Problems and Dangers Associated with Nanotechnology

To become feasible, nanotechnology must overcome many technical problems. These problems concern interacting nanoscale objects with complex chemical bonding forces and quantum mechanics in a nanoscale environment (Ashley, 2001). The major problem is associated with the construction of the assembler. As mentioned earlier, the assembler would have a moving arm which would pick up an atom and insert it in the desired place. To be able to do that, this moving arm should be smaller than the atom. But atoms are already the smallest building blocks from which the arm’s jaws can be built (Whitesides, 2001). Another obstacle lies in the nature of atoms, their tendency to bond strongly to their neighbors. The atom which is to be moved will adhere to the assembler’s arm. So it will be very difficult to release this atom in precisely the right spot (Smalley, 2001).

The effectiveness of the assembler in placing atoms in the desired place would be perhaps up to a billion new atoms per second. Although this rate seems very fast, in the macroscopic world it would be virtually useless. To produce 30 grams or about one ounce would require at least 6 x 1023 bonds, one for each atom. At the rate of 109 per second it would take this assembler 19 million years (Smalley, 2001). To be of any practical use, this molecular machine must be able to make another copy of itself, i.e. to self-replicate, much as biological cells do (Drexler, 1986; Ashley, 2001; Smalley, 2001; Whitesides, 2001). The process of self-replication of one assembler would take approximately one thousand seconds. So, at the end of ten hours there would be over 68 billion copies of new replicators. In less than a day they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined, if the materials needed to make new copies have not been depleted before (Drexler, 1986). This scenario has raised the prospect of what has come to be called grey goo: billions of tiny nanorobots replicating uncontrollably, consuming everything in their path (Stix, 2001; Whitesides, 2001). So far, we do not even know how to build a self-replicating machine of any size or type (Whitesides, 2001).

Environmentalists fear that nanotechnology may create contaminants whose tiny size makes them very hazardous. For example, nanoparticles are not dangerous themselves but with contact with other particles which are hazardous they also may become harmful. Many nanoparticles serve as bloodstream carriers that attack many dangerous diseases, e.g. cancer. They also could carry hazardous toxins (Krane, 2002). Some researchers speculate that carbon nanotube molecules which are used in production of electronic parts may cause cancer the way asbestos fibers do (Krane, 2002).

Huge nanotechnological potential can also be used to extend today’s weapon capabilities by miniaturizing guns, explosives and electronics components of missiles. Disassemblers could attack physical structures or even biological organisms at the molecular level. Moreover, this technology would find many applications in electronic surveillance, where molecular size microphones, cameras and homing beacons could monitor and track other people (Chen, 2003).