Characterization of cellular mechanical behavior at the microscale level by a hybrid force sensing device.

This paper deals with the development of an open design platform for characterization of mechanical cellular behavior. The resulting setup combines Scanning Probe Microscopy (SPM) techniques and advanced robotic approaches in order to carry out both prolonged observations and spatial measurements on biological samples. Visual and force feedback is controlled to achieve automatic data acquisition and to monitor process when high skills are required. The issue of the spring constant calibration is addressed using an accurate dynamic vibration approach. Experimentation on the mechanical cell characterization under in vitro conditions on human adherent Epithelial Hela cells demonstrates the viability and effectiveness of the proposed setup. Finally, the JKR (Johnson, Kendall and Roberts), the DMT (Derjaguin, Muller and Toporov) and Hertz contact theories are used to estimate the contact area between the cantilever and the biological sample.