Spider Silk Secrets Unveiled: Stretching Key to Strength, Applications in Medicine and Armor

Northwestern University researchers have unlocked the secret behind spider silk's exceptional strength: the stretching process. Published in Science Advances, the study reveals that stretching aligns protein chains within the silk fibers and increases bonds between them, leading to stronger, tougher material. Using computational models and laboratory experiments with engineered spider silk, the team validated that stretching significantly enhances the silk's mechanical properties. "Researchers already knew this stretching, or drawing, is necessary for making really strong fibers," said Northwestern's Sinan Keten, the study's senior author. "But no one necessarily knew why." The findings pave the way for designing silk-inspired proteins for applications like biodegradable sutures, wound-closure gels, and blast-proof body armor. Spider silk's biodegradability makes it ideal for medical uses, offering a sustainable alternative to petroleum-based plastics. Jacob Graham, the study's first author, notes the potential to modify the fiber's mechanical properties simply by adjusting the amount of stretching. The study was supported by the National Science Foundation. The research was published in March 2025.