Mechanical force response of single living cells using a microrobotic system

In this paper, we investigate mechanical force response of single living cells at different conditions using a microrobotic system. Zebrafish eggs at different developmental stages were collected and an integrated biomanipulation system was employed to measure cellular force during penetrating the egg envelope, the chorion. First, the biomanipulation system integrated with cellular force sensing instrument is implemented to measure the penetration force of the chorion envelope and then to characterize mechanical properties of zebrafish embryos. Second, the cellular force sensing of penetrating the chorion envelope at each developmental stages was experimentally performed. The results demonstrated that the biomanipulation system with force sensing capability can measure cellular force in real-time while the injection operation is undergoing. The magnitude of the measured cellular force decrease as an embryo develops. This result quantitatively describes the chorion softening in zebrafish embryos. Experimental results also demonstrate that subtle modification of the chorion, the extracellular matrix of the egg, can be monitored physically using the developed real-time force sensing system.