Dual vision-equipped microfluidic chip for spatiotemporal sequential pick-and-place of oocytes

Oocytes have long been used as a fundamental biological model in bioengineering research such as gene expression analysis, electrophysiological measurements, and drug screening. However, current methods mainly focus on single-microscope setups, which limits the efficient manipulation of multiple oocytes across spatially separated worksites. This study presents a dual vision-equipped microfluidic chip for the manipulation of multiple oocytes between different worksites. The microfluidic chip is equipped with two miniature cameras and then installed on a robotic manipulator. One miniature camera is used to track the position of oocytes in the microfluidic chip. The vision position of the multiple oocytes is utilized to control the flow. The results showed that multiple objects were successfully separated and released in sequence only using the hydrodynamic flow focusing effect. Moreover, a well port is designed to trap single oocytes to deal with the unseparated case of neighboring oocytes in the microchannel based on the vision information. Subsequently, the other camera is installed on the top of the tip part and utilized to detect the single object picking-placing position. Finally, we demonstrate that the dual vision-equipped microfluidic chip on-robot can pick, transport, and place multiple oocytes between different well chip areas. The proposed method has application potential in oocyte biomedical engineering.