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1. Optimization of Mechanical Tissue Dissociation Using an Integrated Microfluidic Device for Improved Generation of Single Cells Following Digestion

   https://doi.org/10.3389/fbioe.2022.841046  

   Aliaghaei, Marzieh; Haun, Jered B. (February 2022, Frontiers in Bioengineering and Biotechnology)

   The dissociation of tissue and cell aggregates into single cells is of high interest for single cell analysis studies, primary cultures, tissue engineering, and regenerative medicine. However, current methods are slow, poorly controlled, variable, and can introduce artifacts. We previously developed a microfluidic device that contains two separate dissociation modules, a branching channel array and nylon mesh filters, which was used as a polishing step after tissue processing with a microfluidic digestion device. Here, we employed the integrated disaggregation and filtration (IDF) device as a standalone method with both cell aggregates and traditionally digested tissue to perform a well-controlled and detailed study into the effect of mechanical forces on dissociation, including modulation of flow rate, device pass number, and even the mechanism. Using a strongly cohesive cell aggregate model, we found that single cell recovery was highest using flow rates exceeding 40 ml/min and multiple passes through the filter module, either with or without the channel module. For minced and digested kidney tissue, recovery of diverse cell types was maximal using multiple passes through the channel module and only a single pass through the filter module. Notably, we found that epithelial cell recovery from the optimized IDF device alone exceeded our previous efforts, and this result was maintained after reducing digestion time to 20 min. However, endothelial cells and leukocytes still required extended digestion time for maximal recover. These findings highlight the significance of parameter optimization to achieve the highest cell yield and viability based on tissue sample size, extracellular matrix content, and strength of cell-cell interactions. 

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2. A High-Throughput Microfluidic Cell Sorter Using a Three-Dimensional Coupled Hydrodynamic-Dielectrophoretic Pre-Focusing Module

   https://doi.org/10.3390/mi14101813  

   Aghaamoo, Mohammad; Cardenas-Benitez, Braulio; Lee, Abraham P. (October 2023, Micromachines)

   Beskok, A. (Ed.)

   Dielectrophoresis (DEP) is a powerful tool for label-free sorting of cells, even those with subtle differences in morphological and dielectric properties. Nevertheless, a major limitation is that most existing DEP techniques can efficiently sort cells only at low throughputs (<1 mL h−1). Here, we demonstrate that the integration of a three-dimensional (3D) coupled hydrodynamic-DEP cell pre-focusing module upstream of the main DEP sorting region enables cell sorting with a 10-fold increase in throughput compared to conventional DEP approaches. To better understand the key principles and requirements for high-throughput cell separation, we present a comprehensive theoretical model to study the scaling of hydrodynamic and electrostatic forces on cells at high flow rate regimes. Based on the model, we show that the critical cell-to-electrode distance needs to be ≤10 µm for efficient cell sorting in our proposed microfluidic platform, especially at flow rates ≥ 1 mL h−1. Based on those findings, a computational fluid dynamics model and particle tracking analysis were developed to find optimum operation parameters (e.g., flow rate ratios and electric fields) of the coupled hydrodynamic-DEP 3D focusing module. Using these optimum parameters, we experimentally demonstrate live/dead K562 cell sorting at rates as high as 10 mL h−1 (>150,000 cells min−1) with 90% separation purity, 85% cell recovery, and no negative impact on cell viability. 

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3. Design and optimization of a fluid flow splitting device for low-flow applications

   https://doi.org/10.1016/j.slast.2025.100305  

   Yates, Alexis K; Murray, Heather N; Lippmann, Ethan S (June 2025, SLAS Technology)

   Microfluidic devices are defined by the application of fluid flow to micron-scale features. Inherent to most experiments involving microfluidic devices is the need to precisely and reproducibly control fluid flow at the microliter scale, often through multiple inlet ports on a single device. While the number of fluid channels per device varies, perfusing multiple inputs requires either the use of multiple flow controllers (often syringe or peristaltic pumps) or the ability to evenly divide fluid across outlets. Towards the latter approach, while a handful of commercial systems exist for splitting fluid flow, these set-ups require significant financial investment, multiple flow control and sensing components, and restrict the user to a predetermined perfusion control system. Simple in-line splitting devices, such a manifolds or T junctions, fail to achieve flow splitting at low flow rates often used in microfluidic systems. To increase capabilities for flow-controlled experiments, we performed experimental analyses of the physical considerations governing even flow splitting under low flow, leading to the design of a microdevice (µ-Split) that can be directly inserted into existing microfluidic set-ups. The µ-Split allows for reproducible, even flow splitting from 10 uL/min to > 2.5 mL/min. By testing multiple device geometries in combination with multiphysics simulations, we identified the design and fabrication features underlying the splitting precision achieved by the µ-Split. Overall, this work provides a useful tool to simplify microfluidic experiments that require evenly divided flow streams, while minimizing the overall device footprint. 

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4. An acoustofluidic device for efficient mixing over a wide range of flow rates

   https://doi.org/10.1039/C9LC01171D  

   Bachman, Hunter; Chen, Chuyi; Rufo, Joseph; Zhao, Shuaiguo; Yang, Shujie; Tian, Zhenhua; Nama, Nitesh; Huang, Po-Hsun; Huang, Tony Jun (March 2020, Lab on a Chip)

   Whether reagents and samples need to be combined to achieve a desired reaction, or precise concentrations of solutions need to be mixed and delivered downstream, thorough mixing remains a critical step in many microfluidics-based biological and chemical assays and analyses. To achieve complete mixing of fluids in microfluidic devices, researchers have utilized novel channel designs or active intervention to facilitate mass transport and exchange of fluids. However, many of these solutions have a major limitation: their design inherently limits their operational throughput; that is, different designs work at specific flow rates, whether that be low or high ranges, but have difficulties outside of their tailored design regimes. In this work, we present an acoustofluidic mixer that is capable of achieving efficient, thorough mixing across a broad range of flow rates (20–2000 μL min −1 ) using a single device. Our mixer combines active acoustofluidic mixing, which is responsible for mixing fluids at lower flow rates, with passive hydrodynamic mixing, which accounts for mixing fluids at higher flow rates. The mechanism, functionality, and performance of our acoustofluidic device are both numerically and experimentally validated. Additionally, the real-world potential of our device is demonstrated by synthesizing polymeric nanoparticles with comparable sizes over a two-order-of-magnitude wide range of flow rates. This device can be valuable in many biochemical, biological, and biomedical applications. For example, using our platform, one may synthesize nanoparticles/nanomaterials at lower flow rates to first identify optimal synthesis conditions without having to waste significant amounts of reagents, and then increase the flow rate to perform high-throughput synthesis using the optimal conditions, all using the same single device and maintaining performance. 

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5. Proof of Concept for Flow Through Nanoparticle Trapping Using a Dielectrophoretic Metal‐Coated Nanofiber Mat

   https://doi.org/10.1002/elps.70019  

   Mondal, Tonoy_K; Baryla, Christian; Stanley, Hannah; Williams, Stuart_J (August 2025, ELECTROPHORESIS)

   ABSTRACT While traditional dielectrophoretic methods for nanoparticle enrichment and filtration are versatile and selective, they struggle to handle higher throughput applications. To address this challenge and enhance the practical application of dielectrophoresis, we propose an innovative design for porous sandwiched nanofiber electrodes. The electrode is fabricated through a simple process involving the electrospinning of nanofibers with a diameter of 216 ± 28 nm and mat thickness of around 70 µm, followed by the deposition of a thin chromium/gold layer (approximately 140 nm thick) on both sides. This process ensures no electrical short circuit occurs between the electrodes, and it maintains a sheet resistance of 7.19 Ω/□. The resulting significant electric field gradients are capable of trapping nanoparticles with diameters of 100 nm and 40 nm. The structure's sub‐micrometer features and large active surface area allow for trapping of nanoparticles at a flow rate of 3.6 mL/h. To evaluate the effects of applied voltage and volumetric flow rate, we conducted experiments with constant voltage while varying the flow rate and constant flow rate while varying the voltage. Our findings indicate that trapping performance improves with higher AC voltage but decreases at higher flow rates. These insights are crucial for optimizing parameters for large‐scale nanoparticle enrichment and filtration. This proof‐of‐concept study for flow through dielectrophoresis of nanoparticles paves the way for a device suitable for large‐scale sample processing and higher throughput/separation efficiency in practical settings. 

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