Fused Silk: A New Bio-Based Material Stronger Than Bone and Wood, Approaching Kevlar
Researchers at Tufts University, Imperial College London, and the University of Michigan have developed a groundbreaking method to transform silk into solid materials. By fusing fibers under controlled heat and pressure—without dissolving them—the new process preserves the silk's natural strength. The resulting material outperforms bone and wood in tensile toughness and approaches the performance of Kevlar.
Key Details
- Raw Material: The material is made from commercially available silk moth cocoon fibers, treated with mild sodium carbonate to remove sericin, then aligned and hot-pressed. Heat mobilizes amorphous protein regions to bond the fibers.
- Optimal Processing: Temperatures between 257°F and 419°F and pressures between 1,900 and 9,800 atmospheres produced optimal strength.
- Unique Structure: Fused silk has a hierarchical structure similar to wood. Properties can be tuned by adjusting processing conditions, allowing for a range of material characteristics.
- Optical Properties: The material is transparent to visible light and polarizes terahertz radiation, suggesting potential applications in 6G communications.
- Biomedical Potential: In animal studies, fused silk proved stable and biocompatible. Less dense versions allowed cell infiltration; denser versions resisted degradation. Possible orthopedic uses include plates, pins, and screws.
"The material can compete with plastics, glass fiber, carbon fiber composites, and wood." — Research Team
Background
Traditional silk processing dissolves fibers into fibroin proteins, which loses inherent strength. The new method preserves the fiber structure entirely, maintaining its natural mechanical integrity. The study was published in Nature Sustainability.
"The tunability may broaden medical applications, including orthopedic fixation devices." — Li, Researcher