Thermal Sensing and Responsive Materials for Environmental Monitoring

Many ordnance materials such as Hexogen (RDX) and Octogen (HMX) are stabilized by additives such as trinitrotoluene (TNT), wax, plasticizers, and polymers (as in plastic bonded explosives, PBX) to offer greater chemical stability, lowered shock sensitivity, and greater thermal stability to the compositions. However, exposure of these improved compositions to environmental conditions outside of the design range can degrade these additives leading to unstable, precarious explosive materials. Currently, it is difficult if not impossible to track the thermal history (or temperature dose) of ordnance materials; critical information needed to avoid these deadly accidents. In this proof-of-concept effort, we propose a viable solution to this issue through the development of a pliable, no-power technology capable of visibly indicating in real-time the current temperature range of a device or an environment, the temperature dose (or temperature history) that device or environment has experienced, and whether or not critical threshold temperatures have been exceeded.