Study on a Piezoelectric Gyroscope in Thickness-Shear Mode

Based on the theories of piezoelasticity, a new piezoelectric gyroscope in thickness-shear mode is studied. The gyroscope is made of a titled c-axis lithium niobate piezoelectric plate with a ferroelectric inversion layer. The thickness-shear motions of the plate can be excited by only one electric field through thickness. When the thickness-shear motions in the length direction are driven by a harmonic voltage in the thickness direction and the plate rotates around the normal axis at the same time, the Coriolis force due to the rotation and the relative motions of the particles will generate thickness shear motions in the width direction of the plate and the output voltage which can be measured to determine the angular velocity of the rotation. The results show that the working mode of the gyroscope is the second-order thickness shear mode, and the output voltage can be used to detect the angular velocity of the gyroscope.