Despite advances in measuring fluid viscosity, we still lack portable viscometers to analyze shear rate-varying fluid characteristics in the form of open-source hardware that non-expert users can easily make and use. We present a hand-held, automatic capillary viscometer, termed "Viscopette", which can be fabricated simply by assembling globally available mechanical (a stepper motor and an inline pressure sensor), fluidic (a positive-displacement pipette and a cut tubing piece), electronic (an Arduino board) parts in a 3D-printed housing. The Viscopette is specifically designed to improve user experience by adopting how to use commercial micropipettes, and fits within 7.3 cm × 7.3 cm × 38.8 cm (without the cut tubing piece) with an overall weight of 437 g for portable use. By exploiting the high level of controllability of the open-source microcontroller, the Viscopettes enables time-varying shear-rate (or flow-rate) control for viscosity analysis, and simple viscosity measurement by calculating the ratio of a pressure value measured using the inline pressure sensor and a set flow-rate condition. With the advantages of ease-of-use, portability, and shear-rate controllability, we demonstrate the Viscopette's ability to accurately analyze Newtonian and non-Newtonian fluids. Our method addresses the unmet need in portable, high-performance viscometers suitable for use as an open-source equipment, which can facilitate on-site, accurate viscosity analysis even by non-expert users.

尽管在测量流体粘度方面取得了进步，但我们仍然缺乏便携式粘度计，以非硬件用户可以轻松制造和使用的开源硬件的形式来分析剪切速率变化的流体特性。我们提供了一种手持式自动毛细管粘度计，称为“ Viscopette”，可以通过组装全球通用的机械装置（步进电机和在线压力传感器），流体装置（容积式移液器和切开的管件）来简单地制造，电子（Arduino板）零件放在3D打印的外壳中。Viscopette是专门设计用来通过采用商用微量移液器来改善用户体验的，适用于7.3 cm×7.3 cm×38.8 cm（不带切开的管件）的重量，总重量为437 g，便于携带。通过利用开源微控制器的高度可控性，Viscopettes可以进行随时间变化的剪切速率（或流速）控制以进行粘度分析，并通过计算使用在线测量的压力值的比率来进行简单的粘度测量压力传感器和设定的流量条件。凭借易用性，便携性和剪切速率可控性的优势，我们证明了Viscopette能够准确分析牛顿流体和非牛顿流体的能力。我们的方法解决了便携式高性能粘度计（适合用作开源设备）中未满足的需求的问题，即使非专业用户也可以方便地进行精确的粘度现场分析。通过计算使用在线压力传感器测得的压力值与设定的流量条件之比，可以简便地进行粘度测量。凭借易用性，便携性和剪切速率可控性的优势，我们证明了Viscopette能够准确分析牛顿流体和非牛顿流体的能力。我们的方法解决了便携式高性能粘度计（适合用作开源设备）中未满足的需求的问题，即使非专业用户也可以方便地进行精确的粘度现场分析。通过计算使用在线压力传感器测得的压力值与设定的流量条件之比，可以进行简单的粘度测量。凭借易用性，便携性和剪切速率可控性的优势，我们证明了Viscopette能够准确分析牛顿流体和非牛顿流体的能力。我们的方法解决了便携式高性能粘度计（适合用作开源设备）中未满足的需求的问题，即使非专业用户也可以方便地进行精确的粘度现场分析。