An Auxiliary Friction Method for Miniaturizing the Inertial Impact Piezoelectric Actuators

The impact inertial piezoelectric actuators (IIPAs) are promising to be miniaturized as micro actuators due to their simple structure and high positioning resolution. In this work, a novel method is proposed to reduce the dependence on the inertial mass by exerting auxiliary friction on the inertial mass. To verify the validity of the method, a traditional IIPA (TIIPA) and an auxiliary friction IIPA (AFIIPA) are designed. The static analysis is conducted to determine their structural parameters. Then, their size and weight are identified as 9.6 mm×10 mm×7 mm and 0.8 g (the lightest IIPA to our knowledge), respectively. The dynamic analysis and experiments are performed, and the results demonstrate that under the same experimental conditions, the AFIIPA has lower sensitivity to inertial mass reduction and better output performances than those of the TIIPA. The maximum speed, output force, and resolution of the AFIIPA are improved by 81.8%, 67.2%, and 30.9% respectively, compared to the TIIPA. Besides, the AFIIPA has balanced comprehensive performances with extremely light weight compared with some previous micro actuators. This study provides a new miniaturization method for the IIPAs, which could advance the further development and applications of the micro IIPAs.