A Self-Sensing Piezoelectric Traveling-Wave Microactuator

Piezoelectric traveling-wave microactuator based on microelectromechanical systems (MEMSs) technology has the advantages of miniaturization and easy to integrate. However, the lack of angle sensing function limits their application in the aspect of microstructural rotation closed-loop control. Here, we present a self-sensing piezoelectric traveling-wave microactuator. By integrating the capacitive encoder with the microactuator, high-precision step angle rotation can be achieved, facilitating rotation closed-loop control of various MEMS microstructures. The prototype size of the self-sensing microactuator is
$5 \times 5$
mm. The angle detection accuracy and the resolution can reach up to 0.06° and 0.01°, respectively, which ensures the microacutor complete adaptive angle adjustments. This work is expected to pave a new way for in situ calibration of inertial sensors, microrobot movement, control of optical devices, and light path manipulation.