Flow Analysis of Regenerated Silk Fibroin/Cellulose Nanofiber Suspensions via a Bioinspired Microfluidic Chip

Abstract Microfluidic spinning has been used to mimic and discover the natural spinning process of silk. However, it is still challenging to understand the orientation and alignment of silk‐spinning through microfluidic chips. Here, flow analysis is performed for a bioinspired microfluidic chip mimicking the shape of a spider's major ampullate gland and spinning duct by in situ small angle X‐ray scattering and simulations using the finite element method. A composite suspension of regenerated silk fibroin and cellulose nanofibers show higher orientation and alignment after flowing through the microfluidic chip. This confinement can be attributed to the drop in the extrusion pressure of the silk proteins and the shear and elongation forces from the anisotropic microchannel. This work reveals the microstructure−property relationship of fibers obtained through the microfluidic chip. Hence, it paves the way to uncover the mystery behind the natural spinning process and further provides comprehensive and systematic insights into preparing highly oriented artificial fibers for biomedical applications.