On IDE Piezoelectric Actuator And Its Applications In Bionic Wing

Piezoelectric actuators had been used widely in the intelligent materials & structures. However, some disadvantages, especially the low induced displacement and isotropic laminate layers, deeply limit their applications requiring off-axis or twisting motions. They should be researched further for adapting to the development of the intelligent materials & structures.IDE(Interdigitated Electrodes) actuators are denominated by electrical connections configuration which are made through a separate Interdigitated Electrode (IDE) layer having alternating finger-to-finger polarity. The Interdigitated Electrodes effectively align the electric field and polarization with the long axis of the piezoelectric actuators, enabling the use of the primary piezoelectric effect: longitudinal length extension vibration mode and piezoelectric strain constant d33, to enhance the directionality of the electromechanical response. IDE actuators are suit for the flapping wing by the advantageous features, namely, directional actuation and high strain energy density.Flapping wing is a complicated intelligent robot with new locomotion method, which would find its extensive application for military and civilian purpose. IDE actuators and flapping wing are researched in the paper. The major contributions and original researches in the dissertation are summarized as follows.1. A series of piezoelectric unit's equations about longitudinal length extension vibration mode are established. According to the dynamic FEM(finite element method) equations for piezoelectric actuator, which are established by means of Lagrange function and Hamilton principle, a series of finite models are established.2. The performance of mechanics and electrics is analyzed in detail. FEM is employed to numerically research the influence of composite materials and dimensions of each phase on the AFCs/MFC actuator's induced strain, stress and electrostatic field. The distribution of stain, stress and electrostatic field inside the AFCs/MFC structures is given by FEM. Then the optimization is presented. Response of the IDE piezoelectric ceramics actuator is predicted through the advancement of Uniform Fields and FEM. These models predict the mechanical and electrical properties effectively. Several rules are summed.3. IDE piezoelectric ceramics actuators are made from PZT-51. Harmonic analysis of IDE piezoelectric ceramics actuators are made using the software ANSYS in detail. In addition, resonance frequency is extracted using impedance analysis instrument. To research the influences of polarizing technique (time, temperature and voltage) on actuators, induce strains of IDE piezoelectric ceramics actuators is studied by a lot of experiments, from which the optimal polarizing technique is gotten.4. The Scaling effect and unsteady aerodynamic force generation by flapping wings of insects and small birds is analyzed. Motion equations for flapping wing and bionic wing are established. Then a set of velocity and acceleration equations for flapping wing and bionic wing are derived. The aerodynamic forces which produced by two flapping wings are calculated.5. The flapping models and bionic wings are designed, which are integrated with MFC units. Primary research experiments of the integrated wings have been done, which offer the directions for further study.