Groove Formation Modeling in Fabricating Hollow Fiber Membrane for Nerve Regeneration

Abstract

Hollow fiber membrane (HFM) is one of the most popular membranes used for different industrial applications. Under some controlled fabrication conditions, axially aligned grooves can be formed on the HFM inner surface during typical immersion precipitation-based phase inversion fabrication processes. Such grooved HFMs are finding promising medical applications for nerve repair and regeneration. For better nerve regeneration performance, the HFM groove morphology should be carefully controlled. Toward this goal, this study has modeled the HFM groove number based on the shrinkage-induced buckling model in HFM fabrication. HFM has been modeled as a three-layer long fiber membrane. The HFM inner layer has been treated as a thin-walled elastic cylindrical shell and buckles due to the shrinkage of the compliant intermediate layer during solidification. The groove geometry, especially the groove number, has been reasonably predicted compared with the experimental measurements. This study has laid a mathematical foundation for HFM circumferential instability modeling, which is of recent interest in membrane fabrication.