Design, operation, and motion characteristics of a precise piezoelectric linear motor

This paper presents the design, operation, and motion characteristics of a precise piezoelectric motor for linear translation. The motor is compact, thermally stable, ultra-high vacuum compatible, and suitable for applications requiring fine resolution over millimeter-long travel ranges. Inside the motor, a translating alumina prism is symmetrically constrained within a stationary structure by a compliant suspension that preloads six shear-mode piezoelectric actuators against flat surfaces on the prism. A single step is achieved by sequentially sliding each piezoelectric actuator backward along the prism’s surfaces and then simultaneously moving all actuators forward. Many steps are repeated at 60 Hz for longer translations. Experiments indicate that: the step size is adjustable between 5 nm and 225 nm, the motor can reach speeds of 13.5 μm/s, the step size is highly uniform with a standard deviation of about 1.2 nm, error motion in the direction orthogonal to the translation is about 800 nm peak-to-valley, and the thermal stability is better than 40 nm/ °°C.