具有彈性底座之小型振動發電機

Abstract

利用壓電材料來發電是現在相當熱門的研究，較多的研究著重在發電機構的設計或發電量的多寡，未見對壓電片本身動態特性的研究(例如:共振頻率)。本研究於壓電彎片與底座之間，加入已知彈簧係數之彈簧與已知質量大小之印刷電路板，來達到彈性底座的效果，進而改變壓電彎片的共振頻率，使其更接近周圍環境的振動頻率。我們研究不同的彈性底座，以找出能使壓電彎片產生更大的發電量的彈性底座。本研究也討論雜訊的處理，將利用同軸電纜或接地等方式來減低雜訊的影響。本研究探討了不同彈性底座對壓電彎片發電量的影響，在馬達搖擺振幅為0.9度、頻率為15Hz且彈性底座之質量比a為4，剛性比r為2時，獲得最佳的發電電壓90mV和396nW的發電效果。

Nowadays the research on harvesting energy using piezoelectric generators is in great demand. Most research puts emphasis on mechanism design or power generation method, but few on the dynamic properties of piezoelectric benders, e.g.resonant frequency. This work achieves the effect of elastic base by adding springs with prescribed stiffness and a printed circuit board with given mass between piezoelectric benders and bases to make the resonant frequency of piezoelectric benders close to the low frequency of ambient vibration. To look for the elastic base which can make piezoelectric benders generate more electric power, we compare different elastic bases. Accordingly, more electric power is generated from piezoelectric generators using a designed elastic base. We have compared different elastic bases based on power generated by piezoelectric benders. We obtained the best result of 90mV and 396 nW when index a equals 4 and index r equals 2.