A creation of thermal logic circuit using metamaterial consisting of multiple chromic materials

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22394
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0301:Mechanics of materials, production engineering, design engineering, fluid engineering, thermal engineering, mechanical dynamics, robotics, aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: Okayama University
• Principal Investigator: Isobe Kazuma 岡山大学, 自然科学学域, 助教 (10880180)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: 熱放射 / 二酸化バナジウム / メタマテリアル / 熱スイッチ

Outline of Final Research Achievements

The metal-insulator transition, exhibited by vanadium dioxide (VO2), significantly affects the refractive index of VO2 depending on its temperature. In this study, multilayered thin films consisting of VO2 were proposed to create a thermal switch switching its emissivity over a broadband wavelength. Through numerical simulations, the multilayered film exhibited a suitable switching property both for the sunlight absorption and radiative cooling depending on its temperature. Moreover, the multilayered thin film showed its potential to automatically control the radiative energy balance to keep its temperature constant without external power.

Free Research Field

熱工学

Academic Significance and Societal Importance of the Research Achievements

昨今，省エネルギー化やゼロ炭素といった，地球環境へ配慮した社会の実現へ向けた技術の開発が急務とされている．本研究の主眼である熱スイッチや論理回路は，人類の快適な生活に不可欠な温熱環境を，周囲の環境に応答して外部動力を必要とせずに自律制御する技術である．本研究では，特に光やふく射が関わる熱の授受を周囲温度によって制御することに注力した．結果として，理論的にではあるが地表面の温度に強く影響する太陽光の吸収量と放射冷却の強度を同時に操る機能性複合材料を提案するに至り，今後の実証実験へ向けた足がかりを築くことができた．