Experimental evaluation of resonant frequencies with associated mode shapes and power analysis of thermally actuated vibratory microgyroscope

This paper presents theoretically and experimentally determined modal behavior of thermally actuated gyroscopic sensor. A comparative analysis is carried out between experimental and finite element analysis (FEA) results. FEA is performed on the model to predict the expected mode shapes and resonant frequencies of the gyroscopic sensors experimentally. Experimental evaluation of the resonant frequencies and associated mode shapes is carried out using PolyTec Micro System Analyzer by separate in-plane and out-of-plane tests that produced frequency response data. Frequency response data showed that resonant frequencies of drive and sense mode are closely matched around 6 kHz. The drive mode is characterized by applying constant as well as variable current whereas sense mode is evaluated at constant AC voltages both at their resonant frequencies i.e. 6 kHz. Maximum displacement of 3 and 0.12 μm is achieved by drive and sense mode respectively at 225 mA^rms and 40 V_ac. Different mode shapes associated with the resonant frequencies are also experimentally characterized. A comprehensive performance analysis of thermally actuated gyroscope showed that drive mode displacement of 4.2 μm can be achieved by consuming 363.39 mW.