Rotary-Linear Piezoelectric Microactuator With a Cubic Stator of Side Length 3.5 mm

We report a miniature rotary-linear piezoelectric actuator with a single cubic stator of side length 3.5 mm which can generate rotary motion around the center axis and linear motion in the axial direction. The stator is fabricated as a single metallic cube of side length 3.5 mm with a 2.5-mm-diameter through-hole and four piezoelectric elements bonded to the sides of the stator. The simplicity makes the actuator compact without any special manufacturing. In the design for miniaturization, the modal analysis using the finite element method indicates the natural frequency of the stator from the side length 14 mm to 3.5 mm. In the experiments, rotary motion of 24 rad/s and 2.5 mu Nm were obtained at a resonant frequency of 280 kHz, and linear motion of 80 mm/s and 2.6 mN was observed at 305 kHz by driving the system at an applied voltage of 42 V-rms.