Design and Modeling of a Novel Wheel-Type Piezoelectric Nanopositioning Motor with Centimeter-scale Stroke

In order to solve the conflict between high precision and large stroke in the micro/nano operation field, this paper presents the development of a flexure-based wheel-type motor (WTM) driven by piezoelectric(PZT) actuators, which can generate end-effector motion in the range of over 30cm and with subnanometer resolution. In nano-positioning, the short stroke of the PZT actuator limits the process of development and application. The conventional lever displacement amplification mechanism cannot fully fix the requirements of practical applications. The structure designed in this paper, wheel drive structure (WDS), which has relative small size. The devise of WDS converses intermittent stroke into the wheels rotation, which is finally shown as continuous linear output. Especially, the WTM is composed of asymmetric hinges, which produces an arc motion through parasitic displacement. With the character of the structure, there is no limit to the stroke of the output theoretically. After mechanical optimization design, the matrix-based compliance modeling (MCM) method is adopted for static modeling, dynamic modeling and transient modeling of the device. Finally, the reason by finite element analysis (FEA) method is satisfied to inspect the performance of WIM.