Taking Bearings

December 14, 2003

Anticipated by scientists — and widely heralded by science fiction writers — the nanotechnology genie may now be forever out of the bottle.

Nanotechnology deals with devices and components ranging in size between 0.1 to 100 nanometers. A nanometer is 10^-9meter, much smaller than conventional micro-technology based devices. One nanometer is one billionth of a meter. Operating far below the scale of micro-devices and below the scale of tools used to create and service them, nano-engineers utilize cutting edge tools such as atomic force microscopes to manipulate atoms or create fine surface layers with precision in design similar to creating electrical microcircuits.

Advancing beyond the simple nano-based sunscreen formulas and fibers, the nanotechnology industry is on a steady growth path. National Science Foundation estimates plot that growth into a trillion dollar market within a dozen years.

Researchers in the U.K. have recently developed nanoscale adhesives. And drug solubility experiments in the United States indicate that nanotechnology may be a vital link to the production of stable soluble compounds in formulas too unstable to prepare by conventional methods. At least two companies, Merck and American Home Products already market medical products, aprepitant (Emend), and, respectively, Rapamycin (Rapamune) that are based upon nanotenchnological processes (e.g., NanoSystems’ NanoCrystal® technology).

New generations of highly sensitive biosensors are also already in testing. Composed of carbon nanotubes that are stronger than steel and that have the capacity to function as components of electrical circuits (e.g., as conductors or semiconductors), nano-based sensors offer greatly enhanced sensitivity. Upon binding with specific molecules, changes in electrical resistance result in readable electrical signals.

Advanced testing is also underway that involves the use of nanotechnology to focus laser and drug treatments on target tumor tissues. Some nano-level drug-delivery schemes involve the use of buckyballs (buckminsterfullerene) that are hollow shells containing 60 carbon atoms arranged in a soccer-ball like geometric pattern.

Drugs made of nanotechnology-developed dendrimers (dendritic polymers) utilize structural features such as molecular layering and branching to interface with cell membranes, cell specific drugs, and compounds used to enhance diagnostic imaging.

Studies have shown that use such “smart” compounds diminish side effects and lower toxicity because they reduce the overall concentration of reactive compounds required without sacrificing drug efficacy.

A complete understanding of the inner workings and potential of nanotechnology requires an understanding of quantum physics because the laws of classical physics (e.g., classical mechanics) do not always apply to the atomic and near-atomic level. Quantum theory and quantum mechanics describe the relationships between energy and matter on the atomic and subatomic scale.  Many quantum concepts seemed counter-intuitive to well-established Newtonian physics and advancements associated with quantum mechanics (e.g., the uncertainty principle) have had a profound influence on both scientific and philosophical arguments regarding the limitations of human knowledge.

At the quantum level, the smoothness of classical physics disappears and engineering advances in nanotechnologies are predicated upon exploiting this quantum “roughness.”

At nano-levels, traditional engineering concepts undergo radical transformation. For example, nanotechnology-based motors (nanomotors) may drive gears, the cogs of which are composed by atoms attached to a carbon ring. Nanomotors may, in turn, be driven by oscillating magnetic fields or high precision oscillating lasers.

Defense programs in many countries are already concentrating on nanotechnology research programs as a means of improving smart weapons, stealth capabilities, and specialized sensors (including bio-inclusive sensors). In the United States, estimates peg expenditures on nanotechnology at more than $500 million per year — funding largely coordinated by the National Science Foundation and Department of Defense Advanced Research Projects Agency (DARPA) under the umbrella of the National Nanotechnology Initiative. Other institutions with dedicated funding to nanotechnology include the Department of Energy (DOE) and National Institutes of Health (NIH).

In addition to what experts argue are large sums tucked away into classified defense spending, U.S. and European governments are openly investing the equivalent of almost $4 billion U.S. dollars within the next three years to further accelerate the broader utilization of nanotechnology.

Although nano-sceptics remain, it seems likely that during the next decade the gap between nano-technology research and commercial utilization will narrow, especially in biotechnology. Engineers anticipate that advances in nanotechnology will allow the direct manipulation of biological molecules (e.g., proteins or nucleic acids). Potential nano-level manipulation of DNA offers the opportunity to greatly expand the horizons of genomic-based medicine and immunology. Tissue based nano-scale biosensors will be able to monitor and regulate site-specific medicine delivery and regulate physiological processes much more efficiently and unobtrusively than devices already on the market.

In electronics and computer science, scientists assert that nano-scale technologies will be the next major advance in computing and information processing science.

In the marketplace, barcodes layered with magnetic nano-particles will provide unalterable and nearly undetectable “watermarks” to deter fraud and theft.

There are, however, some caution signs along the road to the nano-world. Preliminary reports by toxicologists examining carbon nanotubes indicates a further study is needed to see if inhalation of the nanotubes produces granulomas similar to those associated with the inhalation of beryllium dust.

In some ways, nanotechnology is racing ahead of the ability to regulate the technology. In addition to the need to develop proper standards for risk assessment, scientists and philosophers are struggling to develop ethical standards.