Professor Zhao Hongwei publishe an article in IEEE/ASME Transactions on Mechatronics.

A piezoelectric actuator based on parasitic motion principle is proposed and tested. The piezoelectric actuator is explored to simultaneously realize coarse (long stroke) and fine (high accuracy) motions using dual-servo control method. The working principle of the proposed piezoelectric actuator is discussed, and finite-element method is adopted. A dynamic model of parasitic motion based on the LuGre friction model is simulated using matlab/Simulink. A prototype is manufactured to investigate working performance. Experimental results indicate that the maximum speed of the presented parasitic-type piezoelectric actuator is 7.95 mm/s and the resolution is 10 nm. These findings confirm the feasibility of the dual-servo nanopositioning system using piezoelectric stacks and flexure hinges.