Abstract
The concept of the blood capillary construction system is based on three modules: optical tweezers, laser guidance and the fabrication of micro channels. Inside of micro channels can be divided into three parts, capillary construction area, main channel and sub channels. The working process of the system is as follows. First, the endothelial cells were stored in a syringe and pumped into main channel. With computational fluid dynamics simulation, the geometry of micro channels was designed to allow sufficient nutrition entering the constructive region so as to keep the cell vitality but would not let the flow disturb the process. Second, the cells were guided into sub channel, lined up and flow through the channel toward construction area by laser guidance. Finally, optical tweezers trapped cells at the end of the sub channel and put them at the proper place to form a piece of blood capillary. Optical tweezers were driven by tilting the mirror. Parameters calculated from the thin-lens formula were used as initial conditions and then optimized by optics simulation software. After optimization, the working range of the optical tweezers could cover 70% field of view of the microscope objective. For a N.A.=1.25 oil immersion-type microscope objective, the working area is a circle which diameter of 70 ~ 80um