Analysis of Thermoelastic Dissipation in Microbeam Resonators Covered with Multiple Partial Coatings

Thermoelastic dissipation (TED) is a mechanism for intrinsic energy dissipation that governs the upper limit on microresonators' quality factor (Q-factor). The demands for high performance and diverse functionality have led to the development of MEMS resonators with increasingly complex structural geometries and materials. This work proposes an analytical framework to evaluate TED behavior in microbeam resonators coated with multiple partial coatings. By determining the one-way thermoelastic coupled equation in the thickness direction, the temperature function is obtained for each region, and TED model is derived by capturing the energy loss of each region within the framework of thermal energy method. The effectiveness of present framework is verified by comparing it with experimental data and finite element method (FEM) results. The developed TED model has an explicit closed-form expression that converges rapidly, and retaining only leading terms yields a simple TED model. Rules for applying the simple TED model to ensure accuracy are discussed. TED behaviors considering finite thermal contact conductance are comprehensively investigated. A methodology for a mixture of multiple partial coatings to suppress TED is proposed. This work is helpful in suppressing the TED and achieving high Q-factors for the microbeam resonators.