Automatic and precise fluid manipulation is essential in microfluidic applications. Microfluidic metering, in particular, plays a critical role in achieving the multiplexity of assays, reaction consistency, quantitative analysis, and the scalability of microfluidic operations. However, existing fluid metering techniques often face limitations, such as high complexity, high cost, reliance on external accessories, and lack of precision, which have restricted their use in multiplexed and quantitative analysis, especially in portable applications. In this study, we present a novel portable gravity-driven metering system designed for automated multiplexed fluid metering, multistep fluid control, and multi-chamber signal readout. Our metering chip utilizes gravitational force to dispense sample liquids, allowing for versatile and precise metering. Guided by a series of numerical simulations, we optimized the design of our metering chip to achieve rapid and accurate liquid metering. Furthermore, thermal control valves were employed to facilitate automated and programmable fluid transfer, eliminating the need for external equipment. To enhance user experience, we developed a smartphone-assisted readout pod for seamless integration with the metering chip. We validated the efficacy of our platform through a proof-of-concept multiplexed analysis of urinary biomarkers, demonstrating high sensitivity, specificity, and absolute quantification capabilities. Our gravity-driven metering system shows significant potential for applications in multiplexed diagnostics, drug screening, and material synthesis, effectively addressing critical needs in fluid manipulation and analysis.

中文翻译：

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重力驱动的微流体计量系统，用于多重生物测定的自动化。


自动和精确的流体操作在微流体应用中至关重要。特别是微流体计量，在实现分析的多重性、反应一致性、定量分析和微流体操作的可扩展性方面发挥着关键作用。然而，现有的流体计量技术往往面临局限性，例如高复杂性、高成本、依赖外部附件和缺乏精度，这限制了它们在多重和定量分析中的应用，尤其是在便携式应用中。在本研究中，我们提出了一种新型便携式重力驱动计量系统，该系统设计用于自动多路复用流体计量、多级流体控制和多腔室信号读出。我们的计量芯片利用重力来分配样品液体，从而实现多功能和精确的计量。在一系列数值模拟的指导下，我们优化了计量芯片的设计，实现了快速准确的液体计量。此外，采用热控制阀来促进自动化和可编程的流体传输，无需外部设备。为了提升用户体验，我们开发了一个智能手机辅助读出舱，用于与计量芯片无缝集成。我们通过对尿液生物标志物进行概念验证多重分析来验证我们平台的有效性，展示了高灵敏度、特异性和绝对定量能力。我们的重力驱动计量系统在多重诊断、药物筛选和材料合成方面显示出巨大的应用潜力，可有效满足流体操作和分析的关键需求。