Control system for microinjection of zebra fish embryos

Abstract

This report discusses the development of a bio-micromanipulation system for Zebra fish embryo injection. This system is designed to automate the process of injection and also to apply a desired force (in µN) on the fish egg (shell) as well as on the embryo. The purpose is to study the effect of applying a constant force over a particular duration on the development of the embryo. This concept has been pioneered by Dr. Luo Huong in the research institute SIMTECH.

The position of the needle is controlled by a voice coil actuator. A flexure stage is used to absorb excess force which can damage the embryo. The position of the flexure stage is contorted by a 6 axis stage and the position of the egg is controlled by a 3 axis stage. The needle is attached to a force sensor. All the mechanical components are assemble and tested for efficiency and precision.

A program with a graphical user interface was developed in Labview 7.0 to integrate, communicate and control all the electronic components. The program communicates to a current source which drives a voice coil actuator and controls the position of the needle. The force controller communicates the current force reading to the program. PID control logic was used to maintain a desired force. All the exceptions were handled.

The system device was then tested for its performance with good results. The experiment results and possible improvements are discussed. This project, for the first time in the history of bio-micromanipulation, has demonstrated that an automated system can apply a desired micro force on a living embryo over a given duration of time. It is absolutely essential to do further research on the force sensor for better performance.