Design and testing of a new microinjector with FBG force sensor for robot-assisted single cell microinjection

Microinjection with force sensing has demonstrated robust performance in improving the cell survival rate and adjusting robot motion parameters. In this article, a novel force-sensing microinjector is presented based on fiber Bragg grating (FBG) sensors to precept three-dimensional (3D) forces. Fibers are processed with acid to become thinner and more sensitive. Three optical fibers are affixed to the outer surface of the glass needle along the axial direction. Benefiting from the novel configuration of the FBG sensors, the hollow channel of the glass needle can be used to inject exogenous substances. Moreover, a prototype has been fabricated for the experiment. Experimental results demonstrate the proposed force sensor can achieve a resolution of 66.8 μN for puncture forces. Repeatability and temperature compensation experiments show the force sensor can provide a consistent and accurate measurement. The developed force sensor has been applied to the microinjection of the zebrafish embryos, which is a promising tool for perceiving cell manipulation microforces.