IMPACTS OF MATERIAL PERFORMANCE INDICES AND LENGTH SCALE PARAMETER ON THERMOE- LASTIC DAMPING IN MICRO/NANOPLATES AP- PLYING MODIFIED COUPLE STRESS THEORY

Energy dissipation in micro-and nanoscale resonators can be optimized by improving the thermoelastic-damping-limited quality factor. Maximizing energy dissipation is interrelated with the critical lengthof the resonator plates; by optimizing the dimensions, the peaking of energy dissipation can be diminished. However, classical continuum theories cannot explain the size effects related to mechanical behavior at micron or submicron sizes. In this study, isotropic rectangular micro-plates are used to analyze the size -dependent thermoelastic damping and its impact on the quality factor and critical dimensions such as critical length of micro/nano plates. Micro-and nanoplates using five different structural materials are analyzed to optimize quality factor, which depends on two material performance indices: thermoelastic damping index and thermal diffusion length.In our study, an expression for the thermoelastic damping limited quality factor is derived in terms of the material performance indices and simulated numerically using MATLAB R2015a. Accordingly, the maximum thermoelastic damping limited quality factor is attained for polySi with the lowest thermoelastic damping index and maximum critical length is obtained for SiC with the lowest thermal diffusion length. The impact of material length-scale parameters l, material performance indices, vibration modes, and boundary conditions on quality factor limited by thermoelastic damping and critical length are also investigated. Quality factor is maximized by selecting polySi as the structural material with higher internal length-scale parameters l. These results can help designers to engineer high-performance, low-loss resonators at micro/nanoscales.

Automated summary

This study analyzes the impact of energy dissipation and critical dimensions on the quality factor of micro- and nanoscale resonators. By optimizing dimensions and selecting appropriate materials, the quality factor can be maximized. The results of this study provide guidance for designing high-performance, low-loss resonators at the micro/nanoscale.