Generalized thermoelastic analysis of thermo-optic switch multi-layer structure

Delaminating failure is the fatal failure mode of Micro Electro Mechanical Systems(MEMS) multi-layer membrane structures and severely affects the reliability of MEMS devices. In this work, a multi-layer membrane structural model of a thermo-optic switch is established under the framework of generalized thermoelastic theory, and the distribution of interlayer temperature, thermal mismatch stress and core refractive index is calculated. The effect of relaxation time on thermal mismatch stress and refractive index is discussed, and numerical results show that the thermal mismatch stress increases with the heating power. When the relaxation time rises to 10(-3)s magnitude, the thermal mismatch stress decreases, the core layer reaches a high steady-state temperature and the refractive index of the core layer expands. These results provide a new idea for the research and development of new devices; that is, the adoption of core layer materials with long relaxation time can improve the reliability of MEMS devices.