生醫應用上之蠕動式微幫浦性能探討

Abstract

本論文描述利用微機電系統技術的壓電無閥門蠕動式微型幫浦的設計、製程與應用。微幫浦驅動原理在於PZT受到驅動訊號使得致動薄膜做往覆週期的運動。如此的裝置就如同活塞提供動力驅動微升等級的流體，如此可利用到許多生醫應用上的實驗室晶片。因此，本論文便是針對微幫浦的性能分析而探討，主要可分成兩部分。 首先，我們關注的是系統與週遭環境對輸出共振頻率的影響。為提高蠕動式微型幫浦的輸出能力，從理論上分析了負載流體對致動薄膜動態特性的影響規律。除了流體的密度以及黏滯性會對附加質量及附加阻尼造成影響外，流室深度以及驅動相位亦會影響致動薄膜動態特性，造成頻率位移現象。其次，流體的傳輸能力與電路的設計是具有緊密的連結。因此藉由適當電路設計的改良能有效提升傳輸流量 1.9~2.8 倍。

A valveless peristaltic micropump based on piezoelectric actuation was designed and fabricated. The pump diaphragms are excited by applying pulse signal voltages to three lead zirconate titanate (PZT) disks on glass diaphragm. Such diaphragm structure acts as a “piston” to provide power for the handling of microliter-scaled fluid volumes desired in many lab-on-a-chip chemical and biomedical applications. A high-performance micropump was investigated for this purpose. The paper contains mainly two parts as follows. First, we are concerned with the interactions between a system and its environment for the influence on output resonance frequency. Analytical results for frequency shift was presented to show that not only does the added mass and added damping depend on both the fluid density and viscosity, the chamber height and actuated signal are as well. Second, the driving circuit can be closely linked with the fluid transport related to the pump performance. Therefore, the improvement design for driving circuit can enhance pump flow rate performance up to 1.9~2.8 times.