Evaporation-Based Microfluidic Pump Using Super-Hydrophilic Diatom Biosilica Thin Films
Evaporation-Based Microfluidic Pump Using Super-Hydrophilic Diatom Biosilica Thin Films
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DOI：
10.1115/ht2019-3502
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
H. Jarrett;Micah Wade;Joseph A. Kraai;G. Rorrer;Alan X. Wang;H. Tan
中科院分区：
文献类型：
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作者：
H. Jarrett;Micah Wade;Joseph A. Kraai;G. Rorrer;Alan X. Wang;H. Tan
硅藻是一组单细胞光合藻类，它们利用生物化学途径生物矿化和自组装三维光子晶体，具有独特的光子和微纳流体特性。近年来，硅藻生物硅已被用于基于表面增强拉曼散射（Sers）的光流体传感器，用于检测各种化学和生物分子。本文提出了一种利用超亲水性硅藻薄膜来开发微流控泵系统的研究。开发这种系统的愿望源于创建低成本、自供电的微流体泵送系统的需求，该微流体泵送系统可以在延长的时间段内维持连续流动。硅藻生物硅不仅作为流动背后的驱动力，而且还作为超灵敏的Sers基底，允许对各种分子进行痕量检测。将液体从储液器抽至直接位于硅藻膜上方的150μm内径毛细管的尖端。当液体最初通过毛细管从储液器被吸引到硅藻膜时，使用薄且长的水平储液器来防止硅藻膜上的溢流。在部分填充的储液器排空之前，从水平储液器保持弯月面从毛细管到膜的连接持续20小时32分钟的记录时间。在63°F的温度和45%的相对湿度下，对于49 mm 2、25 mm 2和9mm 2的正方形生物二氧化硅薄膜，分别实现了0.38、0.22和0.16μL/min的流速。为49 mm 2基底引入温度控制系统，在72、77、86和95°F和21%相对湿度下分别观察到0.60、0.82、0.93和1.15μL/min的流速。将进行更多的测试和分析，以测试所提出的自供电微流体系统的操作限制。
Diatoms are a group of single-celled photosynthetic algae that use biochemical pathways to bio-mineralize and self-assemble three-dimensional photonic crystals with unique photonic and micro- & nano-fluidic properties. In recent years, diatom biosilica has been used in surface-enhanced Raman scattering (SERS) based optofluidic sensors for detection of a variety of chemical and biological molecules. In this paper, we present a study to develop a microfluidic pumping system using super-hydrophilic diatom thin films. The desire to develop such a system stems from the requirement to create a low-cost, self-powered microfluidic pumping system that can sustain a continuous flow over an extended period of time. The diatom biosilica acts not only as the driving force behind the flow, but also serves as ultra-sensitive SERS substrates that allows for trace detection of various molecules. Liquid is drawn from a reservoir to the tip of a 150μm inner diameter capillary tube positioned directly over the diatom film. A thin and long horizontal reservoir is used to prevent flooding on the diatom film when the liquid is initially drawn to the diatom film through a capillary tube from the reservoir. The connection of the meniscus from the capillary to the film was maintained from a horizontal reservoir for a recorded time of 20 hours and 32 minutes before the partially filled reservoir emptied. Flow rates of 0.38, 0.22 and 0.16μL/min were achieved for square biosilica thin films of 49mm2, 25mm2, and 9mm2 at a temperature of 63°F and 45% relative humidity respectively. A temperature-controlled system was introduced for the 49mm2 substrate and flow rates of 0.60, 0.82, 0.93, and 1.15μL/min were observed at 72, 77, 86, and 95°F at 21% relative humidity respectively. More testing and analysis will be performed to test the operation limits of the proposed self-powered microfluidic system.