Static Response of Coated Microbubbles: Modeling Simulations and Parameter Estimation

The mechanical response of contrast agent microbubbles subject to a static load was investigated in force-deformation curves. Asymptotic relations are fitted with experimental AFM measurements of polymeric microbubbles available in the literature. The elastic modulus and shell thickness are estimated based on the transition from the classical linear (Reissner) to the nonlinear (Pogorelov) regime. The estimated value of the elastic modulus is in the order of GPa and the shell thickness in the order of nm, in good agreement with independent estimates. Numerical simulations recover the above transition and identify a third regime, dominated by the compressibility of the enclosed gas.