Experimental demonstration of dynamic thermal regulation using vanadium dioxide thin films

Ahmed M Morsy,Philip W C Hon,Vladan Jankovic,Mark W Knight,Michael T Barako,Luke A Sweatlock,Georgia T Papadakis,Michelle L Povinelli,Virginia D Wheeler

doi:10.1038/s41598-020-70931-0

Abstract

We present an experimental demonstration of passive, dynamic thermal regulation in a solid-state system with temperature-dependent thermal emissivity switching. We achieve this effect using a multilayered device, comprised of a vanadium dioxide (VO2) thin film on a silicon substrate with a gold back reflector. We experimentally characterize the optical properties of the VO2 film and use the results to optimize device design. Using a calibrated, transient calorimetry experiment we directly measure the temperature fluctuations arising from a time-varying heat load. Under laboratory conditions, we find that the device regulates temperature better than a constant emissivity sample. We use the experimental results to validate our thermal model, which can be used to predict device performance under the conditions of outer space. In this limit, thermal fluctuations are halved with reference to a constant-emissivity sample.

Highlights

We present an experimental demonstration of passive, dynamic thermal regulation in a solid-state system with temperature-dependent thermal emissivity switching
We present an experimental method for studying dynamic thermal regulation due to infrared emissive switching
We have directly demonstrated dynamic, passive thermal regulation via experiments on a V O2 phase-change device

Summary

Introduction

We present an experimental demonstration of passive, dynamic thermal regulation in a solid-state system with temperature-dependent thermal emissivity switching. We achieve this effect using a multilayered device, comprised of a vanadium dioxide ( VO2) thin film on a silicon substrate with a gold back reflector. One interesting application of emissive control is the design of materials that self-regulate their temperature[8,9], a property we term thermal homeostasis[10,11] Such a capability is likely to be useful for a variety of applications including satellite thermal control, for which traditional solutions require either electrical power or moving p arts[12,13,14,15]. It was found that the growth technique influences the optical properties due to the quality of the thin crystalline films[27]

Methods

Discussion

Conclusion