In this paper, a new vibration structure is presented for the measurement of analyte concentration of an aqueous solution, using a magnitude change of frequency response induced by the mistuned fluid-structure coupled vibration of the suggested structure immersed in a liquid. Firstly, the measurement principle is explained by analysing natural characteristics and mistuned responses of the suggested symmetric structure by using finite element method (FEM). Then added mass effect induced by the fluid-structure interaction is formulated, by which the variations of the analyte concentration can be manifested into the change of the added mass acting on the suggested structure. Based on the added mass effect and the mistuned vibration characteristics of the proposed structure, the resonant amplitudes of the structure are investigated under different fluid densities and this method shows much higher sensitivity than the frequency changes used in previous works. Lastly, the experimental system was optimized and simulated for detecting glucose concentration at human blood glucose level and noticeable differences were observed for different glucose concentrations. The results reveal the feasibility of glucose measurement for health sensor applications.

Mistuned vibration,Fluid-structure interaction,Analyte concentration,High sensitivity