Boldt Niklas P, Weirauch Laura, Späth Jana M, Kerst Uwe, Birkholz Mario, Baune Michael, Thewes Roland
Chair of Sensor and Actuator Systems, Faculty of EECS, TU Berlin, Berlin, Germany.
Faculty of Production Engineering, Chemical Process Engineering, University of Bremen, Bremen, Germany.
Electrophoresis. 2025 Jan;46(1-2):104-111. doi: 10.1002/elps.202400164. Epub 2024 Nov 28.
In this study, the influence of using rectangular waveforms is comprehensively investigated on the separation and sorting efficiency of dielectrophoretic (DEP) processes. Besides positive effects on DEP experiments, cases of a diminished force due to rectangular waveforms are investigated and discussed. This investigation encompasses two primary experimental setups. First, microparticle-focusing experiments are carried out using a pair of electrodes within a microfluidic channel. Second, separation experiments are performed using a macroscopic insulator-based dielectrophoretic filter. The study reveals that harmonics of rectangular signals can have a positive impact on separation or sorting efficiency when compared to sinusoidal waveforms, provided that these harmonics contribute to the overall DEP force with the same sign. This positive effect is found to depend on the ratio between the applied fundamental frequency and the cross-over frequency in the Clausius-Mossotti factor. However, violating related derived boundary conditions leads to negative effects and a decrease in the DEP net force.
在本研究中，全面研究了使用矩形波形对介电泳（DEP）过程的分离和分选效率的影响。除了对DEP实验有积极影响外，还对由于矩形波形导致力减小的情况进行了研究和讨论。该研究包括两种主要的实验装置。首先，使用微流体通道内的一对电极进行微粒聚焦实验。其次，使用基于宏观绝缘体的介电泳过滤器进行分离实验。研究表明，与正弦波形相比，矩形信号的谐波在这些谐波以相同符号对总DEP力有贡献的情况下，可对分离或分选效率产生积极影响。发现这种积极效果取决于所施加的基频与克劳修斯 - 莫索蒂因子中的交叉频率之比。然而，违反相关推导的边界条件会导致负面影响并降低DEP净力。
