The effect of thermoelastic damping on the total qfactor of. Thermoelastic damping effect analysis in micro flexural resonator of. Eigenvalues, resonance poles, and damping in mems d. This tiny, bulkfabricated device, measuring less than 110th of an inch. Thermoelastic damping depending on vibration modes of nano beam resonator 321 coupled thermoelastic equations.
One of the major dissipation mechanisms is thermoelastic damping ted that needs an accurate consideration for prediction. Microrings are a common resonator of mems a microelectromechanical system, which are widely applied to mems sensors and actuators 14. Thermoelastic damping in microbeam resonators sciencedirect. Vents reduce the structural rigidity and thus reduce the resonant frequency. In this paper, the quality factor of the resonator is computed by. The effects of geometry on the energy dissipation induced by thermoelastic damping in mems resonators are investigated numerically using a nite element formulation. For vacuum encapsulated devices, thermoelastic damping ted and support loss are the most important damping mechanism in mems resonators. Direct detection of akhiezer damping in a silicon mems resonator. Intuitive for mems engineer 3d model construction from gdsii files streamlined operation for common mems simulations, including. Thermoelastic damping is recognized as a significant loss mechanism at room temperature in microscale beam resonators. Geometric effects on thermoelastic damping in mems resonators y.
Pdf damping effects are very important in memsbased sensors and actuators. Thermoelastic damping and support loss in mems ring. Entropy generation and thermoelastic damping in the in. Modeling of thermoelastic damping in mems resonators. The stress brings about deformation, where materials heat under compressive stress and cool under tensile stress.
Thermoelastic damping in resonators is studied using the finite element method. Thermoelastic damping, which arises when you subject a material to cyclic stress, is an important factor when designing mems resonators. Geometric effects on thermoelastic damping in mems resonators. We examined the most important mechanisms that are believed to limit the quality factor in mems tuning fork resonators i. In this paper, the governing equations of coupled thermoelastic problems are established based on the generalized thermoelastic theory with one relaxation time. The perturbation analysis is applied to derive a linear eigenvalue equation for the exponentially decaying rate of the mechanical oscillation. An investigation on thermoelastic damping of highq ring. The physical parameters of single crystal silicon beam used for simulation are shown in table 1. Investigation of energy dissipation in low frequency vibratory.
This paper considers ring resonator based rate sensors and investigates the influence of design changes to the ring and support legs on thermoelastic damping, which is the dominant dissipation mechanism. Pullin, electrostatic spring softening coupled thermomechanical ex. Coventorware tutorial university of california, berkeley. Thermoelastic damping, thermal stability piezoelectric effects ex. A finite element analysis of thermoelastic damping in vented mems. Yi department of mechanical and materials engineering, university of denver, denver, co 80208, usa received 25 august 2006. Thermoelastic damping in microand nanomechanical systems.
Design strategies for controlling damping in micromechanical and. Pdf damping effects in mems resonators researchgate. Mems and nems resonators generally contain ele ments which vibrate in either torsional or flexural modes. Direct detection of akhiezer damping in a silicon mems. This thesis focuses on understanding and quantifying the effects of thermoelastic damping and support loss on the damping performance of. Request pdf engineering mems resonators with low thermoelastic damping this paper presents two approaches to analyzing and calculating thermoelastic damping in micromechanical resonators. The vent width plays a more important role than the vent length.
A finite element analysis of thermoelastic damping in. Vents at the clamped end can raise the quality factor significantly. T he thermoelastic damping as we ll as frequ en cy of the structure of. The known sources of energy loss in micromechanical beam resonators are air damp ing, acoustic loss through the anchor, thermoelastic damping, and internal. Engineering mems resonators with low thermoelastic damping. Thermoelastic damping is one of the most important energy loss mechanisms in mems resonators especially when the resonator is miniaturized to achieve higher frequencies. For applications requiring high performance angular rate measurements it is important to be able to design mems rate sensors with high quality factors q. It has been verified that thermoelastic damping is a significant loss mechanism near room temperature in mems resonators. Thus, due to the resulting heat flux, energy is lost to bring about this damping. Bindel computer science division department of eecs.