Design on a bending stress measurement system of micro-gear with fiber Bragg grating

Micro-gears are key components in Micro-Electro-Mechanical System (MEMS). For micro-gears, bending strength analysis is not only an effective way to improve gear bearing capacity, but also the foundation of tooth profile optimization and vibration reduction. In addition to theoretical calculation, it is necessary to measure bending stress for more accurate strength analysis. In this paper, a bending stress measurement system of micro-gear with fiber Bragg grating (FBG) is designed. First, the dynamic bending stress of given micro-gears is calculated with finite element method(FEM). The results of FEM, especially the maximum bending stress, are the reference for the parameters of the measurement system. Then, the bending stress measurement system is discussed with emphasis on principle of the system, probe installation, parameters determination of FBG, light transmission and sensing model of the system. The studies done in this paper prove that the bending stress measurement system proposed is feasible. The application of this system can guide the design process of micro-gears.