Air Force Scientists Study Artificial Silk for Body Armor, Parachutes

By Donna Lindner, Air Force Research Laboratory

WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- Who doesn’t like to feel warm in the winter and cool in the summer? Artificial silk fibers can be woven into sizeable, flexible fabrics using existing textile manufacturing methods.

Inspired by the qualities of fibers found in nature, scientists at the Air Force Research Laboratory, headquartered here, and Indiana’s Purdue University are experimenting to develop a functional fiber that can be woven into sizeable, flexible fabrics using existing textile manufacturing methods.

Researchers are studying the cooling and temperature regulation properties of natural silk in order to apply it to synthetic fibers such as artificial spider silk, which is both stronger than the polymer known commercially as Kevlar and more flexible than nylon.

Cool Fabric

Silk exhibits passive radiative cooling properties, meaning that it radiates more heat than it absorbs when in direct sunlight. On hot summer days, silk drops 10-15 degrees Fahrenheit when compared to reflective materials.

The cooling fabric is of tremendous potential benefit to the warfighter wearing body armor.

Body armor and parachutes are two articles in line to be constructed with artificial spider silk. Body armor is burdensome due to its heavy weight and the non-breathing material they are fabricated with. Parachutes constructed of the new material are stronger and able to carry larger payloads.

Estimates indicate that, while artificial spider silk may initially cost twice as much as Kevlar, the product’s minimal weight, incredible strength, elasticity and potential adaptability for other needs are characteristics that enhance its salability.

Aiding Warfighters’ Comfort

“Making the warfighter more comfortable by enhancing body armor is just one of the many improvements my team hopes to make by studying natural silk,” said Augustine Urbas, a researcher in the Functional Materials Division of the AFRL’s Materials and Manufacturing Directorate.

Urbas added, “Understanding natural silk will enable us to engineer multifunctional fibers with exponential possibilities. The ultra-strong fibers outperform the mechanical characteristics of many synthetic materials as well as steel. These materials could be the future in comfort and strength in body armor and parachute material for the warfighter.”

Tents for forward operating bases could be composed of the natural material. This would enable the warfighter to work in a cooler environment.

Processing Silk Protein

Fibroin, a silk protein secreted by the silkworm, can be processed into a lightweight material for fabricating artificially engineered synthetic and optical materials.

The structured optical materials can reflect, absorb, concentrate or split light enabling a material to perform differently in a specific situation.

Understanding light transport and heat transfer will lead to various innovations. According to AFRL researchers, learning from silk to assist with developing material synthesis and design processes in the future is a great opportunity.