Finite element modeling of the thermo-electro-mechanical coupling in pyroelectric infrared sensor arrays

For the example of a Lithiumtantalate (LiTaO3) sensor array, the coupled thermo-electro-mechanical fields are examined using the finite element method. The temperature distribution is computed in a preliminary thermal analysis, and the numerical results are compared with an analytical model. The calculated temperature field is used as input for a subsequent electro-mechanical analysis, where the thermo-elastic and the pyroelectric source terms axe simulated by body forces and body charges, respectively. The investigations of various FEM-models showed, that different mechanical boundary conditions and the piezoelectric coupling of LiTaO3 influence the electric system response by only about 6...7%.