Reconstructed Hierarchically Structured Keratin Fibers with Shape‐Memory Features Based on Reversible Secondary‐Structure Transformation

Abstract

Biocompatible and biodegradable shape‐memory polymers have gained popularity as smart materials, offering a wide range of applications and environmental benefits. Herein, we investigate the possibility of fabricating regenerated water‐triggered shape‐memory keratin fibers from wool and cellulose in a more effective and environmentally friendly manner. The regenerated keratin fibers exhibit comparable shape‐memory performance to other hydration‐responsive materials, with a shape fixity ratio of 94.8 ± 2.15% and a shape recovery rate of 81.4 ± 3.84%. Owing to their well‐preserved secondary structure and crosslinking network, keratin fibers exhibit outstanding water‐stability and wet stretchability, with a maximum tensile strain of 362 ± 15.9%. In this system, we investigate the reconfiguration of the protein secondary structure between α‐helix and β‐sheet as the fundamental actuation mechanism in response to hydration. This responsiveness is studied under force loading and unloading along the fiber axis. Hydrogen bonds act as the “switches” clicked by water molecules to trigger the shape‐memory effect, while disulfide bonds and cellulose nanocrystals play the role of “net‐points” to maintain the permanent shape of the material. Water‐triggered shape‐memory keratin fibers are manipulable and exhibit potential in the fabrication of textile actuators, which may be applied in smart apparel and programmable biomedical devices.This article is protected by copyright. All rights reserved

Constructing Stiff β-Sheet for Self-Reinforced Alginate Fibers

“…The mechanisms of β-sheetenced mechanical properties were similar to those of protein-based fibers. Table 1 marizes the contents of helix, β-sheet, and random coil for a few spider silk fibers, r erated silk fibroins fibers, silkworm silk fibers, and regenerated wool keratin f [28,30,[43][44][45][46][47][48]. Apart from the different reinforcing mechanisms reported in the litera the changes in mechanical properties presented similar positive correlations for te strength versus β-sheet contents.…”

Soft Fiber/Textile Actuators: From Design Strategies to Diverse Applications

“…Braid yarns involve intertwining multiple strands of yarn in a braid-like pattern, which have a unique texture and appearance and can enhance its strength and durability . Due to these special structures, the yarn-based actuators exhibit interesting actuation behaviors in response to external stimuli …”

“…50 Due to these special structures, the yarn-based actuators exhibit interesting actuation behaviors in response to external stimuli. 51 Textiles are hierarchical structures composed of fibers and yarns. Many textile technologies, such as weaving, braiding, knitting, and electrospinning, hold promise for fabricating multifunctional textile actuators.…”