Capacitive Sensing of Frost Growth Dynamics
I joined the Energy Transport Research Lab under Professor Nenad Miljkovic in 2022. This paper reflects the culmination of my first year there.
Frost buildup degrades thermal efficiency in HVAC systems, refrigeration, transportation, and cryogenics. Most systems use passive monitoring to trigger defrost cycles, which wastes energy through unnecessary or prolonged defrosting. We developed a novel capacitive sensing method that measures both frost thickness and density, enabling optimized defrost timing and reducing energy waste.
I was tasked with re-designing the experimental setup of the system to curate better data collection and let it run autonomously.
I started by automating control of the lab's LCR machine and chiller to increase experimental throughput throughout at all times without human intervention. To improve data quality, I helped replace the chiller with a solid-state heat pump and integrated continuous mass measurement with a mass scale. I also designed a secondary camera housing and tested various electrodes and surfaces.
The automated system enabled 5-hour uninterrupted experiments, which was necessary to be able to run experiments continuously and accurately detect changes. We achieved a sensitivity of 0.04 pF per 4g of frost significantly exceeding previous detection capabilities.