Optical tweezers have been widely used to manipulate biological cells and particles since it was demonstrated by Ashkin in 1986. However, optical manipulation using direct optical force requires tight optical focusing and is only availabe in small area. Here, we proposed a novel mechanism which enables optical manipulation using optical power 5 orders of magnitude less than that of conventional optical tweezers. This mechanism is realied by inducing optically defined virtual electrodes on semiconductive thin films. This induced virtual electrodes create highly non-uniform electric field patterns in the liquid medium to control the particle motion through dielectrophoretic forces. We call this mechanism optoelectronic tweezers (OET). The goal of OET is to develop tool that allows massively parallel manipulating micro- and nano- objects with light.
Project end date: 02/07/06