Researchers at Imperial College London, University of Michigan Engineering, and Tufts University have transformed silk threads into transparent, plastic-like materials that could become the foundation for 6G network components—a breakthrough that might rescue textile waste while building the next generation of wireless technology.
The discovery matters because it solves two urgent problems at once: the fashion and textile industry generates enormous amounts of unsalvageable fiber scraps, and engineers have struggled to create materials that can manipulate terahertz light—the frequencies essential to 6G networks, which could transmit data hundreds of times faster than 5G—without blocking or absorbing that light. The new silk-based material accomplishes both feats.
When silk fibers are heated to between 257°F and 419°F under 1,900 to 9,800 atmospheres of pressure, water evaporates and the tangled regions of the silk fuse into a single sheet while preserving the neat crystalline folds within the fibers. This process, far simpler than previous methods, requires only boiling the silk to remove sericin—the natural protein that binds fibers together. No harsh chemical solvents needed. "Even tiny fibers can be pressed into sheets," explained Chunmei Li, a research assistant professor in biomedical engineering at Tufts University. "It can be a very simple, one-step process."
What emerges is remarkable. The materials are lightweight yet stronger than many metal alloys and conventional plastics made from fossil fuels. In ballistics tests, they matched the puncture resistance of carbon-fiber-reinforced polymers—the materials used in airplane bodies and car chassis. Beyond durability, the materials twist, or polarize, terahertz frequencies of light in ways that are unusually difficult to engineer. This polarization capability could open up entirely new channels for data encoding in 6G systems.
"It's difficult to engineer a material terahertz optical activity that can rotate light while also being nearly transparent," said Nick Kotov, the Irving Langmuir Distinguished University Professor of Chemical Sciences and Engineering at the University of Michigan and a co-corresponding author of the study published in Nature Sustainability. "This composite is unique in that it can do it for the frequencies that are essential for multiple future technologies. Typically, such bioderived materials absorb terahertz light very strongly, so you get very little light out."
The team fine-tuned how much the material twists light by adjusting temperature and pressure during pressing—a level of control that opens possibilities far beyond 6G. The materials showed biodegradability in laboratory tests with mice, suggesting they could serve as temporary medical implants. Their strength and flexibility also make them promising for sports gear, shipping containers, and specialized packaging.
The motivation to pursue this work came from a stubborn reality in the fashion industry: once textile fibers become too short to weave, they typically end up dissolved in chemical solvents and dried into powder—a wasteful and unsustainable solution. Emiliano Bilotti, an associate professor in multifunctional and sustainable polymer composites at Imperial College London, pushed back against that approach. "I never believed that was a sustainable solution," he said.
Now the team is exploring how to scale their manufacturing process to larger, more complex shapes—the next critical step toward real-world applications. If successful, this work could mean that discarded silk scraps become the building blocks of tomorrow's wireless networks while reducing chemical waste in the textile industry.