title: Two-dimensional dielectrophoretic particle trapping in a hybrid crystal/PDMS-system.
abstract: Dielectrophoretic forces originating from highly modulated electric fields can be used to trap particles on surfaces. An all-optical way to induce such fields is the use of a photorefractive material, where the fields that modulate the refractive index are present at the surface. We present a method for two-dimensional particle alignment on an optically structured photorefractive lithium niobate crystal. The structuring is done using an amplitude-modulating spatial light modulator and laser illumination. We demonstrate trapping of uncharged graphite particles in periodic and arbitrary patterns and provide a discussion of the limitations and the necessary boundary conditions for maximum trapping efficiency. The photorefractive crystal is utilized as bottom part of a PDMS channel in order to demonstrate two-dimensional dielectrophoretic trapping in a microfluidic system.
authors: Institute for Applied Physics, Westfälische Wilhelms-Universität, Corrensstrasse 2/4, 48149 Münster, Germany. michael.esseling@uni-muenster.de
authors: Michael
authors: M
authors: Esseling
authors: Frank
authors: F
authors: Holtmann
authors: Mike
authors: M
authors: Woerdemann
authors: Cornelia
authors: C
authors: Denz
mesh_terms: D003460:Crystallization; D004560:Electricity; D004867:Equipment Design; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D007834:Lasers; D008027:Light; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D044085:Microfluidics / Q000295:instrumentation*