Strain Characteristics of Surface Acoustic Wave Resonators on X-Cut LiTaO3

This work investigates the strain characteristics of surface acoustic wave (SAW) resonators fabricated on X-cut LiTaO3 (LT) substrates with varied Euler angles for exploring potential applications in strain sensing. The simulation and experimental results show that both Rayleigh wave and shear horizontal wave can be excited in (90°,
$90^{\circ },\Psi \text {)}$
LT substrates when
$\Psi $
is ranged from 132° to 162°. The resonance frequencies of both Rayleigh wave and shear horizontal wave shift with applied strain. The strain coefficient of frequency (SCF) strongly depends on the acoustic wave propagation direction. The maximum sensitivities of Rayleigh wave and shear horizontal wave to applied strain are about -0.94 and -0.41 ppm/
$\mu \varepsilon $
for
$\Psi = 122^{\circ }$
and
$\Psi = 132^{\circ }$
, respectively. It is also found that some SAW resonators deposited on certain Euler angles exhibit insensitivity to applied strain. The results of this work provide valuable insights for designing and optimizing SAW strain sensors based on LT substrates.