多铁材料微振发电器件的物理、方法与技术

Low frequency and micro-amplitude vibrations widely exist in nature. Changing the mechanical energy of micro-vibrations into electric one will be another way of harvesting green energy. Besides the well-known piezoelectric effect, we explored other three independent methods of electric energy harvesting based on micro-vibrations using ferroelectric and ferromagnetic oscillations, respectively. They can be called micro-vibration-based generation of stress-permeability, displacement-permeability and displacement-capacity, respectively. Furthermore, matching the ferroelectric and ferromagnetic oscillations properly will lead to more kinds of composite micro-vibration-based generators, namely, multi-ferrous micro-vibration-based generator. And our experiments have shown that the generating efficiency of the composite micro-vibration-based generators is often much greater than the sum of two independent generators. This project aims at, from experiments and theoretical analysis, 1) systematically studying the mechanisms, methods and techniques of the micro-vibration-based generation using ferroelectric and ferromagnetic oscillations, 2) investigating the effects of the sizes and parameters of the materials involved and the geometrical structure on the generating efficiency of the multiferrous micro-vibration-based generators under stress and unrestraint, 3) studying the mechanisms of the ways of matching ferroelectric and ferromagnetic oscillations to be multiferrous vibration-based generator in advancing the generating efficiency, and to establish sound experimental and theoretical foundations for promoting the research of micro-vibration-based generation into practical applications.

自然界普遍存在着低频微幅机械振动。将这样的微振动能量转化为电能将是又一种清洁能源获取方式。除了众所周知的压电效应之外，我们利用铁电振动和铁磁振动分别开发出另外三种独立的微振动- - 电能转化方式。它们分别为，应力变磁导型，位移变磁导型，以及位移变电容型微振发电。更有甚者，将铁电振动和铁磁振动做适当匹配后可获得更多种类的复合（或多铁）微振发电器件；并且我们的实验显示，这样的多铁微振发电器件的发电效能常高于两种独立模式的发电效能之和。因此，本项目旨在从实验及理论出发，1）系统的研究有应力及无约束条件下铁电振动及铁磁振动的发电机理、方法和技术；2）探索材料参数，尺寸及几何外形对复合材料器件发电效能的影响；3）研究将铁电振动和铁磁振动匹配成复合多铁微振发电器件的方式对提高复合器件发电效能的作用原理，4）并将多铁微振发电器件集成为微振发电电池或电堆。为使微振发电技术走向实际应用奠定必要的理论和实验基础。

本项目执行期间，我们基本完成了所拟定的研究计划和任务。共研制了铁磁微振型、驻极体微振型、和单悬臂梁及双悬臂梁的铁磁-铁电混合型四种微振发电器件。实验显示单悬臂梁型微振发电器件具有最高发电效率。以此为基础，我们制备了小规模的微振发电集成模块，获得了可以点亮3-4张LED电珠的发电效果。更大规模的微振发电装置仍在进一步研制和完善之中。项目执行期间共发表了相关（标有由该项目资助的）论文16篇，被SCI数据库收录16篇。有关专利也正在申请之中。该研究结果为扩大和普及微振发电技术提供了可靠的实验基础。