Design and Finite Element Analysis of a Micromechanical Open Angular-rate Sensor

This paper presents a design andsimulation of Z-axis micromechanical fluidic gyroscope based on the open gas flow channel. The gas flow field inside the sensitive device is calculated by utilizing 3-D transient finite element analysis based on fluid-solid coupling. The calculation results and test indicate that the sensitive fluidic chamber maintains a stable sensitive fluid in a complete cycle of vibration. The distance from the hotwires to the nozzle orifice satisfies the expectation of response frequency at L-Z = 1.8mm, and the best distance between the parallel lines is satisfied with the minimum expectation of non-linearity with Delta L = 0.7mm. When angular rate is applied, the velocity gradient between the hotwires r(1) and r(2) is enlarging with the angular increasing. The Z-axis gyroscope can achieve a sensitivity of 2.0 mu V/degrees/s, with a non-linearity less than 0.5%, with the power consumption of 5.4mW, with the hotwires resistance of 3 Omega and TCR of 2600 degrees C, within the input range of +/- 120 degrees/s.