Design and Evaluation of a Piezo-Driven Ultrasonic Cell Injector

Abstract

In this chapter, a novel piezo-driven cell injection system for automatic batch injection of suspended cells is presented; it has simplified operational procedure and better performance than the previous ones. Specifically, this new piezo-driven cell injector design has three aspects of merits: 1) by centralizing the piezo oscillation energy on the injector pipette, it eliminates the vibration amplitude of other parts of the micromanipulator; 2) meanwhile, a small piezo stack is sufficient to perform the cell injection process; and 3) detrimental lateral tip oscillations of the injector pipette are attenuated to satisfactory amount even without mercury column. The removal of mercury enables wide applications of this advanced cell injection technology in a number of cell manipulation scenarios. Furthermore, ultrasonic vibration micro-dissection (UVM) theory is utilized to analyze the piezo-driven cell injection process, and lateral oscillation of injector pipettes is investigated. Experiments on cell injection of a large amount of zebrafish embryos (n=300) indicate that the injector pipette is capable of piercing through cell membranes with low injection speed and almost no deformation of the cell wall, but with a high success rate.