Popularizing Nanoscience: Introduction to nanoscience


Summary

The term nanoscience is typically used to identify pure research at the molecular level. This work endeavors to identify the unique physical properties and characteristics of matter at the scale of one-billionth of a meter (a human hair is approximately 80,000 nanometers). Nanotechnology is the application of these principles and structures typically in the creation ofnanoscale devices.

At the nanoscale, accepted states and properties of matter encounter what Ratner and Ratner (2003) call the more “exotic” properties of the atomic and molecular world including wave-particle dualities and quantum effects. Because of the unique conditions of matter at the nanoscale, the field has emerged almost simultaneously in physics, chemistry, electronics, and biology. Potential nanotechnology applications have included the pursuit of molecular-sized computer memory, pharmaceutical and medical applications, pollution detection and clean-up, and textile manufacturing. As a research area, the field has been relatively quick to stabilize. Nanoscale science and technology has been targeted as a federal research and development priority. In 2003, $679 million was budgeted in federal support for the field. This is after $422 million were spent on the field in 2001 and approximately $600 million in 2002 (Ratner and Ratner, p. 2).

There's plenty of room at the bottom: A tiny history of nanotechnology

The term, “nanotechnology” was coined by K. Eric Drexler, an early proponent of molecular manufacturing. Drexler introduced the term and the concept while a student at MIT. Drexler's concept was informed by a 1959 speech titledThere's plenty of room at the bottom given by Nobel Prize-winning physicist Richard Feynman. Feynman speculated that in the future, scientists would be able to arrange atoms into any substance desired. Drexler took this concept and applied it to a variety of different fields claiming that molecular-sized machines could repair damaged cells, create endless amounts of fuel, structure microscopic computers, and even provide the technology for cyronics, the hope of bringing dead cells back to life (Trausch, 1988). This vision was the conceptual foundation of Drexler's 1986 book Engines of creation: The coming era of nanotechnology. Engines was a popularized account of Drexler's vision and was embraced by many fringe science fiction and fantasy groups. Drexler's more complex Nanosystems: Molecular machinery, manufacturing, and computation presented the scientific case for molecular manufacturing. The book was not well received in scientific communities. Critics argued that the concept of molecular manufacturing was a fundamental misunderstanding of chemistry. Others noted that nothing in the book had been demonstrated or replicated (Regis, 2004).

While Drexler's vision of nanotechnology started at the molecular level, others working in the field started with larger chunks of matter which they then broke down to nanosized particles. This approach was enabled by new technologies such as the scanning tunneling microscope, introduced by Gerd Binning and Heinrich Rohrer at IBM's Zurich Research Laboratory in 1980 and the atomic force microscope invented in 1985 by Binning. These technologies enabled scientists to obtain three dimensional images at the nanoscale from metal surfaces. Such images are useful for determining the size, arrangement, and connections among the molecules and aggregates on the surface of the metal. In 1985, Richard Smalley and Robert Curl at Rice University and Sir Harry Kroto, from the University of Sussex, discovered a new form of carbon which they called a "buckyball" as its structure mirrored the domes created by inventor Richard Buckminster Fuller.

Smalley was a strong critic of Drexler's vision of nanotechnology and of the concept of molecular manufacturing. In 2001, in an article in Scientific American Smalley contested the basic premise of molecular manufacturing claiming that Drexler's ideas were not possible. Smalley wrote, “ Selfreplicating, mechanical nanobots are simply not possible in our world. To put every atom in its place--the vision articulated by some nanotechnologists-would require magic fingers. Such a nanobot will never become more than a futurist's daydream (Smalley, p. 77). Although Eric Drexler's vision did much to popularize the field, by the year 2000 Smalley's carbon Buckyballs had become the image and principle marketing tool of the nano-industry.

Throughout the late 1980's and 1990's discoveries and new measuring technologies encouraged further interest and progress in top-down approaches to nanoscale research. In 1988, AT&T Bell Labs chemists Paul Alivisatos, Moungi Bawendi, and Michael Steigerwald showed that molecules behave differently at the atomic level. This work empirically tested claims which had been theorized by quantum mechanics. Other projects, including the formation of the IBM logo out of xenon atoms (by IBM scientist Don Eigler in 1990), and the creation of a 10 micrometers sized guitar (at Cornell in 1997) demonstrated the potential for exact manipulation of atoms at the molecular scale. The industrial applications of nanotech were improved following the discovery of carbon "nanotubes," which were Buckyballs linked and shaped into hollow carbon tubes. Nanotubes showed researchers that molecules could be shaped in different ways at the nanoscale.

Predictions about nanotechnology have been broad ranging and fantastic. Articles in the public media have claimed that nanotechnology will lead to cryogenics and the repair of damaged (or dead) cells (Drexler, 1986, p. 135), a cure for cancer, self-repairing highways, bullet-proof clothing as thin as a rain jacket (Berger, 2003), and affordable, abundant, energy (Economist, 2003). Although not a prominent part of the literature, cautions about nanotechnology have been raised as early as Hapgood's 1986 article in Omni Magazine (Hapgood, 1986) which was one of the first popular accounts of nanotech research. Those cautious about building molecular sized machines have coined the term "grey goo" to refer to intelligent swarms of Nano robots the size of a virus that devour everything in their path (Radford, 2003). This nano-terror was the plot of Michael Crichton's novel Prey released in November 2002. Other writers have claimed that nanosized particles, because of their size and ability to seep into skin and vital organs, may be toxic to humans (Feder, 2003). In April 2003, The Manitoba-based ETC group became the first advocacy group calling for a moratorium on the manufacture of synthetic nano-particles created in the absence of health, safety, and environmental impacts (ETC group web site. http://www.etcgroup.org/).

Despite these wide ranging claims, the initial applications of nanotechnology have been rare and selective. In some cases, existing technologies have been problematically re-situated as nanotechnology. Nanotechnology has been applied in electronic computer memory technology and in polymer coatings. Because of their high conductivity and strength, carbon nanotubes are useful for making computer chips and memory storage devices. However, these applications are not novel and have been in place for several decades. For example, much of the work in nanoscale electronic memory storage intersects with what is called MEMS (or MOEMS) Technology, or micro (optical)-electrical-mechanical systems, which apply molecular layers onto silicon to integrate mechanical elements, sensors, and other electronics. In polymers, molecular sized particles have been blended and layered on surfaces since the 1960s. More recent uses of nanotechnology have occurred in automobile manufacturing to create stronger materials, textile manufacturing to increase stain resistance, and in various beauty products such as skin cream and suntan lotions (Hearn, 2003).

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