Force-indentation curves of spheroidal objects.

Abstract

Currently, there are many methods to determine the forces and energy necessary to deform cells. These methods, however, are slow and require testing outside of the body. In this paper, we propose a theoretical method to recover the energy and force vs. indentation curves produced by the deformation using an Atomic Force Microscope. The theory depends on parameters such as Young’s modulus, object length, and Poisson’s ratio, which are obtained by fitting our mathematical expressions to experimental force vs. indentation curves. Thus, our results provide a systematic way to measure those material parameters in general, but in particular in soft matter where the materials are highly heterogeneous and their properties are often dependent on external stresses.