以放射光譜法應用於氣體分析之微氣泡與微電漿操控

Abstract

本研究利用介電泳機制，於晶片上進行傳送及分割微氣泡等數位微流體功能，藉由施加崩潰電壓於待測氣泡使之產生電漿，且電漿氣泡之操控亦實現於本晶片中。同時利用電漿態下原子激發所致的放射光譜進行分析，藉由光譜特徵峰的辨識，可推測氣泡內容物的成分。本研究測試空氣、氦氣、氬氣、氬氣與甲烷混合氣體及氦氬混合氣體作為電漿氣體，於微氣泡中點燃為電漿態並量測其放射光譜，得到初步氣體定性分析結果。 本晶片並具有自動裝載氣體樣本、產生氣泡、傳送、混合、多餘樣本排除及氣泡切割等自動化檢驗過程，達到可調控氣泡濃度檢測系統，達成氣體定性與定量分析目的，並將串聯上述電漿氣泡的操控，達成一個電場操控可移動式電漿氣泡檢測平台。

For the first time, we demonstrate the manipulations of microbubble and excitation of microplasma within a 200 nL microbubble in an inert oil environment using dielectrophoresis (DEP). Microbubble generation, transportation, and mixing were examined to prepare microbubbles with tunable gas compositions further analyzed by optical emission spectrum (OES) of the excited and DEP-driven microplasma from the prepared 200 nL microbubble. Here, microbubbles containing air, helium, argon, methane and their mixtures were ignited to the plasma state on one of the electrodes where a breakdown voltage applied. Characteristic peaks of helium, argon, methane and the mixtures were found and analyzed. Furthermore, bubble plasma was ignited by applying an appropriate breakdown voltage ranging from 400 VRMS to 800 VRMS with the frequencies of 1.5 kHz to 2.4 kHz.