Feynman also suggested that it should be possible, in principle, to do chemical synthesis by mechanical manipulation.
He also presented the "weird possibility" of "swallowing the doctor," an idea which he credited in the essay to his friend and graduate student Albert Hibbs. This concept involved building a tiny, swallowable surgical robot by developing a set of one-quarter-scale manipulator hands slaved to the operator's hands to build one-quarter scale machine tools analogous to those found in any machine shop. This set of small tools would then be used by the small hands to build and operate ten sets of one-sixteenth-scale hands and tools, and so forth, culminating in perhaps a billion tiny factories to achieve massively parallel operations. This idea was anticipated in part, down to the microscale, by science fiction author Robert A. Heinlein in his 1940 short novel Waldo. As the sizes got smaller, we would have to redesign some tools because the relative strength of various forces would change. Gravity would become less important, surface tension would become more important, Van der Waals attraction would become important, etc. Feynman mentioned these scaling issues during his talk. Nobody has yet attempted to implement this thought experiment.
After his death, scholars studying the historical development of nanotechnology have concluded that Feynman's actual role in catalyzing nanotechnology research was limited based on recollections from many of the people active in the nascent field in the 1980s and 1990s. However, Feynman's stature as a Nobel laureate and as an iconic figure in 20th century science surely helped advocates of nanotechnology and provided a valuable intellectual link to the past.
Feynman was also known for his talks in low level science classes. He would ask to teach these classes, which would then be attended by graduate students, or even professors. His unique teaching style allowed him to take incredibly complicated subjects and transform them into a series of lectures that even his rudimentary physics students were capable of comprehending and applying.