Automatic suspended cell injection under vision and force control biomanipulation

Biological cell injection is laborious work which requires lengthy training and suffers from a low success rate. Although the development of biomanipulation technology has enabled steps towards automation of adherent cell injection, the automation of suspended cell injection remains a significant challenge. In this paper, a prototype cell injection system for automatic batch injection of suspended cells is proposed. To facilitate the process, these suspended cells are held and fixed by a specially designed cell holding device. A micropipette equipped with a PVDF micro force sensor is integrated in the proposed system. A force sensor is utilized to measure real time injection force applied to the cells during the injection process. With the force feedback provided by the PVDF micro force sensor, the motion of the injecting pipette during insertion, which cannot be directly observed by the microscope, is controlled utilizing the calibrated desired injection force trajectory. A vision and force algorithm is then proposed and applied to the motion control of the injection pipette in three-coordinate directions during an "out-of- plane" cell injection process. Finally, experimental results are given to demonstrate the effectiveness of the proposed approach.