孔洞駐極體的研發及在靜電揚聲器上的應用

Abstract

本文利用駐極體材料具有穩定儲存電荷的特性，取代傳統靜電揚聲器的直流偏壓放大元件，並完成駐極體揚聲器單體的研製。駐極體材料研究主要以溶液型非氟化物的聚合物改良為主，分別探討混合相異聚合物與極性分子添加劑對聚合物的儲電特性影響。研究過程中，透過掃描電子顯微鏡觀察材料微型態變化，並進行熱衰減分析來討論駐極體特性影響的生成原因。所得成果同時改善了高分子聚合物駐極體與金屬層接著的問題。實驗結果發現，經過添加特定比例的極性化合物與異質高分子，可有效的提升駐極體電荷儲存達到1000 。本文最後成功將改良的孔洞聚合物製作成駐極體耳機，此耳機之共振頻率約為400Hz，在以100 電壓驅動的狀況下，所產生的聲壓大小為98dB。

In the thesis , we utilized the stable charge storing capabilities of electret to replace the DC to DC converter based biased circuit used in electrostatic loudspeaker and developed an electret speaker. Regarding the elecret materials development, the research efforts concentrated on improving the solution type non-fluoride polymer. Influence of electret properties through mixing heterology polymer and adding the polar molecule into polymer were studied. Through observing the material surface morphology and cross-sections by using scanning electron microscopy and performing materials thermal discharge condition, factors influence the electret properties were discussed. In addition, adhesion between the electret polymer and the metal layer were improved as well. From the experimental results, it was identified that adding specific ratio of polar molecule into polymer can produce the proper porous structure to enhance charge storage capability to -1000 . In the thesis, we successfully utilized porous electret polymer to develop an electret headphone. This newly developed headphone has 400Hz resonance frequency and can achieve 98 sound pressure when driven by 100V signal.