What term refers to extremely tiny robots?

The term that refers to extremely tiny robots is nanorobots. These are engineered at the nanoscale, typically measuring between 1 to 100 nanometers in size. Nanorobots have the potential to revolutionize fields such as medicine, where they can be used for targeted drug delivery, diagnostics, and even cellular repair. Their small size allows them to operate at the molecular or cellular level, making them uniquely suited for intricate tasks that larger robots cannot perform.

While micromachines and microbots refer to robots that are still small but on a larger scale compared to nanorobots, they do not capture the full essence of what nanorobots can do due to their more significant size limitations. Quasi-robots is not a standard term recognized in robotics or nanotechnology and does not relate to the specific context of extremely tiny robots. Therefore, nanorobots is indeed the most accurate term among the options provided.