Integration of a Dielectrophoretic Tapered Aluminum Microelectrode Array with a Flow Focusing Technique

Abstract

We present the integration of a flow focusing microfluidic device in a dielectrophoretic application that based on a tapered aluminum microelectrode array (TAMA). The characterization and optimization method of microfluidic geometry performs the hydrodynamic flow focusing on the channel. The sample fluids are hydrodynamically focused into the region of interest (ROI) where the dielectrophoresis force (FDEP) is dominant. The device geometry is designed using 3D CAD software and fabricated using the micro-milling process combined with soft lithography using PDMS. The flow simulation is achieved using COMSOL Multiphysics 5.5 to study the effect of the flow rate ratio between the sample fluids (Q1) and the sheath fluids (Q2) toward the width of flow focusing. Five different flow rate ratios (Q1/Q2) are recorded in this experiment, which are 0.2, 0.4, 0.6, 0.8 and 1.0. The width of flow focusing is increased linearly with the flow rate ratio (Q1/Q2) for both the simulation and the experiment. At the highest flow rate ratio (Q1/Q2 = 1), the width of flow focusing is obtained at 638.66 µm and at the lowest flow rate ratio (Q1/Q2 = 0.2), the width of flow focusing is obtained at 226.03 µm. As a result, the flow focusing effect is able to reduce the dispersion of the particles in the microelectrode from 2000 µm to 226.03 µm toward the ROI. The significance of flow focusing on the separation of particles is studied using 10 and 1 µm polystyrene beads by applying a non-uniform electrical field to the TAMA at 10 VPP, 150 kHz. Ultimately, we are able to manipulate the trajectories of two different types of particles in the channel. For further validation, the focusing of 3.2 µm polystyrene beads within the dominant FDEP results in an enhanced manipulation efficiency from 20% to 80% in the ROI.

A dielectrophoresis proof of concept of polystyrene particles and in‐vitro human epidermal keratinocytes migration for wound rejuvenation

“…In this study, the tapered aluminium microelectrode array (TAMA) geometry is used. A two‐dimensional model of the simplified TAMA geometry that was used in the FEM analysis 39,40 . The commercial FEM package was used to execute this numerical model COMSOL Multiphysics 5.6, http://www.comsol.com made available in November 11, 2020 (COMSOL Inc., Burlington, MA, USA).…”

“…A two-dimensional model of the simplified TAMA geometry that was used in the FEM analysis. 39,40 The commercial FEM package was used to execute this numerical model COMSOL Multiphysics 5.6, www.comsol.com made available in November 11, 2020 (COMSOL Inc., Burlington, MA, USA). The dielectric properties of the particle/cell are initially incorporated into the model.…”

A correlation of conductivity medium and bioparticle viability on dielectrophoresis‐based biomedical applications

“…Metals, for instance, gold (Au), silver (Ag), chromium (Cr), platinum (Pt), and titanium (Ti), are commonly used to implement electrode geometries [60][61][62]. Which includes planar [63,64], interdigitated [65,66], quadrupole [3], tapered [45,[67][68][69][70][71][72][73], rectangular [74], curved [75], and spiral electrodes [4,35]. Joule heating, fouling, and electrochemical reactions that primarily result from electrode disintegration produce toxic species are the main limitations of eDEP [76].…”

Omnidirectional Manipulation of Microparticles on a Platform Subjected to Circular Motion Applying Dynamic Dry Friction Control

“…The manipulation of microparticles is very important for many disciplines and sectors, such as micromachine technology, biotechnology, cell biology, material processing, semiconductor industries, and neuroscience [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Handling, transportation, and manipulation of microparticles or bulk and granular materials can be implemented by various methods and approaches that can generally be divided into two types: prehensile and non-prehensile.…”