We introduce a method for trapping and arranging microparticles in arbitrary two-dimensional patterns with high flexibility. For this purpose, optoelectronic tweezers based on lithium niobate as photoconductor are used to create virtual electrodes through modulated illumination. The evolving field gradients arrange microparticles due to dielectrophoretic (DEP) forces and enable an all-optical approach for DEP. In order to increase flexibility further, we investigate multiplexed electrode structures for in situ reconfiguration of particle arrangements. Using the all-optical erasure of previously written virtual electrodes, we demonstrate electrode switching and sequential particle trapping in a microchannel for microfluidic applications.
© 2012 Optical Society of America
Original Manuscript: April 5, 2012
Revised Manuscript: July 2, 2012
Manuscript Accepted: August 1, 2012
Published: September 5, 2012
Vol. 7, Iss. 11 Virtual Journal for Biomedical Optics
Stefan Glaesener, Michael Esseling, and Cornelia Denz, "Multiplexing and switching of virtual electrodes in optoelectronic tweezers based on lithium niobate," Opt. Lett. 37, 3744-3746 (2012)