View molecular manufacturing
Molecular manufacturing, or molecular nanotechnology (MNT), is the concept of engineering functional mechanical systems at the molecular scale. An equivalent definition would be “machines at the molecular scale designed and built atom-by-atom.” This is distinct from nanoscale materials. Based on Richard Feynman’s vision of miniature factories using nanomachines to build complex products (including additional nanomachines), this advanced form of nanotechnology would make use of positionally-controlled mechanosynthesis guided by molecular machine systems. MNT would involve combining physical principles demonstrated by chemistry, other nanotechnologies, and the molecular machinery of life with the systems engineering principles found in modern macroscale factories.
Smart materials and nanosensors
MNT could lead to the development of smart materials. These are materials designed and engineered at the nanometer scale to perform a specific task. There are many possible applications. One example would be materials designed to respond differently to various molecules; such a capability could lead, for example, to artificial drugs which would recognize and render inert specific viruses. Another is the idea of self-healing structures, which would repair small tears in a surface naturally in the same way as self-sealing tires or human skin.
MNT nanofacturing is popularly linked with the idea of swarms of coordinated nanoscale robots working together, a popularization of an early proposal by Eric Drexler in 1986 that has been superseded. In this early proposal, sufficiently capable nanorobots would construct more nanorobots in an artificial environment containing special molecular building blocks.
A fear exists that nanomechanical robots, if achieved, and if designed to self-replicate using naturally occurring materials (a difficult task), could consume the entire planet in their hunger for raw materials. Some commentators have referred to this situation as the “Gray goo” scenario. Drexler now considers an accidental “gray goo” scenario extremely unlikely.
Since 1992 technical proposals for MNT do not include self-replicating nanorobots, and recent ethical guidelines prohibit unconstrained self-replication.
MNT could create medical nanorobotics or nanomedicine. The ability to design, build, and deploy large numbers of medical nanorobots could make possible the rapid elimination of disease and the reliable and relatively painless recovery from physical trauma. Medical nanorobots might also allow the convenient correction of genetic defects, and significantly increase health and longevity. Medical nanorobots also have potential for human enhancement.
Potential social impacts and risks
Molecular nanotechnology could have daunting risks. It could enable cheaper and more destructive weapons. Also, molecular nanotechnology might permit weapons of mass destruction that could self-replicate, akin to viruses and cancer cells.
Much concern surrounds MNT’s anticipated impact on economics and on law. Some conjecture that MNT would elicit a strong public-opinion backlash, as has occurred recently around genetically modified plants and the prospect of human cloning. Whatever the exact effects, MNT, if achieved, it would tend to upset existing economic structures by reducing the scarcity of manufactured goods and making many more goods (such as food and health aids) manufacturable.
The Center for Responsible Nanotechnology