Abstract <p>A higher-order theoretical model for transversely isotropic piezoelectric microplate is developed by incorporating both strain gradient and polarization gradient effects, aiming to investigate its electromechanical coupling behavior at the micro-/nano-scale for MEMS applications. The model accounts for flexoelectric–piezoelectric coupling and is applied to analyze the static and dynamic behaviors of PVDF microplates using the Fourier series method. Results indicate that as the plate thickness decreases to the microscale, the flexoelectric effect becomes dominant, significantly influencing the electric potential distribution. The induced potential exhibits asymmetric characteristics due to the superposition of flexoelectric and piezoelectric effects. Additionally, the deflection and potential responses are highly sensitive to plate thickness, load magnitude, and excitation frequency. Resonance amplification is observed near the natural frequency, with synchronized variations in potential and deflection. This work provides a unified multi-physics framework that captures the size-dependent electromechanical behavior of piezoelectric microstructures, offering theoretical support for the design and optimization of MEMS sensors and energy harvesters.</p>