Study On Longitudinal Vibration Measurement Of Solidly Mounted Resonator Based On AFM

Solidly Mounted Resonator(SMR)is a kind of MEMS device which is widely used in bio-sensing field.SMR has the characteristics of vibration frequency up to 20 GHz,the vibration amplitude of sub-nanometer and its application in liquid.However,conventional longitudinal vibration measurements,such as Interferometry,Micro-Laser-Doppler and Commercial Atomic Force Microscope,are hard to characterize the features of these devices accurately,this limits the application of such devices to a great extent.In this paper,an improved longitudinal vibration measurement technology based on AFM is studied on the longitudinal vibration characteristics of SMR through simulation and experiment in air and in liquid,separately.The technology is also used to study the relationship of vibration transfer from the resonator to AFM cantilever and it affords theoretical support for the application of these resonators.This article mainly focuses on the following works:(1)Aiming at the feature of the longitudinal vibration measurement technology,the process of the vibration transfer from vibrating devices with ultra-high frequency through air to AFM cantilever in tapping mode in air is studied and the corresponding numerical calculation is analyzed by Matlab software;(2)The process of the vibration transfer from vibrating devices through liquid to AFM cantilever in tapping mode in liquid is studied and it is simulated by ANSYS software based on the principle of Fluid-Solid-Coupling.Besides,the simulation results theoretically explain the phenomenon of the vibration amplification from SMR to AFM cantilever.(3)Design and build a system of longitudinal vibration measurement technology.The system is used to detect vibration frequency and vibration amplitude of SMR in air and in liquid.During the detection process,the tapping mode and contact mode have been employed.Besides,Two functions “Tip-offset” and “Deflection Setpoint” are applied to test the dynamic response of water above SMR as well as probe the influence of the interaction force between SMR and AFM cantilever on vibration measurement.