Image-based Multi-scale Analysis of Porous Piezoelectric Materials and Application to Bio-MIMS

点击翻译按钮获取中文摘要

Recently developed porous piezoelectric material has many attractive characteristics such as low Q-value. However, its microstructure has not been investigated three-dimensionally yet Hence, the correlation between the porous microstructure and the macroscopic properties has not been clarified, which prevents from designing the material systematically.Therefore, the first purpose of this study lies in the multi-scale and multi-physics analysis of porous PZT based on the automatic image-based modeling by means of nondestructive observation of the three-dimensional microstructures with X-ray micro-CT. In pursuit of this, the development of new iterative equation solver is essential to solve large-scale piezoelectric problem derived from voxel finite element method. The research group succeeded in developing a node-block preconditioner. Finally, a problem with approximately one million finite elements has been analyzed on a standard personal computer. It was applied to real porous PZT with different porosity ratios, and its effectiveness has been proved.One of the applications to bio-micro-electro-mechanical-system(bio-MEMS) is a pump to draw blood for health monitoring system. We have studied the structural design of a bimorph actuator with slit to obtain large stroke.The second application is the micro-needle drug delivery system. A testing machine was developed to observe the insertion of micro-needle into cultured human skin with controlled biaxial tension.Not only the linear analysis but also dynamic analysis has been studied. For fast dynamic multi-scale analysis, the model order reduction(MOR) method has been investigated used together with one of the multi-scale methods, the finite element mesh superposition method. It was found that the appropriate numbers of base vectors in MOR can lead to accurate enough dynamic analysis to capture both global and local responses. This results will open the door to future fast dynamic multi-scale piezoelectric analysis.