Emissivity measurements with an Atomic Force Microscope

TL;DR

This paper introduces a novel method using functionalized micromechanical bilayer levers with an atomic force microscope to accurately measure radiative heat flux and emissivity at the microscale, demonstrating modulation of heat transfer during VO2 phase transition.

Contribution

The study presents a new technique for quantitative radiative heat flux measurement using AFM-based bilayer levers, enabling precise emissivity and temperature assessments at the microscale.

Findings

Good agreement with Stefan Boltzmann law

Radiative heat transfer modulated by a factor of 5 during VO2 phase transition

Method allows reversible control of heat flux between materials

Abstract

We show that functionalized micromechanical bilayer levers can be used as sensitive probes to accurately measure radiative heat flux in vacuum between two materials at the micro scale. By means of calibration to one material these measurements can be made quantitative for radiative heat flux or for either temperature or material emissivity. We discuss issues and opportunities for our method and provide ample technical details regarding its implementation and demonstrate good correspondence with the Stefan Boltzman law. We use this system to probe the phase transition of VO2 and find that radiative heat transfer in farfield between VO2 and glass can be reversibly modulated by a factor of 5.