A New Stick-Slip Piezoelectric Actuator Using Dual-Arch Bridge-Type Compliant Mechanisms
Yuxi Wu, Yiling Yang, Gaohua Wu, Yuguo Cui, Yanding Wei
Abstract
This paper reports a new stick-slip piezoelectric linear actuator with large load density, compact size, and high resolution. It is devised using a dual-arch bridge-type driving mechanism (DBDM) and an integrated elliptical preload mechanism(IEPM). The DBDM can generate a coupling motion on the driving point, which provides clamping and releasing actions during stick-slip motion. Also, the DBDM can magnify the clamping force with large amplification ratios, thus improving driving force and load-carrying capacity. The IEPM uses compact flexure hinges to adjust preload force, reducing structural dimension. Then, theoretical analysis and simulations are conducted, and a prototype is fabricated. A modified driving voltage with smooth turning points is designed to improve motion properties further. Experiments show that load density is 0.037 g/mm<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathbf {3}}$ </tex-math></inline-formula> under the driving voltage of 100 V. The actuator has an overall size of 33.6 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 20$ </tex-math></inline-formula> mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 8$ </tex-math></inline-formula> mm and a displacement resolution of 22 nm.Note to Practitioners—Most research on linear actuators focused on motion displacement improvement, and more research needs to be done on improving load-carrying capacity. Therefore, this paper designs a force amplification linear actuator with a compact structure using the DBDM. In the experimental stage, the sudden change of the driving signal affects the output performance, and a modified sawtooth voltage is used to improve the output speed and load-carrying capacity. The experimental results show that under the modified sawtooth wave voltage, the maximum speed of the slider is 1.4 mm/s, and the speed is increased by 17% compared with the traditional wave. When a 200 g load is applied to the slider, the linear actuator operates at a stable speed of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.2~\mu $ </tex-math></inline-formula>m/s, 33% faster than conventional sawtooth waves. As a result, the designed actuator has superior performance at higher loads.