The Development of Fibers That Mimic the Core–Sheath and Spindle‐Knot Morphology of Artificial Silk Using Microfluidic Devices

Abstract

Spider and silkworm produce diverse silk fibers from spinning dopes through smart spinnerets. Spider's capture silk is composed of core thread and periodic spindle‐knots, while silkworm silk consists of fibroin core and sericin outer layer. To mimic the morphologies of natural heterostructured silks, artificial fibers are dry‐spun using a multichannel microfluidic chip, served with a highly viscous core solution of regenerated silk fibroin and low viscosity sheath solution of sericin. Silk fibers with core–sheath, groove, and spindle‐knot structures are obtained by controlling the flow rates and viscosities of the two microfluids depending on the laminar flow, Kelvin–Helmholtz instability, or Plateau–Rayleigh instability.

Effects of surfactant adsorption on the formation of compound droplets in microfluidic devices

“…It has been reported that the Kelvin-Helmholtz (KH) instability probably occurs when the velocity difference is higher than 0.1 m s À1 for liquid-liquid uids with similar densities. 36,37 With the increase of the velocity difference, a wave-like interface between the O and W2 phases appears, indicating that the KH instability occurs. Finally, the head of the O phase narrows, but it is very difficult to obtain W1/O compound droplets in the W2 phase with 0.002% PVA even with increasing the W2 ow rate.…”

Water Harvesting of Bioinspired Microfibers with Rough Spindle‐Knots from Microfluidics

“…preparation of fibers. [14] The microflow method not only avoids the drawbacks of impregnated pulling and wet self-assembly of single-strand limited preparation, but also avoids the high voltage risk and the drawbacks of single-strand filament difficulty in electrospinning. At the same time, compared with solution coating microflow technology, it broadens the applicable range of materials.…”

“…There are a lot of biomimetic spider silk preparation methods such as dip coating, fluid coating, electrospinning technique, wet‐assembly, and microfluidics . Among these methods, microfluidic spinning technology has gradually become a research hotspot because of its large‐scale controllable preparation of fibers . The microflow method not only avoids the drawbacks of impregnated pulling and wet self‐assembly of single‐strand limited preparation, but also avoids the high voltage risk and the drawbacks of single‐strand filament difficulty in electrospinning.…”

Continuous fabrication of near-infrared light responsive bilayer hydrogel fibers based on microfluidic spinning

“…Recently, NIR light responsive hydrogels have attracted wide interest because NIR light is easy to be controlled. NIR light responsive hydrogels were usually prepared by combining thermo-sensitive polymer such as PNIPAM with light-absorbing nanoparticles such as carbon nanotubes (14), graphene (15), graphene oxide (16)(17)(18), gold nanorods (19,20) and ferroferric oxide nanoparticales (21,22). Graphene oxide has the advantages of high NIR light absorbance and conversion efficiency.…”