Airport luggage screening can be tedious and time-consuming, but has prevented mid-air disasters caused by bombs secreted in the holds of cargo or passenger planes. The University of Sheffield and a spin-out company, Blastech Ltd., Sheffield, England, have developed a second line of defense for terrorist bomb plots or accidental explosions on aircraft. The Fly-Bag features multiple layers of novel fabrics, composites and coatings that contain luggage and the potential explosive force of a bomb that may make it through airport security.
The fundamental principle underlying the Fly-Bag design is shear thickening fluids (STFs), using an elastomer that increases its viscosity in response to impact. Following sudden impact, STFs in fabric impregnated or coated with the substance clump together and thicken to provide a gas seal in the bag at very high strain rates while resisting flame and heat. The STF coats the fabric yarn and stiffens the fabric to hold the blast. The Fly-Bag will be on the market in a few years, providing a lighter weight and less expensive option than the current hardened luggage containers used in some aircraft.