Cell Focusing and Rotation by a Planar Optoelectronic Tweezers

Optoelectronic tweezers (OETs) based on dielectrophoresis (DEP) force is a valuable tool for the manipulation of particles and cells. However, DEP-based methods that can measure the electrical parameters are always preformed on static metal electrode DEP systems. Here, we present a partitioned single-sided OET chip that combines an OET system and microfluidic channel. Unlike classical sandwich-structure OET chip, the single-sided chip is close to the metal electrode DEP system but can switch functions easily. Numerical simulations are studied to analyze the electric field on a microfluidic chip and provide data for characterizing cell electric properties. The focusing and electro-rotation are successfully realized by partitioned multi-signal OET system. By analyzing the rotation speed, some specific electric parameters of Raw cells are characterized. The work has laid a foundation for OET-based single-sided chip fabrication and experiment validation.