Vibrating Flexoelectric Micro-Beams as Angular Rate Sensors

We studied flexoelectrically excited/detected bending vibrations in perpendicular directions of a micro-beam spinning about its axis. A set of one-dimensional equations was derived and used in a theoretical analysis. It is shown that the Coriolis effect associated with the spin produces an electrical output proportional to the angular rate of the spin when it is small. Thus, the beam can be used as a gyroscope for angular rate sensing. Compared to conventional piezoelectric beam gyroscopes, the flexoelectric beam proposed and analyzed has a simpler structure

Vibrating Flexoelectric Micro-Beams as Angular Rate Sensors

We studied flexoelectrically excited/detected bending vibrations in perpendicular directions of a micro-beam spinning about its axis. A set of one-dimensional equations was derived and used in a theoretical analysis. It is shown that the Coriolis effect associated with the spin produces an electrical output proportional to the angular rate of the spin when it is small. Thus, the beam can be used as a gyroscope for angular rate sensing. Compared to conventional piezoelectric beam gyroscopes, the flexoelectric beam proposed and analyzed has a simpler structure

Effects of Electrode Off Centre on Trapped Thickness-Shear Modes in Contoured AT-Cut Quartz Resonators

We investigated thickness-shear vibrations of a contoured, AT-cut quartz resonator with a pair of electrodes displaced from the resonator centre. The scalar differential equations by Stevens and Tiersten for thickness-shear vibrations of electroded and unelectroded quartz plates were employed. Based on the variational formulation of the scalar differential equations established in a previous paper and the variation-based Ritz method with trigonometric functions as basis functions, free vibration resonance frequencies and trapped thickness-shear modes were obtained. The effects of the electrode off centre on resonance frequencies and mode shapes were examined. When the electrode off centre is about one hundredth of the electrode length, the relative frequency shift is of the order of one part per million, significant in certain resonator design and applications. The electrode off centre also causes the loss of symmetry of modes, which has an adverse effect on resonator frequency stability under a normal acceleration

Boundary Formulation And Numerical Analysis Of Elastic Bodies . . .

The behavior of an elastic body with surface-bonded piezoelectric films is studied in this paper. The elastic body is modeled by the three-dimensional equations of elasticity, while the thin piezoelectric film is modeled by the two-dimensional equations of piezoelectric shells. It is shown that the governing equations can be written as a system of boundary integral--differential equations. These equations are solved numerically by the boundary element method in an example