Developments of a piezoelectric actuator with nano-positioning ability operated in bending modes

This paper proposed a new piezoelectric actuator operating in two working modes: the resonance working mode under alternating current (AC) signals and the non-resonance working mode under direct current (DC) signals. The AC resonance working mode used the hybrid of two resonance bending vibrations to produce high speed and large stroke linear motion, whereas the DC non-resonance working mode used the static horizontal bending movements to achieve linear driving with micrometer stroke and nanometer resolution. The working mechanism of the actuator was illustrated; then finite element analysis (FEA) method was utilized to finish the design and analyses; at last a prototype was manufactured to measure the performance. Under the resonance working mode, the proposed actuator achieved maximum output speed of 1750 mm/s and the maximum output thrust of 30 N under 500 Vp-p. Also, when working under the DC non-resonance working mode, the maximum output displacement was 2.62 µm. And the measurable minimum output displacement was 50 nm, which can reach smaller in theory. The correlation coefficient between the output displacement and the input DC voltage is 0.998, which was good for the control of the actuator under the non-resonance working mode. This piezoelectric actuator can accomplish linear position quickly and accurately in a large stroke with simple structure using bending modes.