This work aimed to study the thermo-electro vibration of a piezoelectric micro-plate resting on the orthotropic foundation. To catch the small-scale effects of the structure, couple-stress theory was employed. Motions of the structure were modelled based upon different shear deformation theories including exponential, trigonometric, hyperbolic, parabolic, and forth-order shear defor-mation theories. These modified shear deformation theories are capable of considering transverse shear deformation effects and rotary inertia. Equation of motions are derived with Hamilton’s prin-ciple and to solve these equations an analytical approach is applied. Besides, Effect of different boundary conditions including SSSS, CSSS, CSCS, CCSS and CCCC are investigated. The pre-sent results are validated with the previously published results. In the result section, the influences of various parameters such as increasing temperature, boundary conditions, foundation parameters, thickness ratio, aspect ratio, external volatage, and length scale on the natural frequencies of the plate are illustrated in detail.
