振動模式下壓電雙晶片能量擷取之分析與量測

本文主要利用壓電雙晶片在單邊固定之邊界條件下，施以第一模態之共振頻率予以激振，以量測此結構之發電電壓與功率，亦即量測振動能經由壓電效應轉換為電能之效應。經由雙晶片的並聯與串聯模式，進行兩種不同連接方式之發電量量測與差異比較，結果顯示在並聯模式下，其發電電壓值遠低於串聯模式之電壓值。為了與實驗所得之結果作比較，本文使用有限元素法(FEM)進行模擬壓電雙晶片之第一共振頻率，及其發電電壓與功率，經比較結果顯示兩者具有相當不錯之一致性。最後本文探討壓電雙晶片在不同壓電卅金屬層之長度、寬度、厚度比時，其與外加負載電阻變化造成輸出電壓與功率之改變，進而應用數值模擬之方式，提供結構尺寸之最佳化，以提高發電效率。

關鍵字

壓電雙晶片；能量擷取；振動；有限元素

並列摘要

Piezoelectric transducers are widely used in electromechanical sensors, actuators, non-destructive testing devices as well as electro-optic modulator etc. Piezoelectric effect is applied to many modern-engineering applications because it expresses the connection between the electrical and mechanical fields. Piezoelectricity describes the phenomenon that the material induces an electric charge when subjected to stress and, conversely, induces strain when the electric field is applied. In this article, the three-layered piezoceramic bimorph with clamped edge (or cantilever) boundary conditions are employed to carried out the analysis of vibration-based piezoceramic energy harvester. The influences of geometric parameters (layer-thickness ratios for metal/ piezoceramic layers) and electrical connecting conditions on the power output for the three-layered piezoceramic bimorph are studied in terms of the finite element simulation. After finishing the finite element calculation, the three-layered piezoceramic bimorph will be employed to perform the power output experimental measurement by the self-arranged experimental setup. It is shown that the numerical calculations performed by the finite element method (FEM) agree well with those obtained by the experimental measurements. The results will provide the relative information for energy harvesters with optimal and compact design.