PASSIVE TUNABLE FIBERS AND MATRICES

Active smart electrorheological fluids in building materials are expensive, need to be widely dispersed, and require large amounts of electricity. These practical considerations led to the consideration of ways of having similar effects in a matrix but using different materials. Tuneable fibers is an inexpensive dispersed passive system, requiring no electricity. The modulus of elasticity of a solid-filled fiber is very different from a liquid- or gas-filled fiber or a hollow fiber. The ability to empty and fill fibers with a material which could change phase in the fiber or in the matrix in response to some stimulus or signal from the environment is promising. In the laboratory we have used filled fibers which empty their contents into the matrix in response to a change in the environment. In this case, in which it is a substitute for ER fluid, a blast, vibration, or shaking motion could release a catalyst, monomer, or adhesive from flexed or uncoated fibers. These could cross-link with a resin or polymerize in the matrix. Passive tuneable fibers could also be used for nonbuilding applications such as radar evasion. The changing modulus profile would be, thus, an advantageous performance parameter.