Nanotechnology vs. Molecular Manufacturing

Nanotechnology is quickly becoming a reality for manufacturing new products that have improved performance characteristics and potentially new and innovative applications. However, there continue to be heated debates in the scientific community and increasingly in public forums on the direction of nanotechnology in the future and the potential benefits and threats. Today, nanotechnology actually has two primary meanings. The first meaning was described in the previous sections and addresses scientific and technological activities that take advantage of material properties at the nanoscale. Microchip manufacturing and consumer products fall under this first definition of nanotechnology. A second interpretation of nanotechnology is commonly referred to as ‘molecular manufacturing’ and involves the self-replicating molecular machines or nanobots that can build nanomaterials.

K. Eric Drexler is one of the most prominent advocates of the molecular manufacturing version of nanotechnology. The basic concept of molecular manufacturing was actually outlined by Richard Feynman in 1958. Feynman described a world where increasingly smaller machines could build at atomic precision (i.e. the bottom-up approach to nanomanufacturing). Drexler embraced this idea of manufacturing at the nanoscale and first published his ideas in a 1981 scientific journal article and later in his popular book, Engines of Creation (1986). Drexler’s vision of molecular manufacturing is inspired by molecular biology and involves the bottom-up construction of nanomaterials using assemblers. Assemblers are the crucial component to overcoming the costly and time-intensive nanomanufacturing. These micromachines or nanobots are theoretically capable of placing atoms in almost any arrangement. Furthermore, the assemblers would be self-replicating so they could build more assemblers that could speed up manufacturing processes dramatically. Drexler’s vision of molecular manufacturing is thought to be a long way off—he has estimated that the widespread use of assemblers to create nanoproducts is one to three decades away. But the promise of such a groundbreaking technological breakthrough has proven too enticing for many to stop contemplating. In theory, the molecular manufacturing would increase the amount of control in manufacturing process to the atomic scale and revolutionize manufacturing by making it cheap, fast, devoid of waste products, and highly energy conserving.

In addition to the benefits of molecular manufacturing, the idea of self-replicating nanobots may pose risks. Drexler was one of the first to address the potential downsides of molecular manufacturing in a chapter of Engines of Creation titled ‘Engines of Destruction’. Here, he imagined the possibility of nanobots developing out of control and the multiple impacts on society. Drexler likens the power of molecular manufacturing to the proliferation of chemical and biological weapons and advocates for careful and strictly regulated control of the technology. The potential dangers of self-replicating nanobots were further publicized by the chief scientist of Sun Microsystems, Bill Joy, when he published a 2001 article in Wired magazine contemplating the dangerous future of nano. Michael Crichton also created a story about imagined dangers of nanobots out of control in his bestselling 2003 science-fiction novel Prey.

The scientific community has generally downplayed Drexler’s notion of molecular manufacturing and instead focused on the more conventional definition of nanotechnology. Richard Smalley, a Nobel Prize winning chemist from Rice University, was one of the most outspoken critics of Drexler and molecular manufacturing. He argued that molecular manufacturing is a physical impossibility based on scientific principles. A particularly scathing exchange in the December 2003 issue of Chemical and Engineering News between Smalley and Drexler highlights the inherent scientific challenges in creating the assembler. Many nanotechnology researchers are worried that fears over the possible threats of nanotechnology fostered by Drexler, Joy, and others could derail the progress of nanotechnology and cause the public to reject nanotechnology.

In the mid-1990s, advocacy groups and scholars in North America and Europe began to raise concerns over the threats and unintended consequences of nanotechnology. The ETC Group, an activist organization that played a central role in the public opposition to genetically modified foods, has raised questions about issues of human health, social equity, and environmental destruction. In 2003, the group called for a global moratorium on nanotechnology research until guidelines could be developed on how to avoid the potential dangers and unintended consequences. The Foresight Institute, founded by Drexler, also issued guidelines for molecular manufacturing in 1999. And the international environmental organization Greenpeace issued a report on nanotechnology in 2003.

Further Reading:

• Baum, Rudy. 2003. Nanotechnology: Drexler and Smalley make the case for and against 'molecular assemblers', Chemical and Engineering News 81(48):37-42.
• Bennett, Ira, and Daniel Sarewitz. 2005. Too little, too late? Research policies on the societal implications of nanotechnology in the United States," unpublished manuscript.
• Drexler, K. Eric. 2001. Machine-phase nanotechnology, Scientific American 285(3):74-75.
• Peterson, Christine L. 2004. Nanotechnology: From Feynman to the grand challenge of molecular manufacturing, IEEE Technology and Society Magazine 23(4): 9-15.