Bending dynamics of bidomain LiNbO₃ single-crystalline bimorphs

This study examines the bending dynamics of cantilevered single-crystalline bimorphs made from bidomain LiNbO₃ (BLN), emphasizing the interaction between bending resonances, antiresonances, and torsional vibrations. Combining theoretical modeling and experimental validation, we demonstrate that a 1D analytical model, based on classical beam theory, surpasses FEM modeling in predicting bending resonances, particularly in the low-frequency range. The analytical model provides precise positioning of resonant frequencies, enabling the strategic alignment of torsional resonances with bending antiresonances, as confirmed experimentally. Our findings underscore the high predictability of BLN-based bimorphs, allowing accurate descriptions of their behavior at bending resonances, antiresonances, and piezoelectrically passive torsional resonances. Unlike glued actuators made of lead-based ceramics, BLN bimorphs offer superior thermal stability, long-term reliability, and predictable performance. These properties, combined with the availability of commercially produced LN crystals, position BLN-based bimorphs as ideal candidates for MEMS applications, enabling advanced sensing and actuation solutions with reduced reliance on complex feedback loops.