Thermal Diode Films with Liquid Crystal Elastomer Microstructures

Thermal diodes enabling asymmetric heat flow via efficiently conducting heat in one direction while blocking it in the opposite direction have great potential for controlling and managing thermal energy. Here, a thermal diode film with a scalable and thin‐film form factor is presented, which utilize...

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Main Authors: Jae Yun Baek, Gilyong Shin, Ju Hwan Lee, Sungryul Yun, Jei Gyeong Jeon, Tae June Kang
Format: Article
Language:English
Published: Wiley-VCH 2025-06-01
Series:Small Structures
Subjects:
Online Access:https://doi.org/10.1002/sstr.202400558
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author Jae Yun Baek
Gilyong Shin
Ju Hwan Lee
Sungryul Yun
Jei Gyeong Jeon
Tae June Kang
author_facet Jae Yun Baek
Gilyong Shin
Ju Hwan Lee
Sungryul Yun
Jei Gyeong Jeon
Tae June Kang
author_sort Jae Yun Baek
collection DOAJ
description Thermal diodes enabling asymmetric heat flow via efficiently conducting heat in one direction while blocking it in the opposite direction have great potential for controlling and managing thermal energy. Here, a thermal diode film with a scalable and thin‐film form factor is presented, which utilizes thermal contact asymmetry that varies with the direction of heat flow. The proposed thermal diode film is fabricated using two liquid crystal elastomer (LCE) layers separated by an air gap: one surface has a pillar structure, and the other has a hexagonal honeycomb structure. In forward mode, heating the LCE layer with the hexagonal honeycomb structure causes the sidewalls to buckle and contact the pillar structure on the opposite side, facilitating efficient conductive heat transfer. In reverse mode, heating the LCE layer with a pillar structure causes it to contract, increasing the gap between the layers with the pillar and hexagonal structures. This increased gap reduces convective heat transfer across the air gap. The thermal contact asymmetry, depending on the direction of heat flow, enables the film to achieve a thermal rectification ratio of ≈2.0 over a wide temperature range of 60–100 °C.
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spelling doaj-art-83625ce4daec4f4ba79f1cbe85736fdd2025-08-20T02:32:29ZengWiley-VCHSmall Structures2688-40622025-06-0166n/an/a10.1002/sstr.202400558Thermal Diode Films with Liquid Crystal Elastomer MicrostructuresJae Yun Baek0Gilyong Shin1Ju Hwan Lee2Sungryul Yun3Jei Gyeong Jeon4Tae June Kang5Department of Mechanical Engineering Inha University 100 Inha‐ro, Michuhol‐gu Incheon 22212 South KoreaDepartment of Mechanical Engineering Inha University 100 Inha‐ro, Michuhol‐gu Incheon 22212 South KoreaDepartment of Mechanical Engineering Inha University 100 Inha‐ro, Michuhol‐gu Incheon 22212 South KoreaTangible Interface Creative Research Section Electronics and Telecommunications Research Institute (ETRI) 218 Gajeong‐ro, Yuseong‐gu Daejeon 34129 South KoreaInstitute of Advanced Composite Materials Korea Institute of Science and Technology 92 Chudong‐ro, Bongdong‐eup Wanju‐gun Jeollabuk‐do 55324 Republic of KoreaDepartment of Mechanical Engineering Inha University 100 Inha‐ro, Michuhol‐gu Incheon 22212 South KoreaThermal diodes enabling asymmetric heat flow via efficiently conducting heat in one direction while blocking it in the opposite direction have great potential for controlling and managing thermal energy. Here, a thermal diode film with a scalable and thin‐film form factor is presented, which utilizes thermal contact asymmetry that varies with the direction of heat flow. The proposed thermal diode film is fabricated using two liquid crystal elastomer (LCE) layers separated by an air gap: one surface has a pillar structure, and the other has a hexagonal honeycomb structure. In forward mode, heating the LCE layer with the hexagonal honeycomb structure causes the sidewalls to buckle and contact the pillar structure on the opposite side, facilitating efficient conductive heat transfer. In reverse mode, heating the LCE layer with a pillar structure causes it to contract, increasing the gap between the layers with the pillar and hexagonal structures. This increased gap reduces convective heat transfer across the air gap. The thermal contact asymmetry, depending on the direction of heat flow, enables the film to achieve a thermal rectification ratio of ≈2.0 over a wide temperature range of 60–100 °C.https://doi.org/10.1002/sstr.202400558asymmetric heat transferbuckling of hexagonal honeycombsliquid crystal elastomersthermal diodesthermal energy managementthermal rectifications
spellingShingle Jae Yun Baek
Gilyong Shin
Ju Hwan Lee
Sungryul Yun
Jei Gyeong Jeon
Tae June Kang
Thermal Diode Films with Liquid Crystal Elastomer Microstructures
Small Structures
asymmetric heat transfer
buckling of hexagonal honeycombs
liquid crystal elastomers
thermal diodes
thermal energy management
thermal rectifications
title Thermal Diode Films with Liquid Crystal Elastomer Microstructures
title_full Thermal Diode Films with Liquid Crystal Elastomer Microstructures
title_fullStr Thermal Diode Films with Liquid Crystal Elastomer Microstructures
title_full_unstemmed Thermal Diode Films with Liquid Crystal Elastomer Microstructures
title_short Thermal Diode Films with Liquid Crystal Elastomer Microstructures
title_sort thermal diode films with liquid crystal elastomer microstructures
topic asymmetric heat transfer
buckling of hexagonal honeycombs
liquid crystal elastomers
thermal diodes
thermal energy management
thermal rectifications
url https://doi.org/10.1002/sstr.202400558
work_keys_str_mv AT jaeyunbaek thermaldiodefilmswithliquidcrystalelastomermicrostructures
AT gilyongshin thermaldiodefilmswithliquidcrystalelastomermicrostructures
AT juhwanlee thermaldiodefilmswithliquidcrystalelastomermicrostructures
AT sungryulyun thermaldiodefilmswithliquidcrystalelastomermicrostructures
AT jeigyeongjeon thermaldiodefilmswithliquidcrystalelastomermicrostructures
AT taejunekang thermaldiodefilmswithliquidcrystalelastomermicrostructures