In this study, we demonstrate the use of cyclical low frequency signals with insulator-based dielectrophoresis (iDEP) devices for the separation of particles of similar characteristics and an experimental method for estimating particle DEP mobilities. A custom signal designer program was created using Matlab® and COMSOL Multiphysics® for the identification of specific low frequency signals aimed at separating particle mixtures by exploiting slight differences in surface charge (particle zeta potential) or particle size. For the separation by surface charge, a mixture of two types of 10 μm particles was analyzed and effectively separated employing both a custom step signal and a sawtooth left signal. Notably, these particles had the same shape, size, and surface functionalization as well as were made from the same substrate material. For the separation by size, a sample containing 2 μm and 5 μm particles was successfully separated using a custom step signal; these particles had the same shape, surface functionalization, were made from the same substrate materials, and had only a small difference in zeta potential (10 mV). Additionally, an experimental technique was developed to estimate the dielectrophoretic mobility of each particle type; this information was then utilized by the signal designer program. The technique developed in this study is readily applicable for designing signals capable of separating micron-sized particles of similar characteristics, such as microorganisms, where slight differences in cell size and the shape of surface charge could be effectively exploited. These findings open the possibility for applications in microbial screening using iDEP devices.

中文翻译：

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用于微调基于绝缘体的介电泳分离的低频循环电位。

在这项研究中，我们展示了使用周期性低频信号和基于绝缘体的介电电泳 (iDEP) 装置来分离具有相似特性的颗粒，以及估计颗粒 DEP 迁移率的实验方法。使用 Matlab® 和 COMSOL Multiphysics® 创建了一个定制信号设计器程序，用于识别特定的低频信号，旨在通过利用表面电荷（颗粒 zeta 电位）或颗粒尺寸的微小差异来分离颗粒混合物。对于通过表面电荷的分离，分析了两种类型的 10 μm 颗粒的混合物，并使用自定义阶跃信号和锯齿左信号进行有效分离。值得注意的是，这些颗粒具有相同的形状、尺寸和表面功能化，并且由相同的基材材料制成。对于按尺寸分离，使用自定义阶跃信号成功分离了包含 2 μm 和 5 μm 颗粒的样品；这些颗粒具有相同的形状、表面功能化、由相同的基底材料制成，并且 zeta 电位仅有很小的差异（10 mV）。此外，还开发了一种实验技术来估计每种颗粒类型的介电泳迁移率；然后该信息被信号设计器程序利用。这项研究中开发的技术很容易适用于设计能够分离具有相似特征的微米级颗粒的信号，例如微生物，其中细胞尺寸和表面电荷形状的细微差异可以被有效地利用。这些发现为使用 iDEP 设备进行微生物筛查的应用提供了可能性。