A Multi-Parameter Decoupling Method with a Lamb Wave Sensor for Improving the Selectivity of Label-Free Liquid Detection

Abstract

In this paper, a liquid multi-parameter decoupling method with only one Lamb wave sensor is presented. In a Lamb wave sensor, antisymmetric modes (A₀₁ mode for low frequency, A₀₃ mode for high frequency) and symmetric modes (S₀ mode) are used to detect multiple parameters of a liquid, such as its density, sound velocity, and viscosity. We found they can play very different roles in the detections. For example, the A₀₁ mode is very sensitive to the liquid’s density but the A₀₃ mode is sensitive to the sound velocity. Here, the A₀ mode is used to identify the density of the detected liquid and with this density value we obtained the viscosity by the amplitude shifts of the S₀ mode. This could be a way to distinguish an unknown liquid with high sensitivity or to solve the problem of selectivity of label-free detection on biosensors.

Keywords

• Lamb wave sensor
• density
• sound velocity
• viscosity
• determination of multi-parameters