Nanophotonic metasurface for a novel thermal management system*

Electricity is pivotal to modern human civilization, powering different devices used in houses, business and industry. However, the most reliable source of electricity generation has been fossil fuel, which generates greenhouse gases leading to global warming. Indoor temperature regulation alone accounts for half the electricity use in US, making it the largest expense in the country. Therefore, a photonic platform that can regulate household temperature autonomously depending on ambient temperature without the use of electricity is the need of the hour. In this work, we present a passive nanophotonic thermostat based on VO2 thin films, capable of self-adjusting its absorptivity and emissivity to maintain a set temperature approximately locked within the phase transition regions. The experimental results demonstrate that the structured metasurface sample reflects most of the incident IR radiation during high temperature operation and absorbs most of it during low temperature conditions, exhibiting promising characteristics needed to realize a passive temperature regulation. This work would open further avenues for research such as artificial thermal skin for personal temperature regulation, thermal sensing and could solve critical challenges in radiative heat emergent phenomena.