依據本研究之結果歸納出以下幾項重點:
(1) 對壓電複合材料換能器而言，影響換能器輸出效率之因素包括耦合因數K33、 介電損耗因數tanδ、品質因數Qm、聲阻抗Za與陶瓷柱間的干擾，雖然複合材料 換能器之耦合因數比陶瓷換能器高且聲阻抗比陶瓷換能器低，然而，高的介 電損耗與共振機械損耗致使複合材料換能器產生許多熱能，進而降低本身之 輸出效率。換言之，影像用之換能器所追求的高耦合因數並無法直接表示HIFU 換能器有高的輸出效率。
(2) 隨者陶瓷寬高比的上升，頻寬會有上升的趨勢，而品質因數、聲阻抗以及電 聲轉換效率則會有下降的趨勢，而隨者陶瓷體積比的提高，聲阻抗會有上升 的趨勢。
(3) 對 1-MHz 壓電複合材料換能器而言，基本上電聲轉換效率會隨著陶瓷體積比 的增加而上升，然而，當陶瓷柱間之間隙小於0.2mm 時，陶瓷柱間的干擾會 大幅提升，進而影響波的輸出而降低輸出效率。
(4) 與陶瓷換能器相較，壓電複合材料換能器的優點之一在於聲阻抗低，表示其 傳遞至水介質的波較多，反射的波較少，這樣會有效的降低換能器發熱的現 象。
(5) 因為聚焦換能器發射出去的波會有效地聚集，所以轉換效率會比平面換能器 還要來得更高。
對於材料的選用以及實驗參數的設定都還有很多可以研究與討論之處。就複 合材料方面而言，因為樹脂的種類眾多，例如文獻[3]中就有比較低、中、高密度 的樹脂，或者是在樹脂中添加額外的物質去改變樹脂的特性或硬度，例如添加微 米球或氧化鋁，這些都有可能會改變陶瓷柱之間干擾的現象，導致轉換效率有所 改變。就實驗參數方面而言，可以增加不同陶瓷寬高比以及陶瓷體積比參數的壓 電複合材料，或者可以改變陶瓷柱的面積大小，因為從文獻[7]的結果中提到在相
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同陶瓷體積比的條件下，陶瓷柱面積越小的複合材料其d33值會越高，而d33值與振 動的強弱有關，這結果可能會有效的提升轉換效率。
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