Self-powered microfluidic pump using evaporation from diatom biosilica thin films
Self-powered microfluidic pump using evaporation from diatom biosilica thin films
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DOI：
10.1007/s10404-020-02343-5
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发表时间：
2020-04
影响因子：
2.8
通讯作者：
H. Jarrett;Micah Wade;Joseph A. Kraai;G. Rorrer;Alan X. Wang;Hua 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;Hua Tan
近年来，研究人员已经成功地将硅藻生物硅应用于分子检测平台，包括表面增强拉曼散射（Sers）光流体传感器，目前能够检测浓度低至10 - 10 M的各种生物和化学分子。本研究探讨了Sers装置的可行性，通过确定流速限制和稳定性，耦合硅藻生物二氧化硅薄膜的传感和泵送能力。在本文中，我们量化的多孔硅藻生物二氧化硅薄膜的能力，连续泵去离子（DI）水从水库通过毛细流动，利用强毛细力的多孔膜加上蒸发。我们的微流体装置由固定到水平毛细管的狭窄水平储液器组成，所述水平毛细管的端部接触硅藻生物二氧化硅膜。通过改变生物二氧化硅多孔膜的尺寸和/或温度来控制流速，所述生物二氧化硅多孔膜通过跟踪储层中的液体弯月面位移来确定，并且与修改的层流边界层模型相关联。通过在给定实验的过程中跟踪流速、接触膜的弯月面的图像分析和流动持续时间研究来观察系统稳定性。我们发现，对于未处理的去离子水，在高于40 °C的温度下，气泡开始在毛细管中形成，但脱气水在90 °C及以下的温度下保持稳定。膜的泵送能力范围为0.11至10.46微升/分钟，与理论预测相匹配，表现出稳定的流动趋势，并保持流动超过48小时。
In recent years, researchers have successfully applied diatom biosilica to molecular detection platforms including Surface-Enhanced Raman Scattering (SERS) optofluidic sensors that are currently capable of detecting a variety of biological and chemical molecules at concentrations as low as 10−10M. This study investigates the feasibility of an SERS device that couples the sensing and pumping capabilities of diatom biosilica thin films by determining flow rate limitations and stability. In this paper, we quantify the ability of porous diatom biosilica thin films to continuously pump deionized (DI) water from a reservoir via wicking flow by utilizing the strong capillary forces of the porous film coupled with evaporation. Our microfluidic device is comprised of a narrow horizontal reservoir fixed to a horizontal capillary whose end contacts a diatom biosilica film. Flow rates were controlled by altering the size and/or temperature of the biosilica porous film, determined by tracking the liquid meniscus displacement in the reservoir, and correlated with a modified laminar boundary-layer model. System stability was observed by tracking flow rates over the course of a given experiment, image analysis of the meniscus contacting the film, and a flow duration study. We found that for untreated DI water bubbles begin to form in the capillary tube at temperatures above 40 °C, but degassed water remains stable at temperatures of 90 °C and below. The pumping capabilities of the films ranged from 0.11 to 10.46 µL/min, matched theoretical predictions, demonstrated stable flow trends, and maintained flow for over 48 h.