生醫用微型壓電泵之研究

Abstract

微型流體系統廣泛應用於化學和生物醫學領域，在這方面已經進行了廣泛的研究。本論文透過三個研究成果，提出了微型流體系統的發展基礎。首先，提出了一種新型的壓電驅動微型泵。使用0.2 mm厚的壓電層和0.25 mm厚的黃銅板的壓電致動器以及0.05 mm厚的嵌入式導流肋結構以提高泵浦效率。透過壓電致動器以及泵浦腔體內部的導流結構組合，在低頻範圍內實現了高流量。對於水和仿真血液模擬流體，分別達到196mL/min和141 mL/min的高流速。 其次，結合了雙簧壓電致動器和分離式泵浦腔體，發展了無閥式壓電微型泵。其中所提出的分離腔體結構可避免重複使用泵浦所引起的交叉污染問題。在所提出的微型泵浦中，藉由圓形雙簧壓電致動器連接傳力柱和覆蓋腔體的PET薄膜間接驅動，並針對所提出的分離式腔體進行效率研究，包括薄膜厚度，腔體直徑和柱腔比等幾個參數。所提出的具有10 mm腔體直徑和0.9的柱腔比的泵浦結構，實現9.1mL / min的最大流速。 第三項成果是將兩個微型壓電泵浦和一新穎的混合腔體結構結合的微型混合系統。混合腔體是為了便利組裝和一次性使用而設計。藉由微型壓電泵輸送的兩種不同染劑的液體注入至混合腔體進行混合。在12 mL/min的流量下，針對不同的混合腔體結構進行了模擬和實驗。在混合腔體內實現了優異的混合，其實驗結果與模擬預測結果一致。根據結果，討論了混合系統的流道設計以及混合特性和效率。 所提出的三種關鍵流體裝置的成功實驗結果為未來設計和實現用於商業生物醫學應用的微型流體系統提供了良好的支持。

Miniature fluidic system is widely used in chemical and bio-medical fields, and in this regard, extensive researches have been conducted in related applications. This dissertation has presented the development of the basis of a miniature fluidic system through three achievements. First, a novel piezoelectric-driven miniature pump was proposed. It achieved high flow rate at low frequency range through a combination of piezoelectric-actuator and pumping chamber with internal flow- guiding structures. High flow rates of up to 196 mL/min and 141 mL/min were achieved for water and blood mimicking fluid, respectively. It was achieved by using a piezoelectric actuator with a 0.2 mm thick piezoelectric layer and a 0.25 mm thick brass plate, and a pumping chamber with 0.05 mm thick embedded flow-guiding rib structures for pumping efficiency improvement. Second, a valve-less piezoelectric miniature pump was developed by combining a bimorph piezoelectric actuator and a separable, disposable pumping chamber. The cross-contamination issues caused by repeated uses of pumps can be easily avoided with the proposed separable chamber structure, making the pump ideal for biological fluid transmission process. The pumping in the proposed miniature pump was indirectly driven by a circular piezoelectric bimorph actuator through a pillar structure that connects the actuator and a PET diaphragm covering the pumping chamber. The pumping efficiency of the proposed miniature pump was investigated with respect to several parameters including the diaphragm thickness, the chamber diameter and the pillar-to-chamber ratio. A maximum flow rate of 9.1 mL/min was achieved by using the proposed pump structure with 10 mm chamber diameter and a pillar-to-chamber ratio of 0.9. The third achievement was a miniature mixing system combining two miniature piezoelectric pumps and a novel mixing chamber structure. The proposed mixing chamber was specifically designed for easy assembly and disposable usage. Mixing was carried out by injecting water with two distinct color settings from the piezoelectric pumps into the mixing chamber. At 12 mL/min pumping flow rate, simulations and experiments were conducted for different mixing chamber structures. Excellent mixing was achieved and observed within the mixing chamber and experiment results show good agreement with the simulation predictions. Based on the results, the mixing characteristics and efficiency were discussed for optimal mixing system design. The successful experimental results of the proposed three key fluidic devices give good support to the future design and realization of a miniature fluidic system for commercial biomedical applications.