AC electrokinetic biased deterministic lateral displacement for tunable particle separation. Issue 8 (26th March 2019)

• Record Type: Journal Article
• Authors: Calero, Victor; Garcia-Sanchez, Pablo; Honrado, Carlos; Ramos, Antonio; Morgan, Hywel
• Is Part Of: Lab on a chip. Volume 19:Issue 8(2019)
• Page Start: 1386
• Page End: 1396
• Publication Date: 2019-03-26
• Subjects: Miniature electronic equipment -- Periodicals; Combinatorial chemistry -- Periodicals; Biotechnology -- Periodicals; 543.0813
• DOI: 10.1039/c8lc01416g
• Languages: English
• ISSNs: 1473-0197

Abstract

Abstract : We describe a novel particle separation technique that combines deterministic lateral displacement (DLD) with orthogonal electrokinetic forces to separate particles below the critical diameter. Abstract : We describe a novel particle separation technique that combines deterministic lateral displacement (DLD) with orthogonal electrokinetic forces. DLD is a microfluidic technique for continuous flow particle separation based on size. We describe new tunable devices that use a combination of AC electric fields with DLD to separate particles below the critical diameter. Planar electrodes were integrated into a classical DLD device to produce a force orthogonal to the fluid flow direction. Experiments with 3.0 μm, 1.0 μm and 500 nm diameter microspheres show that at low frequencies (up to 500 Hz) particles oscillate in the direction of the field due to electrophoretic (EP)/electroosmotic (EO) forces. As the frequency of the field increases, the amplitude of these oscillations vanishes and, eventually dielectrophoresis (DEP) becomes the dominant electrokinetic force on the particles (DEP arises from electric field inhomogeneities caused by the presence of the DLD posts). Both mechanisms alter the paths of the particles inside the DLD devices leading to enhanced sorting of particles below the critical diameter of the device.