Fluid Control of Radiation

Student’s name: Jonah Gezelter Home Institution: Case Western Reserve University NNCI Site: CNS @ Harvard University REU Principal Investigator: Dr. Joanna Aizenberg – Department of Materials Science and Department of Chemistry and Chemical Biology, Harvard University REU Mentor: Raphael Kay- Department of Materials Science, Harvard University Abstract: With a myriad of factors contributing to heat flux to buildings (solar heating, ground temperature, occupancy, etc.), buildings are consistently exposed to a wide variety of thermal scenarios, throughout both the day and year [1]. However, these scenarios are not always the ideal condition for building inhabitants. In these non-ideal scenarios, buildings need to control how heat is flowing into or out of the building. Currently this is done with insulating layers to isolate the interior spaces, and heaters and coolers to control indoor temperature. However, these heaters and coolers require exorbitant amounts of energy to maintain temperature differences between the building interior and its external environment. In addition to the heating and cooling, building occupants also have energy drawn from lighting the space that they inhabit. To limit the required energy consumption of such buildings working to maintain a comfortable temperature and lighting level, this project presents a novel way of fine-tuning energy flux of light and thermal radiation. By incorporating multiple fluidic layers, where injected fluids in spaces within glass window panes can control different wavelength ranges, this device can control visible, near-infrared, and mid-infrared light independently. This work also focuses on the fabrication of a reflective surface for mid-infrared light which can be blocked by an absorbing fluid to create a switchable control for mid-infrared radiation. This surface was made by creating rugate filters using electrochemical etching techniques and chemical vapor deposition to create both effective and real changes in index of refraction, forcing a strong reflection of a chosen wavelength.