Critics have doubted both the feasibility of self-replicating nanorobots and the feasibility of control if self-replicating nanorobots could be achieved: they cite the possibility of mutations removing any control and favoring reproduction of mutant pathogenic variations. Advocates address the first doubt by pointing out that the first macroscale autonomous machine replicator, made of Lego blocks, was built and operated experimentally in 2002. While there are sensory advantages present at the macroscale compared to the limited sensorium available at the nanoscale, proposals for positionally controlled nanoscale mechanosynthetic fabrication systems employ dead reckoning of tooltips combined with reliable reaction sequence design to ensure reliable results, hence a limited sensorium is no handicap; similar considerations apply to the positional assembly of small nanoparts. Advocates address the second doubt by arguing that bacteria are (of necessity) evolved to evolve, while nanorobot mutation could be actively prevented by common error-correcting techniques. Similar ideas are advocated in the Foresight Guidelines on Molecular Nanotechnology, and a map of the 137-dimensional replicator design space recently published by Freitas and Merkle provides numerous proposed methods by which replicators could, in principle, be safely controlled by good design.
critics have doubted both the feasibility of self-replicating nanorobots and the feasibility of control if self-replicating nanorobots could be achieved they cite the possibility of mutations removing any control and favoring reproduction of mutant pathogenic variations advocates address the first doubt by pointing out that the first macroscale autonomous machine replicator made of lego blocks was built and operated experimentally in 2002 while there are sensory advantages present at the macroscale compared to the limited sensorium available at the nanoscale proposals for positionally controlled nanoscale mechanosynthetic fabrication systems employ dead reckoning of tooltips combined with reliable reaction sequence design to ensure reliable results hence a limited sensorium is no handicap; similar considerations apply to the positional assembly of small nanoparts advocates address the second doubt by arguing that bacteria are (of necessity) evolved to evolve while nanorobot mutation could be actively prevented by common error-correcting techniques similar ideas are advocated in the foresight guidelines on molecular nanotechnology and a map of the 137-dimensional replicator design space recently published by freitas and merkle provides numerous proposed methods by which replicators could in principle be safely controlled by good design