Temperature Sensors Embedded in Paint for Fire Debris Analysis and Arson Scene Investigations

As submitted by the proposer: Compared to many other forensic sciences, the scientific footing of fire investigations still lacks behind and there is plenty of room for improvements with the potential to more clearly identify the causes of a fire and avoid potential convictions based upon flawed evidence. The purpose of this project is to provide fire and arson scene investigators with a new tool for more reliable temperature measurements during fire testing/modeling and during forensic investigations. In particular, our goal is to demonstrate the feasibility of our temperature sensors, embedded in wall paint, as a means to measure and record temperature during fire events. This effort requires verification of the reliability, process development for sensor recovery, calibration for a range of temperatures and heating durations, identifying the effect of fire-fighting measures, testing at the ATF Fire Research Laboratory (Dr. David T. Sheppard), and comparison with fire modeling results. Since 2010 the PI and his research group have been engaged by the Defense Threat Reduction Agency to develop nanophase temperature sensors capable of measuring and recording the temperature inside explosions. The temperature sensors consist of wet-chemically synthesized precursors of luminescent particles. These particles are doped with rare-earth ions such as europium (Eu), which can emit fluorescent light. The specific spectral shape of the emission is indicative of the morphology of the nanoparticles. When exposed to heat, the precursors decompose and crystallize, transitioning from an amorphous compound into a crystalline compound, followed by grain growth. These morphological changes are reflected by changes in the optical spectra which can be correlated with the temperature. These nanophase temperature sensors have been successfully tested at the Naval Surface Warfare Center – Indian Head. This project contains a research and/or development component, as defined in applicable law. ca/ncf