Homogenous mixing in microfluidic devices is often required for efficient chemical and biological reactions. Passive micromixing without external energy input has attracted much research interest. We have developed a high-performance 3D micromixer over a wide range of Reynolds number (Re) and viscosity, which was fabricated in a low-cost method of 3D printing. The characterization of the 3D printer was performed by measuring the surface roughness and fabrication error. The mixing mechanism and performance of the micromixer were investigated through numerical simulations and experiments. Influences of geometry parameters, including length, rotation direction and connection angle of helical elements, were also investigated. The mixing performance of the micromixer was studied over an ultra-wide range of flow rates from 0.3 to 70 000 μL min⁻¹ (Re = 0.01–2333.3). The mixer presented an excellent mixing performance, with a mixing efficiency of more than 96.5% for water and more than 85.1% for solutions with viscosities nearly 13 times that of water. The micromixer can achieve rapid mixing with a mixing time of 883.7 μs for aqueous solutions. In addition, the high-performance micromixer was integrated into a versatile electrochemical detection platform to enhance enzyme-catalyzed reactions. The bare microelectrode array (μEA) on the detection platform has a wide linear detection range to sarcosine from 30 to 1000 μM with a limit of detection (LOD) of 9.7 μM. The highest sensitivity for sarcosine detection (281.7 μA mM⁻¹ cm⁻²) and enhancement of current response up to 57.1% were achieved on the detection platform. This work broadens the scope of micromixer applications and sheds new light on the development of high-performance micromixers.

中文翻译：

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一种低成本、高性能、宽工作范围的 3D 微混合器及其在高灵敏度生物标志物检测中的应用

有效的化学和生物反应通常需要微流体装置中的均匀混合。无外部能量输入的被动微混合引起了广泛的研究兴趣。我们开发了一种高性能的 3D 微混合器，具有广泛的雷诺数 (Re) 和粘度，采用低成本的 3D 打印方法制造。通过测量表面粗糙度和制造误差来表征 3D 打印机。通过数值模拟和实验研究了微混合器的混合机理和性能。还研究了几何参数的影响，包括螺旋元件的长度、旋转方向和连接角。在 0.3 至 70 000 μL min 的超宽流速范围内研究了微混合器的混合性能^-1 (Re = 0.01–2333.3)。该混合器呈现出优异的混合性能，对水的混合效率达到96.5%以上，对粘度接近水13倍的溶液的混合效率达到85.1%以上。微混合器可以实现快速混合，水溶液的混合时间为 883.7 μs。此外，高性能微混合器被集成到多功能电化学检测平台中，以增强酶催化反应。检测平台上的裸微电极阵列 (μEA) 对肌氨酸的线性检测范围从 30 到 1000 μM，检测限 (LOD) 为 9.7 μM。肌氨酸检测的最高灵敏度（281.7 μA mM ^-1 cm ^-2) 并在检测平台上实现了高达 57.1% 的电流响应增强。这项工作拓宽了微混合器的应用范围，并为高性能微混合器的开发提供了新的思路。