Technologies that can detect and characterize particulates in liquids have applications in health, food, and environmental monitoring. Simply counting the numbers of cells or particles is not sufficient for most applications; other physical properties must also be measured. Typically, it is necessary to compromise between the speed of a sensor and its chemical and biological specificity. Here, we present a low-cost and high-throughput multiuse counter that classifies a particle’s size, concentration, and shape. We also report how the porosity/conductivity or the particle can influence the signal. Using an additive manufacturing process, we have assembled a reusable flow resistive pulse sensor capable of being tuned in real time to measure particles from 2 to 30 μm across a range of salt concentrations, i.e., 2.5 × 10^–4 to 0.1 M. The device remains stable for several days with repeat measurements. We demonstrate its use for characterizing algae with spherical and rod structures as well as microplastics shed from tea bags. We present a methodology that results in a specific signal for microplastics, namely, a conductive pulse, in contrast to particles with smooth surfaces such as calibration particles or algae, allowing the presence of microplastics to be easily confirmed and quantified. In addition, the shapes of the signal and of the particle are correlated, giving an extra physical property to characterize suspended particulates. The technology can rapidly screen volumes of liquid, 1 mL/min, for the presence of microplastics and algae.

中文翻译：

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可调谐的三维印刷微流阻脉冲传感器，用于表征藻类和微塑料。

可以检测和表征液体中微粒的技术已应用于健康，食品和环境监测。对于大多数应用而言，仅对细胞或颗粒的数量进行计数是不够的。其他物理性质也必须测量。通常，有必要在传感器的速度及其化学和生物学特异性之间折衷。在这里，我们提供了一种低成本，高通量的多用途计数器，该计数器可对粒子的大小，浓度和形状进行分类。我们还报告了孔隙率/电导率或颗粒如何影响信号。通过增材制造工艺，我们组装了可重复使用的流阻脉冲传感器，该传感器能够进行实时调整，以测量各种盐浓度（即2.5×10 ^–4）中2至30μm的颗粒到0.1M。通过反复测量，该设备可保持稳定几天。我们展示了其用于表征球形，杆状结构藻类以及从茶袋中脱落的微塑料的特性。我们提出了一种方法，与具有光滑表面的颗粒（例如校准颗粒或藻类）相反，该方法可导致产生针对微塑料的特定信号，即导电脉冲，从而可以轻松确认和量化微塑料的存在。此外，信号的形状与粒子的形状相关，从而提供了额外的物理特性来表征悬浮颗粒。该技术可以快速筛查液体体积（1 mL / min）是否存在微塑料和藻类。