Acoustic Energy Regulation and Quality Factor Improvement in Acoustic Liquid Sensors by Optimized Structural Design

Abstract

We report acoustic sensors for liquid detection by designing a composite structure. By controlling the substrate thickness and the wavelengths are at the same order, the longitudinal wave energy is regulated and the peak values of the quality factor Q up to 1270 are realized. Meanwhile, part of the energy is regulated by two pairs of optimized Bragg reflecting structures in which the functions of the liquid layer are enhanced and Q becomes more stable relative to the thickness of the micro-channel. These features present conveniences for fabrications and give high sensitivities in liquid environments.

Enhanced resonance transmission of acoustic waves based on asymmetric excitation of Lamb waves in phononic crystals with wedges-like structures

“…The value of Q-factor is 4.5 times more than the previous work. 20 It is also observed that the Df c of the two liquids increases from 0.00051 in case (a) to 0.00054 in case (b) with the increasing f c . However, the corresponding transmittance decreases a little following the narrower full width at half maximum.…”