Pipette aspiration of hyperelastic compliant materials: Theoretical analysis, simulations and experiments

This paper explores the pipette aspiration test of hyperelastic compliant materials. Explicit expressions of the relationship between the imposed pressure and the aspiration length are developed, which serve as fundamental relations to deduce the material parameters from experimental responses. Four commonly used hyperelastic constitutive models, e.g. neo-Hookean, Mooney–Rivlin, Fung, and Arruda–Boyce models, are investigated. Through dimensional analysis and nonlinear finite element simulations, we establish the relations between the experimental responses and the constitutive parameters of hyperelastic materials in explicit form, upon which inverse approaches for determining the hyperelastic properties of materials are developed. The reliability of the results given by the proposed methods has been verified both theoretically and numerically. Experiments have been carried out on an elastomer (polydimethylsiloxane, 1:50) and porcine liver to validate the applicability of the inverse approaches in practical measurements.