The present research puts forward a more comprehensive version of the double Legendre orthogonal polynomial method (DLOPM) to investigate the effects of the inner radius and radial wall thickness on the vibration properties of piezoelectric annular micro-electro-mechanical system (MEMS) oscillators with partial electrode coverage. The semi-analytical framework enables computationally efficient parametric exploration of resonator performance. The new approach utilizes Legendre polynomial expansions of higher order and region-specific window functions for the imposition of precise mechanical and electrical boundary conditions, thus making accurate wave propagation modeling and the influence of outer-region metallization possible. The study points out the essential effect of the inner-to-outer radius ratio on the respective and antiresonant frequencies along with dynamic electromechanical coupling coefficients (DEMCCs). Interestingly, the third mode can have a DEMCC greater than that of the fundamental mode, this being especially the case in devices with thin radial wall thicknesses, where the increase can be as much as 2.03 times when compared to solid disk configurations. Comprehensive examinations of dispersion curves, frequency parameters, admittance response patterns, and electric field distributions give a better understanding of the electromechanical characteristics of partially metallized annular resonators. The results of this study are particularly important in the optimization of MEMS devices for future roadway support applications which require advanced sensors and resonators for efficient structural health monitoring. The findings also provide design guidelines for a broader range of applications, including RF filters, piezoelectric transformers, and vibration energy harvesters. Moreover, the study findings also bring to light the ability of these MEMS devices to be a game changer in the future roadway support applications by offering highly accurate and quick monitoring systems. Research of this nature ultimately points towards the incorporation of such advanced piezoelectric MEMS resonators in future roadway support applications and thus the smart development of roadways.
Yang et al. (Thu,) studied this question.