We have derived a general formula for sensitivity optimization of gravimetric sensors and have used it to design a high sensitivity gravimetric sensor using unidirectional carbon fiber epoxy composite (CFEC) waveguide layer on (1 - x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 (PZN-xPT) single crystal substrate with the carbon fibers parallel to the x1 and x2 axes, respectively. The normalized maximum sensitivity (Smfλ)max exhibits an increasing tendency with the decrease of (h/λ)opt and the maximum sensitivity (Smfλ)max increases with the elastic constant c66E of the piezoelectric substrate material. For the CFEC/c poled PZN-7%PT single crystal sensor configuration, with the carbon fibers parallel to the x1 axis at λ = 24 μm, the maximum sensitivity (Smfλ)max can reach as high as 1156 cm2/g, which is about three times that of a traditional SiO2/ST quartz structure gravimetric sensor. The better design selection is to have the carbon fibers parallel to the direction of propagation of Love wave in order to obtain the best sensitivity.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)