While Smalley's contributions to nanotechnology were groundbreaking, his views were not without controversy. He engaged in a well-known debate with Eric Drexler, another pioneer in the field, over the feasibility and safety of molecular assemblers—machines capable of manipulating atoms and molecules to build complex structures. Smalley was skeptical of Drexler's vision of molecular assemblers, arguing that fundamental chemical and physical principles would limit their practicality. This debate highlighted differing perspectives within the scientific community regarding the potential and limitations of nanotechnology.
