Fiber optic sensors and smart fabrics

This paper presents novel work on developing fiber optic micro-sensors and integrating them into soldiers' uniforms. These fiber optic sensors can be used to sense various battlefield hazards in real-time, such as chemical and biological warfare threats, above-normal field temperatures, and other hazards. The developed fiber optic sensors use multifunctional materials as modified cladding materials, which can sense various environmental conditions. Appropriate materials can be chromogenic materials, chemical or biological agent, conducting polymer and others. The sensing function is based on their ability to change the light propagation characteristics of optical fibers. Two types of materials, (1) thermochromic material, segmented polyurethane-diacetylene copolymer (SPU) [synthesized at the University of Akron (UA)], and (2) conducting polymer, polyaniline [synthesized at the University of Pennsylvania (U of P)], have been successfully used in this feasibility study to prove the concept of the design and development of the optical fiber sensors. Segmented polyurethane-diacetylene copolymer was selected as the thermochromic material for temperature sensor application. Polyaniline was chosen as the photo-chemical polymer for chemical sensor application. The developed methodology for building these sensors includes modifying the regular optical fibers, by replacing the fiber passive cladding with those sensitive materials. The integration of the sensory system into textile structures, done in collaboration with the North Carolina State University (NCSU), also showed good progress. An overview on the developed methodology and technical achievement is presented.