微流道液體流動產生之能量探討

Abstract

能量的搜集這個主題多年來一直被視為是很重要且廣為流傳的全球議題。隨著捕獲以及搜集再生能源的需求提升，各種不同搜集能量的方法逐漸地被人們發掘。在本篇研究中，展示了一種利用微流道中水流產生奈米級能量的方法，也就是將微流道裡流體的動能轉換成電能的可能性。我們發現影響產生電流大小的因素可能與溶液中的奈米氣泡、液體流量、電極距離以及水溶液中pH值有關。實驗用的試片是由金電極以及微流道所組成，在實驗量測的部分，我們將流速設定在200 ul/min。根據實驗結果，由水流產生之電流訊號與電極距離以及流速皆成正相關。而電極距離越遠（0.5 cm-3 cm），輸出電流就會越大（0.3 nA-0.7 nA）。除此之外，我們也針對pH值（pH = 4-11）做了一系列的測試。根據實驗結果，我們發現pH值越高的水溶液會有較高的電流訊號。 綜合來說，這項實驗展示出其產生能量的發展潛力，它能使用在不同的水環境(例如雨水，河流，海洋等等)或者是流動的水當中，並能自動產生電流。除此之外，這項實驗也有機會可以與環境監控的應用相結合。 關鍵

Energy harvesting is one of the most popular and important global issues for years. Through capturing or storing renewable energy, different energy-harvesting methods developed to provide additional power sources. In this work, a method to detect nano-scale energy by microfluidic flow was presented. Transferring microfluidic dynamic energy into electrical energy, we investigated the relationship between the extracted electrical current versus flow rate, different electrode distances and the pH of an aqueous solution. Besides, we figured out how nanobubbles in the solution affect the experiment. The device was designed and implemented in a microfluidic channel with a gold-electrode grating. In the experimental testing, the flow rate was 200 μL/min. Based on the experimental results, the extracted output current was proportional to the electrode distance. The longer the distance (from 0.5 to 3 cm) was, the higher the output current (from 0.3 to 0.7 nA) was obtained. In addition to the electrode-distance examinations, different aqueous solution with different pH value (from 4 to 11) were also investigated. According to the experimental results, we can extract more electrical current (about 0.5 ~ 0.9 nA) with higher pH solution. In summary, this work demonstrated a potential method for energy harvesting. It could be used in different aqueous environment (ex. rain, river, marine etc.) or running water to generate current autonomously. This could be further integrated with applications of environmental monitoring.