10.25394/PGS.8049851.v1 Collier S Miers Collier S Miers Thermal Metrology for Waste Heat Systems: Thermoelectrics to Phase Change Materials Purdue University Graduate School 2020 Thermoelectrics Z-Meter High-Temperature Phase Change Material Passive Thermal Management Engineering Instrumentation Heat and Mass Transfer Operations Mechanical Engineering 2020-06-25 17:59:33 Thesis https://hammer.purdue.edu/articles/thesis/Thermal_Metrology_for_Waste_Heat_Systems_Thermoelectrics_to_Phase_Change_Materials/8049851 This dissertation presents the development of two unique measurement platforms. <br><br>The first system is a high-temperature Z-Meter. This system is designed to simultaneously measure the electrical resistivity, Seebeck coefficient, and thermal conductivity of a thermoelectric sample to accurately determine the figure of merit, ZT, for that material. It is designed to operated at sample temperatures of up to 1000C, and with temperature gradients on the order of 500C across the sample. This system also provides <i>in situ</i> load monitoring for contact pressure and allows the user to adjust loading during the experiment. <br><br>The second part of this dissertation focuses on the development of enhanced composite phase change material (PCM) heat sinks to improve passive thermal management in mobile electronics. We present a new design for a composite PCM heat sink and utilize off-the-shelf PCMs to show characterize the performance. In order to accurately investigate the performance enhancement of these designs, we develop a turn-key thermal management evaluation platform to allow the user complete control over the power profiles and cycling applied to the test chip, as well as providing <i>in situ</i> temperature monitoring within the chip. The proposed package designs show significant improvement in the length of time extended before reaching the cut-off temperature within the heatfluxes tested, 6 - 14 W/cm^2, and accomplish this while weighing less than the equivalent sensible heat storage design.<br><br><br><br>