An inchworm motor is a cooperative linear actuator system in which multiple elements (originally piezoelectric, later often electrostatic) are activated in a coordinated sequence of step-wise motions, enabling extended motion range relative to individual actuators and high-precision positioning.
thumb|250px|Figure 1. Diagram of piezo inchworm motor in action.
History
Inchworm motors originated in the 1960s as multi-actuator mechanisms for high-precision positioning. Driven by advances in micromachining and microfabrication, designs shifted in the 1990s toward electrostatic microactuators, employing coordinated step sequences to achieve precise, linear motion beyond the limits of single actuator elements.