Unmanned air vehicles such as the Predator and Global Hawk enable soldiers to engage an enemy from a safe distance. However, as impressive as these technologies may be, it still takes ground troops to hold a position. The military, therefore, is investigating some unique ways to empower the infantryman, including uniforms spun of photonic bandgap fibers.Founded in March 2002, Massachusetts Institute of Technology's Institute for Soldier Nanotechnologies has received a $50 million grant from the US Army to investigate uniforms based on nanomaterials that protect against ballistic and chemical/biological threats, that distinguish friend from foe and that administer medical treatment. The futuristic battle suit would be a lightweight system that integrates a variety of functions into the material, eliminating the need for bulky accessories and modular attachments.The researchers have made important strides with a photonic bandgap fiber developed by Yoel Fink, an assistant professor of materials science and engineering at MIT. "The work with photonic bandgap structures has gone quite far," said Paula Hammond, who leads the investigation. "It's going to be one of the early successes."Massachusetts Institute of Technology's Yoel Fink frames his face with a photonic bandgap fiber. Compared with conventional wire, held in his left hand, the reflective properties of the new material are apparent. Courtesy of Donna Coveney, MIT. By incorporating photonic band-gap fibers into the fabric of the battle suit, Hammond explained, the uniform could reflect a specific wavelength in the IR that would be recognizable by fellow soldiers. The mirrored fabric also could protect the soldiers from radiation and could change color for camouflage.The scientists have developed a fabric with hundreds of alternating layers that are tunable to various wavelengths. The material combines the characteristics of metallic and dielectric mirrors, reflecting light from every angle.Much remains to be done to make the photonic material as ductile as a polymeric fiber, Hammond said. Durability and stability are key because uniforms must tolerate the stresses of being worn and laundered. And the fabric must be mass-produced at a reasonable cost.Nevertheless, Hammond is encouraged by the possibilities that photonics has to offer. She suggested that similar uniforms eventually could find applications for emergency workers, police, firefighters and others requiring similar protection.