Optoelectronic manipulation of microparticles using double photoconductive layers on a liquid crystal display

Abstract

This paper describes a novel platform for the optoelectronic manipulation of microparticles termed a three-dimensional optoelectronic tweezers (3D OET) and composed of double photoconductive layers. The 3D OET has been successfully utilized for focusing polystyrene beads onto the middle of a liquid chamber using negative dielectrophoresis (DEP). As a result, the microparticles are segregated from the device surface, thus preventing the adsorption by non-specific surface-particle interactions which were shown to occur in a typical OET device. We have compared the performance of 3D OET to typical OET based on a liquid crystal display (LCD) with several parameters, such as LCD image patterns, bead sizes and processing times. The 3D OET has a higher particle trapping efficiency and less particle adsorption rate than typical OET. Our novel platform would be a useful tool for manipulating microparticles, including live cells and polymer beads.