September 14
@
2:00 PM
–
3:00 PM
Radiative Thermal Control of Spacecraft using Thermochromic Infrared Materials
Abstract: Thermochromic infrared surfaces have temperature-dependent emissivity spectra that enable radiators to respond to changes in the thermal environment. Spacecraft can leverage this unique behavior for autoregulating thermal control, where thermochromic surfaces are designed to passively transition between a high thermal emissivity (to radiate heat when hot) and a low thermal emissivity (to retain heat when cold). In this talk, we introduce the materials, methods, and analyses of Variable Emissivity Materials (VEMs) using thermal objectives, where spectral infrared engineering is used to achieve passive control over temperature and heat flux. We show how the models and materials are validated calorimetrically and describe a novel set of thermo-optic characteristics used in both the design and system modeling of VEMs. Finally, we present an optimization perspective for further development of VEMs for thermal control.
Bio: Dr. Max R. Lien is a research scientist focused on developing optical materials and photonics for national security applications. He earned a Bachelor of Science from the University of Wisconsin–Madison in 2019, followed by a Master of Science in 2021 and a Doctor of Philosophy in 2023 from the University of Southern California, all in electrical engineering. Currently, Dr. Lien is a Principal Research Scientist in the basic research laboratories at Northrop Grumman in Redondo Beach, California, where he oversees a portfolio of advanced material development and leads research collaborations with academic partners. Previously, he was a Visiting Technologist at the NASA Jet Propulsion Laboratory working on mid-infrared optics for compact hyperspectral imagers.