Direction‐Selective Energy Control Using Thermal Lens

J Juyeong Nam (Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea) I Injoong Chang (Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea) J Joon‐Soo Lim (Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea) J Jaehyeong Kim (Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea) J Jinsup Song (Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea) H Hyung Hee Cho (Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea)

Abstract

Abstract Directional energy control is a critical requirement for applications involving adaptive thermal management, infrared (IR) signature suppression, and multiband optical modulation. Herein, a directional energy control surface (DECS) is introduced that achieves passive, refraction‐based directional energy manipulation across visible and IR bands without requiring external power input. The DECS comprises three key layers: The directional control layer (DCL), composed of a thermal lens array, facilitates direction‐selective refraction, enabling real‐time control over radiative signatures. The IR control layer (IRCL), featuring an Au/quartz pattern, modulates IR emissivity. Finally, the visible coloration layer (VCL) enables adjustable optical reflection in the visible band. Experiments demonstrate that the DECS enables periodic, direction‐selective modulation of thermal and optical signatures, enhancing or suppressing radiance effectively depending on the detection angle. Extending the experimental evaluation to 3D wedge geometries confirms that the DECS can maintain its directional control capability in complex environments. These results establish the DECS as a scalable and energy‐efficient solution for directional energy control across multibands, offering a new paradigm for passive spectral and angular energy regulation. Thus, this study can facilitate the development of next‐generation energy‐controlling surfaces with potential applications in thermal camouflage, radiative cooling, energy‐efficient coatings, and dynamic optical management.

Article Details

Volume / Issue Vol. 38, Issue 5
Published January 01, 2026
ISSN 0935-9648
Publisher Unknown Publisher

Journal Info

Advanced Materials

Unknown Publisher

ISSN: 0935-9648 Physical Sciences

Authors (6)

J

Juyeong Nam

Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea

I

Injoong Chang

Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea

J

Joon‐Soo Lim

Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea

J

Jaehyeong Kim

Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea

J

Jinsup Song

Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea

H

Hyung Hee Cho

Department of Mechanical Engineering Yonsei University 50 Yonsei‐ro Seodaemun‐gu Seoul 03722 South Korea