Solid-State Phase Change Composite Shield for Protection From High Energy Lasers

In collaboration with the University of Virginia, TauMat is proposing to develop a thin, lightweight, soldier-portable, laser-protective shield to provide protection and enhance solider lethality on the modern battlefield. The shield will utilize a combination of broad-spectrum light absorbing material, advanced heat spreading technologies, a novel solid-state phase change thermal energy storage material, and an insulating layer. This structure will be designed to effectively absorb incoming laser energy to avoid damage from reflection, rapidly distribute heat laterally to limit temperature rise at the point under irradiation, store large quantities of thermal energy via latent energy storage to minimize temperature rise across the structure and protect the points of contact with the soldier from dangerous temperatures. The key innovation of the proposed shield is the utilization of metallic solid-solid phase change material (SS-PCM) to absorb thermal energy without substantial rise in temperature. Specifically, we intend to use a NiTi alloy that undergoes a reversible, diffusionless crystallographic phase transition between 50 and 100 ░C that is capable of storing up to 34 J/g (nearly 240 MJm-3) of thermal energy. Utilizing only 1 kg of this material, all of the energy from a 500 W laser firing for 60 s can be stored without sensible heating. This phase change also results in changes in reflectivity and electrical conductivity, making it suitable for integration with sensors to detect incident laser strikes. Preliminary modeling indicates our proposed structure exceeds the requirements to withstand 100 W/cm2 incident radiation at powers up to 500 W for 60 s without exposing the soldier to temperatures ? 44 ░C. Working closely with the Army and partners (see letters of support/commitment), a prototype composite will be designed, modeled and subcomponents will be tested under laser irradiation in Phase I. Subsequent Phases will focus on full-scale prototype fabrication with integrated sensors and consideration given to soldier-portability and combat readiness.