The storage modulus, G (in kPa), as a function of the amount of shear, s, for (a) soft, (b) medium, and (c) stiff gels. For each gel stiffness, data for four independent tests and the curve of the best fit are shown. Material parameters are as follows for each gel stiffness: (a) soft gel, kPa, ; (b) medium gel, kPa, ; (c) stiff gel, kPa, . The shear modulus μ used in the linear elasticity model (LIN) is also displayed for each gel stiffness.