Force measurement and mechanical characterization of living Drosophila embryos for human medical study

Abstract

The objective of this paper is to investigate and characterize the force behaviour and mechanical properties of living Drosophila embryos using an in situ polyvinylidene fluoride (PVDF) piezoelectric microforce-sensing tool with a resolution in the range of submicro newtons. The Drosophila embryo is one of the most studied organisms in biological research, medical research, genetics, and developmental biology and has implications in the cure of human diseases. It is also used to study the wiring of the human brain and the nervous system. For a highly efficient and accurate microinjection of genetic material into a Drosophila embryo, it is absolutely necessary to allow close monitoring of the magnitude and direction of microinjection and other biomanipulation forces acting on the embryo during the injection process. In this paper, a networked microrobotic biomanipulation platform integrating a twoaxis (two-dimensional) PVDF microforce-sensing tool is used to implement force sensing and injection of living Drosophila embryos. Based on the event synchronization for the feedback of injection video and microforce, the developed networked microrobotic platform can greatly advance operations in microinjection and biomanipulation. Through experiments, quantitative relationships between the applied force and membrane structural deformation of embryos in different stages of embryogenesis and their microinjection force behaviours were investigated. Ultimately, the technology will provide a critical and major step towards the development of automated biomanipulation for batch injection of living embryos in genetic and developmental studies, which will facilitate the development of medicine for the cure of human diseases.