Non-contact force sensing for real-time stressing of biological cells

Mechanical force sensing is an important and integral component in the study of the viscoelastic properties of biological cells. In this study, a vision-based non-contact force sensing technique for real-time stressing of biological cells by a vision-guided robotic micromanipulation system is introduced. The system is capable of providing real-time external mechanical stressing on biological cells with a predefined profile and estimating the cell membrane deformation using the proposed cell strain model. One of the phenomena manifesting the viscoelastic properties of cells is the gradual reduction of reaction force in the compressive stress under cyclic loading. The applied force with respect to the cell membrane strain and the number of stressing cycles is modelled and validated by different zebrafish embryos. The experimental results show that the proposed force model can estimate the reaction force of cell membrane with the average maximum error of 10.07%.