Thomas Angus / Imperial College London
The material also has optical transparency and is biodegradable, and could be used in the future for temporary implants or bioengineering devices.
A new published in Nature Sustainability reports the creation of a new silk-based material with strength and toughness comparable to Kevlar.
The discovery is based on an innovative process that transforms natural silk fibers into a ultra-dense and transparent materialwithout the need for intense chemical processing or synthetic additives.
The research team, led in part by Chunmei Li of Tufts University, says the new “molten silk” combines exceptional mechanical strength with biodegradability, offering a possible environmentally friendly alternative to plastics and petroleum-derived composites.
Spider silk has long fascinated scientists for its remarkable strength, often described as several times stronger than steel in relation to weight. Natural silkworm silk is also known for its durability and flexibility, but traditional methods of processing silk into advanced materials often require chemical treatments that damage the fiber’s natural structure.
The new technique avoids many of these disadvantages using carefully controlled heat and pressure to fuse aligned silk fibers, preserving their internal architecture, explains .
Researchers removed the sticky outer layer from commercially available silk fibers before subjecting them to temperatures between 125 and 215 degrees Celsius and pressures reaching thousands of atmospheres. Finding the right balance proved crucial: too little heat and pressure left silk brittle and soft, while excessive conditions caused brittleness and structural rupture.
Under ideal conditions, however, fibers joined together tightlyforming a material with an internal structure similar to wood, capable of distributing tension extremely efficiently.
According to the study, the resulting molten silk demonstrated a tensile strength greater than that of bone and roughly comparable to Kevlar, the synthetic material widely used in bulletproof vests and protective gear. Ballistic tests also showed that the material was as puncture-resistant as carbon fiber-reinforced polymers typically used in aircraft and automobile manufacturing.
In addition to its resistance, the material also has optical transparency and light manipulation properties that researchers believe could make it useful in next-generation sensors, imaging systems and wireless technologies.
The team also tested the material on ratsfinding that it gradually biodegraded over time, suggesting possible medical applications such as temporary implants or bioengineering devices.
The researchers say that the next challenge will be to expand production and adapt the material for more complex industrial uses. The team is now looking for commercial and industrial partners to explore applications in advanced manufacturing and electronics.
