Enhanced sensitivity of wireless chemical sensor based on Love wave mode

A 440 MHz wireless and passive Love-wave-based chemical sensor was developed for CO, detection. The developed device wits composed of a reflective delay line patterned oil 41 degrees YX LiNbO3 piezoelectric substrate. a poly(methyl methacrylate) (PMMA) waveguide layer, and Teflon AF 2400 sensitive film. A theoretical model is presented to describe wave propagation in Love suave devices with larvae piezoelectricity and to allow the design of an optimised structure. In wireless device testing using a network analyzer. infusion of CO2 into the testing chamber induced large phase shifts of the reflection peaks owing to the interaction between the sensing film and the test gas (CO,). Good linearity and repeatability were observed ill CO2 concentrations of 0-350ppm. The obtained sensitivity from the Love wove device wits approximately 7.07 degrees ppm(-1). The response properties of the fabricated Love-wave sensor in terms of linearity and sensitivity were provided. and it comparison to surface acoustic wave devices wits also discussed.