Passive functionalized thermal emitter based on metal-insulator transition composite materials. – PassiveHEAT
Managing the heat generated in solid materials is a challenging problem for the development of numerous technologies (microelectronics, energy conversion systems, building thermal control, spacecraft thermal control…). Over 60% of energy that is used in industry is lost as low grade waste heat and developing innovative solutions to control this energy is of tremendous importance.
The PassiveHEAT project aims to propose new functionalized nanostructured coatings in order to control both the spectrum and the pattern (i.e. directivity and geometry) of the thermal emission by a simple change in their temperature without any external supplying in energy. Our approach is based on the combination of the properties of the phase transition materials, vanadium dioxide (VO2) with basic principles of the nanophotonics engineering.
The main objectives of the project PassiveHEAT are: 1. Better understand the mechanism of the radiative behavior of specific structures; 2.Conceive new passive thermal emitters and 3. Develop a metrology for the characterization of the thermal emitters.
VO2 is a metal-insulator transition material, which undergoes a reversible structural phase transition at a temperature of transition (TC) of 68°C associated with drastic changes in its dielectric permittivity. By combining the peculiar characteristics of MIT materials with the basic principles of the nanophotonics engineering we will explore several new functionalities. In particular we will conceive 3 types of thermal emitters:
a) Coatings with a negative or a positive differential emissivity (i.e. a thermal emission which decreases or increases with respect to the temperature around TC).
b) Radiative thermal switches able to work around a critical temperature
c) Thermal antenna with the orientation of lobes of emission which is driven by the temperature level.
These functionalized coatings could in particular pave the way for a fully passive cooling technology.
The project is organized into four workpackages (WP): WP1 – Design of functionalized emitters, WP2 – Material processing and micro-nanofabrication of the designed devices, WP3 – Experimental characterization of the devices. Finally a wokpackage will be devoted to the management and coordination of project.
This project proposes a new paradigm to control the thermal emission of a solid using nanostructured coatings base on phase-change materials. For this reason, it is placed at the boundary between several different domains of physics, all playing an important role in the theoretical and experimental investigations. Nanophotonics and thermal physics are relevant for a proper description of the thermal emission and the rational design of composite structure. Material sciences and nanotechnology will be fully exploited for the nanofabrication of the devices and finally the experimental characterization of coatings will require a deep knowledge in IR spectroscopy. The consortium gathers all this know-how and expertise to execute the PassiveHeat project with success.
Monsieur Etienne EUSTACHE (THALES RESEARCH & TECHNOLOGY)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
LCF Jean-Louis Charles Martin
CETHIL CENTRE D' ÉNERGÉTIQUE ET DE THERMIQUE DE LYON
TRT THALES RESEARCH & TECHNOLOGY
Help of the ANR 515,301 euros
Beginning and duration of the scientific project: February 2020 - 36 Months