  We have derived a general formula for sensitivity optimization of gravimetric
sensors and use it to design a high precision and high sensitivity gravimetric
sensor using unidirectional carbon fiber epoxy composite (CFEC) guiding layer
on single crystal Mn-doped yPb(In1/2Nb1/2)O3-(1-x-y)Pb(Mg1/3Nb2/3)O3-xPbTiO3
(Mn: PIN-PMN-PT) piezoelectric substrate. The normalized maximum sensitivity
exhibits a decreasing tendency with temperature up to 55 degrees Celsius. For
the CFEC-on-Mn: PIN-PMN-PT sensor configuration with wavelength 24 {mu}m at 25
degrees Celsius, the maximum sensitivity can reach as high as 760.88 cm2/g,
which is nearly twice that of traditional SiO2/ST quartz configuration
gravimetric sensor.
