Piezoelectric Micro-sensor Cantilever Structure Optimization Design

With the rapid development and wode application of MEMS technology, the performance micro-sensor has also been improved. In the case of MEMS fabrication technology continues to mature, it has been able to produce a composite micro-cantilever structure of piezoelectric micro sensors, with the factor that we have a mature production process, this paper mainly want to optimize the structure of PZT piezoelectric pressure micro-sensor, we use the genetic algorithm to optimize the model we created, and then we simulate a group data come from before and after optimization, Comsol Multiphysics software is used in this progress. The result of simulation plays a supplement explain to the optimization.First establish the structure of the PZT piezoelectric pressure micro-sensor model, use a multi-layer structure of composite cantilever, and then derive the loads-electric conversion equation under external loads on the piezoelectric micro-cantilever, select the tewo design variables, the deflection angle and the length of the cantilever, under the same conditions in the control of other parameters, to analyze the impact of the variables on the amount of electric charge of the micro-sensor output.Then using genetic algorithm to solve the optimization, first we input a known size parameter model of the micro-structure sensor, and we get the result, the deflection angle of the micro-structure is1.206, the shape is triangular. In order to verify the results, we use three groups of27samples to expand the analysis. The result prove that in the case of the shape and material of a predetermined structure distribution, this result having universality.Finally, we use Comsol to simulate a sample in a set of data, the main simulation content conclude its steady-state analysis and the characteristic frequency analysis, in the steady-state analysis, we get the results strain deformation and stress voltage maps, and besides, we can also verify the assumptions when we create the model. During the characteristic frequency analysis, we get the first sixth-order features, extracted from the simulation results we obtained and compared the size of the characteristic frequency and maximum deformation displacement, in the result, we can see that the structure after optimized is superior to the structure before optimization. Micro-sensor simulation, also plays a very important role in its micromachining process.