Micro size effect of silicon material on the performance of micro-gyroscope

The size of micro-gyroscope is micron. In such a size, the material size effect which is ignored in the macro system will evidently affect the performance of micro-gyroscope. In this paper, from analyzing the effect of grains on behaviors of silicon material, a practical model similar to couple stress model is established by means of the concept of higher-order theory of elasticity. For the micro elastic beam structure in micro-gyroscope, an expression of the equivalent elastic modulus is derived. From calculating natural frequency of the micro-gyroscope, it is found that, the result calculated by considering the size effect is in agreement with the experimental one. If the size effect is not considered, the error between them is large.