High-resolution microscopy assisted mechanical modeling of ultrafine electrospun network

Abstract

This paper demonstrates a novel hi-resolution microscopy-assisted computational approach to mechanical modeling of ultrafine electrospun networks (ESN). Morphological data extracted from X-ray microtomography (μCT) of ESN made of poly(lactic-co-glycolic acid) (PLGA), supplemented by data acquired from the nanoscale flexural test of a single fiber, was used to create a volumetric finite element (FE) model of the investigated ESN. The results of the carried-out FE simulation have been successfully validated against the results of the quasi-static tensile test. The accuracy and the reliability of the μCT-based ESN geometry have been proved by the comparison with the scanning electron microscopy (SEM) data and by the numerical analysis of fluid flow across the rendered ESN structure. The designed methodology enables the analysis of potential factors affecting the mechanical properties of electrospun structures made of aliphatic polyesters, like the depth of fiber fusion, the ESN geometric inaccuracies, and the fiber diameter distribution. Moreover, in the study, the novel experimental setup enabling for single fiber AFM flexural test was proposed, assuming deposition of fibers directly on polystyrene (PS) substrate containing crater-like wells. Additionally, the presented study contains the numerical analysis of the effect of the substrate stiffness on the results of the three-point bending test of a single fiber.