Aldrich N. K. Lau

Optically Controlled Cell Discrimination and Trapping Using Optoelectronic Tweezers

Optoelectronic tweezers (OET) provide a powerful tool for the manipulation of micro- and nanoparticles. The OET device produces an optically controlled dielectrophoretic force, allowing complex dynamic manipulation patterns using light intensities up to 100 000 times lower than that of optical tweezers. Using OET, we demonstrate the separation of live and dead human B cells, and the separation of HeLa and Jurkat cells. We also present, for the first time, a modified single-sided OET device that promises to facilitate the integration of OET and microfluidics. Unlike standard OET, this single-sided OET device produces electric fields that are oriented parallel to the plane of the device. We demonstrate the manipulation of polystyrene beads using this new single-sided OET device, and discuss its capabilities

Spatial cell discrimination using optoelectronic tweezers

The difference in dielectric properties of live HeLa and Jurkat cells are used to spatially discriminate the cells using optoelectronic tweezers. Spatial discrimination is verified by fluorescent tagging of the Jurkat cells