Microalgae concentrations have been studied as an important factor to reflect water qualities. High concentration of microalgae should cause water eutrophication then cause environment pollution. However, conventional methods to monitor algal concentration in source water whose use is hampered by high-cost, complicated operation and the need of a centralized laboratory for practical samples' analysis. In order to overcome these constraints, here in this work, we developed a portable and real-time monitoring platform which consists of a microfluidic chip for algae enrichment, a portable microscopic imaging system integrated with a commercial smartphone. The chip is designed and fabricated with a multi-layer electrode structure to trap algaes via alternating current electrokinetics (ACEK) effect. A temperature dependent fully coupled numerical model is presented to calculate the ACEK flow, showing satisfied trapping performance by adjusting the applied voltage and frequency. Moreover, preliminary experiments are performed in our chip using freshwater samples, in which algae trapping behavior is visually observed and recorded by a self-designed portable microscope. Then the trapping performance of this system can be semi-quantitatively figured out by image processing. This lab-on-a-chip system shows high potential in concentrating bio-particles and developing a portable, integrated and automated system for monitoring the quality of water resources in nature. [2020-0381]

中文翻译：

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集成微平台的便携式介电泳微流控芯片用于水华监测


微藻浓度已作为反映水质的重要因素进行了研究。高浓度的微藻会造成水体富营养化，进而造成环境污染。然而，监测水源水中藻类浓度的传统方法其使用受到成本高、操作复杂以及需要集中实验室进行实际样品分析的限制。为了克服这些限制，在这项工作中，我们开发了一种便携式实时监测平台，该平台由用于藻类富集的微流控芯片、与商用智能手机集成的便携式显微成像系统组成。该芯片采用多层电极结构设计和制造，通过交流电动力学（ACEK）效应捕获藻类。提出了一个与温度相关的全耦合数值模型来计算 ACEK 流量，通过调整施加的电压和频率显示出满意的捕获性能。此外，我们的芯片利用淡水样本进行了初步实验，通过自行设计的便携式显微镜目视观察并记录藻类的捕获行为。然后可以通过图像处理半定量地计算出该系统的陷印性能。这种芯片实验室系统在浓缩生物颗粒和开发便携式、集成和自动化系统来监测自然界水资源质量方面显示出巨大的潜力。 [2020-0381]