細長U型壓電能量採集器之分析

Abstract

在傳統的壓電懸臂樑能量採集中，所受到的應變並不均勻，差異性非常大，造成了我們採集能量的效率低下，系統效能較差。因此，本研究提出一種細長U型壓電能量採集器，進行了較爲深入的理論分析以及實驗研究，以用于於改善應變的分佈情況，以此來提高能量輸出效率。在有限元素（FEM）以及數學模型模擬中發現，在未貼滿壓電片的時候，發現此結構高度越高或者長度越長，總應變面積較大，但最大應變值、位移值較高，並且此結構的應變分佈較傳統的懸臂樑分佈更為均勻。在實驗與模擬中，較高高度的U型樑採集電壓在串聯時比高度較低的的U型樑提高了約為15%，並聯時提高約23%；在與雙壓電懸臂樑的比較中，在模擬上也發現其採集到的電壓也提高了12.9%。而在全貼滿的情況下，也得到類似的情況，較高高度的U型樑比高度較低的的U型樑應變分佈面積更大，採集電壓提高了11.38%；而跟雙壓電懸臂樑比較可發現採集電壓提高了27.6%。而從應變的分佈來觀察，發現全貼滿壓電片時，U型樑的最大應變值比懸臂樑的小很多，但是採集電壓卻得到了大幅提高；在自身的比較當中也可發現，同等條件下，高度越高或長度越長，其位移、應變會較大，與此同時，採集到的電壓也會相對較高。

In the traditional piezoelectric cantilever beam energy harvesting, the strain received is not uniform, and the difference is very large, which results in low efficiency of our collected energy and poor system performance. Therefore, this paper conducts in-depth theoretical analysis and experimental research on a slender U-shaped piezoelectric energy harvester, which is used to improve the strain distribution to improve the energy output efficiency. In the finite element method (FEM) and mathematical model simulations, it is found that when the piezoelectric sheet is not covered, the height of the structure is higher or the length is longer, the total strain area is larger, but the maximum strain value is higher, and the structure is high. The strain distribution is more uniform than the traditional cantilever beam distribution. In the experiment and simulation, the U-shaped harvested voltage of the higher height is increased by about 15% compared with the lower height U-shaped; in comparison with the bimorph, it is also found in the simulation. The voltage has also increased by 12.9%. In the case of full filling, a similar situation is obtained. The U-shaped of higher height is more evenly distributed than the U-shaped of lower height, and the harvesting voltage is increased by 9.16%. With the bimorph, U-shaped comparison found that the acquisition voltage increased by 27.6%. From the distribution of the strain, it is found that the maximum strain of the U-shaped is smaller than that of the cantilever beam regardless of whether it is covered with the full piezoelectric piece, and it can also be found in its own comparison. Under the same conditions, the higher the height or the longer the length Long, the strain will be larger, and the voltage collected will be relatively high.