An integrated acoustic and dielectrophoretic particle manipulation in a microfluidic device for particle wash and separation fabricated by mechanical machining

Abstract

In this study, acoustophoresis and dielectrophoresis are utilized in an integrated manner to combine the two different operations on a single polydimethylsiloxane (PDMS) chip in sequential manner, namely, particle wash (buffer exchange) and particle separation. In the washing step, particles are washed with buffer solution with low conductivity for dielectrophoretic based separation to avoid the adverse effects of Joule heating. Acoustic waves generated by piezoelectric material are utilized for washing, which creates standing waves along the whole width of the channel. Coupled electro-mechanical acoustic 3D multi-physics analysis showed that the position and orientation of the piezoelectric actuators are critical for successful operation. A unique mold is designed for the precise alignment of the piezoelectric materials and 3D side-wall electrodes for a highly reproducible fabrication. To achieve the throughput matching of acoustophoresis and dielectrophoresis in the integration, 3D side-wall electrodes are used. The integrated device is fabricated by PDMS molding. The mold of the integrated device is fabricated using high-precision mechanical machining. With a unique mold design, the placements of the two piezoelectric materials and the 3D sidewall electrodes are accomplished during the molding process. It is shown that the proposed device can handle the wash and dielectrophoretic separation successfully. V C 2016 AIP Publishing LLC.

A portable microfluidic platform for rapid determination of microbial load and somatic cell count in milk

“…The inlet and outlet wells were punched out. The PDMS piece was bonded onto a clean slide following a 50-s plasma treatment (Zeinali et al 2015;Cetin et al 2016).…”

Assessment of Lagrangian Modeling of Particle Motion in a Spiral Microchannel for Inertial Microfluidics

“…To assess the performance of the computational model, a spiral channel with an AR 9.0 was fabricated. The microfluidic device was fabricated using PDMS molding with a brass mold [ 39 ] followed by a plasma bonding on a glass slide. The fabrication of the mold was performed by a 3-axis micro-machining center (PROINO Z3X Micro Maker, Mikro Protez Ltd.…”

“…Once correlations for inertial forces are obtained, the Lagrangian discrete phase model can be utilized. Lagrangian-based modeling is very fast and suitable for Monte Carlo-type simulations where statistical variation of inlet locations, size and properties of particles can be implemented to assess the performance of the process [ 38 , 39 ]. Lagrangian-based modeling has also been implemented for inertial microfluidics using the correlations available for the inertial forces in the literature [ 19 , 20 , 37 , 40 , 41 ].…”

Electrokinetic Phenomena in Pencil Lead-Based Microfluidics

“…Electrokinetic transport processes such as electroosmosis, induced charge electroosmosis (ICEO) and dielectrophoresis (DEP) using electric fields have become important techniques to manipulate fluids and particles in various microfluidic applications [ 3 , 4 ]. ICEO flow is a nonlinear electro-osmotic flow and typically occurs around a conductive surface or floating electrode under an external direct current (DC) or low frequency alternating current (AC) electric field [ 5 ].…”