Direct conversion of rheological compliance measurements into storage and loss moduli

摘要

We remove the need for Laplace/inverse-Laplace transformations ofexperimental data, by presenting a direct and straightforward mathematicalprocedure for obtaining frequency-dependent storage and loss moduli($G'(\omega)$ and $G"(\omega)$ respectively), from time-dependent experimentalmeasurements. The procedure is applicable to ordinary rheological creep(stress-step) measurements, as well as all microrheological techniques, whetherthey access a Brownian mean-square displacement, or a forced compliance. Datacan be substituted directly into our simple formula, thus eliminatingtraditional fitting and smoothing procedures that disguise relevantexperimental noise.