Degenerate modes of operation in lithium niobate sensors

The properties of lithium niobate make it an ideal choice for electromechanical sensors and it has therefore seen extensive use in surface acoustic wave devices. However, its trigonal crystal structure makes it difficult to design sensors based on degenerate dual frequency operation such as gyroscopes and degenerate mode biosensors. This work looks at how sensor geometry may be optimized to compensate for the asymmetry in the lithium niobate material properties. The effect of crystal orientation on the frequencies of vibration of a diaphragm resonator structure is explored and design geometries proposed. The theoretical work identifies appropriate crystal orientations and sensor geometries to restore modal degeneracy.