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Abstract:This paper presents an analytical study of the nonlinear effect of squeeze film damping on the previously designed ring shape anchored contour mode RF MEMS disk resonators. Varations of damping coefficient and stiffness constant of the resonator due to squeeze film phenomenon are evaluated and their efects on quality factor of the resonator is calculated. Analytical calculations mention that due to ultra high spring constant of the resonator, resulting frequency pulling and damping related to this effect could be neglected. Based on these derivations, there is no requirement for high price
vacuum packaging for these resonators for increasing their quality factor. Extracting of the behavioral equations for the resonator in the presence of squeeze film effect is crucial in design of resonators in packaging, fabrication process and total cost points of view.

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In this paper, a fluidic biosensor with possibility to fabricate by Micro-Electro-Mechanical Systems (MEMS) technology is proposed for biomedical mass detection and lab-on-chip applications. This is designed by electromechanical coupling of harmonic micromechanical resonators with harmonic springers as a mechanical resonator array. It can disperse mechanical wave along the array by electrostatic method using interdigitate capacitors as actuators and sensors. It has some vital advantages like: low cost fabrication method, low fluidic interference damping effect, and high sensitivity with large absorbent area. In order to estimate the sensitivity of the proposed biosensor against the mass perturbation, the measurability of capacitance changes and fluidic interference damping effect, the stimulated analysis is conducted by COMSOL. It results, a suitable sensitivity and possibility to measure the biosensor outputs by available electronic instrumentations.