Isomotive dielectrophoresis for parallel analysis of individual particles

Abstract

Two dielectrophoresis systems are introduced where the induced dielectrophoretic force is constant throughout the experimental region, resulting in uniform (isomotive) microparticle translation. Isomotive dielectrophoresis (isoDEP) is accomplished through a unique geometry where the gradient of the field-squared (∇Erms2) is constant, a characteristic that is otherwise highly nonuniform in traditional DEP platforms. The governing isoDEP equations were derived herein and applied to two different isoDEP prototypes: (i) one fabricated from deep reactive ion etching (DRIE) of a conductive silicon wafer (1-10 Ω-cm) whose patterned features served as electrodes and microchannel sidewalls simultaneously; (ii) a second where the electric field is applied lengthwise through a PDMS microchannel whose geometry follows a specific curvature. Both positive and negative dielectrophoresis was demonstrated with the isoDEP devices using silver-coated hollow glass spheres and polystyrene particles, respectively. Particle tracking was used to compare particle trajectory with the expected dielectrophoretic response; further, particle velocity was used to measure the Clausius-Mossotti factor of individual polystyrene particles (18-24.9 μm) in both devices with a value of -0.40 ± 0.063 (n = 110) and -0.48 ± 0.055 (n = 18) for the DRIE and PDMS isoDEP platforms, respectively. The isoDEP platform is capable of analyzing multiple particles simultaneously, providing greater throughput than traditional electrorotation platforms.

On the recent developments of insulator‐based dielectrophoresis: A review

“…(B) Representation of an insulative iDEP isomotive system (isoDEP) device and two images demonstrating nDEP of polystyrene particles and pDEP of silver‐coated hollow particles, respectively. Reprinted from , copyright (2017) John Wiley and Sons.…”

“…Another interesting iDEP approach that uses a device with a geometric gradient was proposed by the Williams research group. In a recent report, this group introduced two new dielectrophoretic approaches, one based on eDEP and one based on iDEP . An illustration of the iDEP isomotive system that employs a channel with an insulative curvature is included in Fig.…”

“…Particle velocity was employed to assess the Clausius–Mossotti factor both types of particles used in this study, demonstrating the potential of iDEP platforms for particle analysis and characterization. Furthermore, an analogous iDEP isomotive system with electrodes was also created and tested with both pDEP and nDEP particle behavior .…”

Refinement of insulator-based dielectrophoresis

“…Several other works in DC and AC DEP have focused on generating a constant gradient, but these focus on the longitudinal axis or within limited zones of interaction. 59–61 In contrast, this work is aimed at minimizing inhomogeneity across the lateral dimension.…”

Insulator‐based dielectrophoresis combined with the isomotive AC electric field and applied to single cell analysis

“…Recently, isomotive DEP devices following Pohl's concept were proposed by Allen et al. . More recently, we have developed the isomotive creek‐gap electrode .…”