanisms nor
nanoscale materials" by any industry definition.

"Read the news most any day and you will find one or more nano-posers
promoting their wares, none of which are "nanotechnology' in any
meaningful sense of the term," he says. "Their definition: anything we
can slap the label nanotechnology on and get away with."

Inner Space

If Rawstern sounds a little irked, it's not because the field of
nanotechnology is expanding at an exponential rate (some analysts
predict the nanomaterials market will reach $1.4 billion in 2008);
rather, the financial and resource investment necessary to adequately
fund successful nanotech research is too great to squander on

Yet for all this hype, Rawstern says, this technology remains on the
drawing board, not purposefully pursued by any known entity, but
promoted by several. "It has yet to be proven, primarily because there
has been no substantial investment in developing a proof of concept,"
he adds.

What's To Come

The intermarriage of nanotechnology and imaging promises to be a long and prosperous one, with glimpses of additional advances, from imaging to interventional techniques, coming as fast as research allows. Sitharaman, for one, hopes his work will lead to cellular-level diagnosis of treatment efficacy and possibly even spur development of future medicine delivery systems.

"The rational leap of this technology should be to attach antibodies and peptides to these contrast agents to treat diseases," says Sitharaman. "You can attach different kinds of molecules to the fullerene for a more specific sequencing approach. Since they show such high relaxivity rates, we should hopefully be able to look at individual cells."

Of a similar mind is Rawstern, who also believes nanotechnology will expand its presence into the field of drug delivery systems, aided by imaging advances.

"In the next five years, I expect to see human trials on gold nanoshells come to a conclusion regarding their viability," says Rawstern. "They represent a potential end to the scourge of many cancers and an end to the suffering of thousands, if not millions, in the coming decade. Nanosuspension technology, which makes poorly soluble drugs with increased absorption rates, also looks promising. There are many more possibilities; more than anyone would have guessed only 10 years ago."

"No informed person doubts that developments at the nanoscale will be significant," says Rawstern. "We debate the time-frame, the magnitude and the possibilities, but not the likelihood for large-scale change. The least-speculative views suggest that we're in for changes of an order that justifies – if not demands – our undivided attention. Will we be ready?"

Tomorrow's Kitchen & Bath

Nanotechnology is another major force that will change the shape of
things to come in kitchens and baths. "In the near term, we’ll see
lighter materials, improved energy efficiency in lighting, and energy
storage devices for those who find themselves off the grid or wish to
employ backup devices,” reports Rocky Rawstern, Editor of
Nanotechnology Now.

Over the next few years, lightweight insulation will reshape kitchen
appliances, and organic light-emitting diodes will be widely used.
Within a decade or more, Rawstern claims, most surfaces will be coated
with antibacterial materials, thereby making disinfecting kitchens and
baths a thing of the past.

According to Rawstern, we’ll also enjoy a host of new materials that are lighter, stronger, and have properties we can only imagine, such as self-cleaning surfaces and embedded sensors.

The Twinkie Guide to Nanotechnology

This is the most well reasoned presentation on current and future nanotechnologies that I have seen. Well worth the time to view and consider, and should be mandatory viewing for all stakeholders (that’s you and I and everybody).

Dr. Andrew Maynard is Chief Science Advisor to the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars.

Dr. Maynard's bio: