外部電極配置對氦氣常壓電漿束之活性物質生成及殺菌效率之研究

Abstract

本研究主要致力於使用氦氣為主的常壓電漿束，藉由改變外電極寬度及內外電極間距，觀察電漿束內活性物質生成之濃度改變，了解電極結構對電漿束的影響，及其實際殺菌效率，以增進生醫工程領域之實際應用發展。此電漿設備包含一石英管作為介電材質，石英管中固定一金屬內電極，並在石英管外壁纏繞不同寬度之鋁膠帶作為外電極。在本研究中，我們利用光譜儀器來分析電漿之後放電區域內所含的粒子物種，並搭配溫度量測進一步地得到最佳化電極配置參數。實驗結果顯示，加寬電極間距離以及外電極寬度皆會提高電漿溫度、增加消耗功率；而O/OH粒子的濃度僅受電極距離的影響；另一方面，電漿束的外觀及長度不受電極配置的影響，維持在四公分左右；而實驗所得的電漿溫度均低於40℃，皆為人體可接受的範圍。殺菌實驗顯示此設備能於15秒內有效殺死蛀牙菌S. mutans，且處理時間若延長至60秒，殺菌面積能擴大至原有的12.8倍，而改變電極配置的結果顯示電極距離對殺菌效率的影響更卓越，此趨勢與活性粒子生成濃度結果一致；而陶瓷的表面處理結果亦顯示電漿能快速增加其表面親水性，將水滴接觸角在15秒內由72降至15度。綜合殺菌及牙材表面處理之結果，顯示此電漿設備具有實際生醫應用的潛力。

The reactive radicals generated in plasma, such as OH and O, are generally regarded as the major sources for several biomedical applications, like sterilization, tooth bleaching, and tissue regeneration. In this study, we propose a simple APPJ with a steel capillary tube fixed inside a quartz tube and an aluminum ground electrode which is wrapped around the quartz tube. One can simply adjust the arrangement of outer electrodes, which changes the magnitude of electric field and length of surface charges, to obtain the optimal performance for these applications. Results show that the gas temperature, and plasma power consumption increase simultaneously with wider ground width (GW) and larger electrodes gap (G), while radical intensities (O/OH) are only consistent with gap distance; the jet length remains about 40 mm, and the temperature is below 40℃, perfectly acceptable to human body. As for sterilization experiment, cell wall destructions of S. mutans are observed via SEM after plasma exposure, and the bacteria inhibition zone depends strongly on treating time and electrode configuration. Inhibition zone can be increased by 12.8 times by increasing treatment time from 15 s to 60 s, with condition fixed at GW5G-5; and with treating time of 15 s, the killing area is enlarged by an increment of 4 times as adjusting the condition from GW15G-5 to GW15G15. Surface modification of ceramic material also shows great wettability improvement within 15 s, by 79% reduction of contact angle. Since the plasma jet can rapidly kill S. mutans and enhance the hydrophilicity on ceramic surface at the same time, we suggest APPJ a promising method for dental surgery.