Design and Precision Position/Force Control of a Piezo-Driven Microinjection System

This paper presents the design and development of a piezo-driven cell injection system with the fusion of force and position control. By integrating a polyvinylidene fluoride force sensor for detecting the penetration force of biological cells and a strain-gage sensor for measuring the micropipette relative position in real time, the entire cell micromanipulation system features low cost, convenient installation, and easy maintenance. The challenge of transition jerk between the force and position controller switching is reduced by introducing a weight coefficient method. An adaptive sliding mode control with parameter estimation scheme is implemented to compensate for the hysteresis nonlinearity and disturbance of the piezoelectric actuator. The injection force is controlled by realizing an incremental proportional-integral-derivative controller. The effectiveness of the developed cell injection system is experimentally verified by penetrating zebrafish embryos. The experimental results lay a foundation for the further biological manipulation research, such as the automatic batch injection of zebrafish embryos.