*3.3.5 Piezoelectric motors*

One advantage of using piezoelectric materials is that their characteristics are precise and predictable. Thus, expansion and contraction of a piezoelectric actuator can be precisely controlled as long as the supply voltage is controlled. Some motor designs take advantage of this fact by using piezoelectric elements to move a rotor or linear element in precise increments. Precision on the order of nanometers can be achieved with some piezo motor designs. Piezo motors work at a wide range of frequencies but typically work best in a low frequency range.

In addition to their inherent precision, piezoelectric motors can be used in environments with strong magnetic fields or cryogenic temperature — environments where conventional motors are unlikely to work. These unique challenges are present in MRI machines, particle accelerators, and other similar environments.
