Bio-Inspired 4D Printing of Dynamic Spider Silks

Abstract

Spider silks exhibit excellent mechanical properties and have promising application prospects in engineering fields. Because natural spider silk fibers cannot be manufactured on a large scale, researchers have attempted to fabricate bio-inspired spider silks. However, the fabrication of bio-inspired spider silks with dynamically tunable mechanical properties and stimulation–response characteristics remains a challenge. Herein, the 4D printing of shape memory polyurethane is employed to produce dynamic bio-inspired spider silks. The bio-inspired spider silks have two types of energy-absorbing units that can be adjusted, one by means of 4D printing with predefined nodes, and the other through different stimulation methods to make the bio-inspired spider silks contract and undergo spiral deformation. The shape morphing behaviors of bio-inspired spider silks are programmed via pre-stress assemblies enabled by 4D printing. The energy-absorbing units of bio-inspired spider silks can be dynamically adjusted owing to stress release generated with the stimuli of temperature or humidity. Therefore, the mechanical properties of bio-inspired spider silks can be controlled to change dynamically. This can further help in developing applications of bio-inspired spider silks in engineering fields with dynamic changes of environment.

Electrospun Nanofibrous UV Filters with Bidirectional Actuation Properties Based on Salmon Sperm DNA/Silk Fibroin for Biomedical Applications

“…Differently, a radius of curvature of approximately 3.5 cm reached in about 1.5 min was achieved by the ESF/E patch. While the upward bending of the patch upon exposure to water vapor can be rationalized by considering the differential swelling of the SF across the thickness leading to a stress gradient, – the contraction behavior is due to the relaxation of the structure to the coiled one when high relative humidity triggers the structural glass transition. , These patches, after being exposed to water vapor, became transparent (see Figure d), and during this process, the nanofibrils aggregate, leading to a less porous patch, making this effect more evident in the ESF/E sample (Figure b). ESF and ESF/E patches, after the water vapor treatment, were then immersed in PBS for 1 week.…”

Recent Advances in the Additive Manufacturing of Stimuli‐Responsive Soft Polymers

“…[151,[437][438][439] These structures have drawn growing research interests, thanks to their distinct functions and potential applications in deployable structures and reversible energy absorption devices. [440][441][442][443] Mechanical properties of these materials emerge from the 3D spatial orientation of the microlattice structures. [444] SRP-based metamaterials with large deformation, reconfigurable, programmable, and tunable properties have been developed by different researchers.…”