Research Of Automated Micromanipulation Technology Based On Multifunctional Cell Manipulation Device

In biological research and experiments, robotic manipulation can replace manualoperations and avoid the phenomenon of human fatigue due to prolonged high-intensitylabor, which greatly reduces the skill requirements of the operator and makesbiotechnology available for more people. Application of a robotic micromanipulationsystem for cell engineering experiments can improve the efficiency and success rate of theoperation with simplified and automated cell manipulation. Focused on automation andintelligent micromanipulation themes, this paper developed a multifunctional cellmanipulation device and then constructed a computer-controlled roboticmicromanipulation system, using opto-mechatronic technologies to achieve good-stabilityand high-repeatability automated cell manipulation.Firstly, the imaging principle of the biological inverted microscope integrated withCCD camera was analyzed. Automatic search and location for the target was performedaccording to the structure and characteristics of the microrobots, consequently themechanism of microinjection and vitrification for embryos was studied to provide atheoretical basis for further study on robotic micromanipulation.Moreover, aiming at the requirements of integrated batch cell manipulation, amultifunctional cell manipulation device was developed, which could not only bealternative to assembly of several culture dishes, but also be easy to locate targets. Cellimmobilization, washing, handling and freezing could be conducted with this device. Afterselecting appropriate mechanical positioning system and microscopic vision system, eachof the components and the drive was connected to the correct port to build a microroboticsystem.PID controller with visual feedback was used to achieve a precise closed-loop controlfor the X-Y stage,3DOF manipulator and micro-pump. Based on microscopic visual servotechnology, Hough Circle Transform was applied to recognize cells and control the stagefor cell tracking; Depth-From-Defocus algorithm was applied for autofocus of themicroscope, inspecting with image definition criterion function if needed.At last, with mouse oocytes placed in the micro-fabricated device, the robotic system automatically performed cell adhesion immobilization and vitrification.9cells can be fixedwithin1min that gained a substantial increase in cell injection efficiency; vitrificationcould be completed within25~35s, and its success rate was16.7%higher than manualoperation. Performance comparisons of robotic and manual vitrification proved that roboticsystem had the advantage of good stability and high repeatability with application ofappropriate control methods and microscopic vision algorithms.