Updated on 2026/04/27

Information

 

写真a

 
YOO DONGHYEON
 
Organization
International Institute for Carbon-Neutral Energy Research Advanced Energy Conversion Systems Thrust Associate Professor
Title
Associate Professor
Contact information
メールアドレス
Tel
092-802-6718

Research Areas

  • Energy Engineering / Earth resource engineering, Energy sciences

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Thermal engineering

Degree

  • Ph.D. in Mechanical Engineering ( 2021.8 )

  • B.S. in Mechanical Engineering ( 2015.2 )

Research History

  • Kyushu University, International Institute for Carbon-Neutral Energy Research (I2CNER)   

    2026.4 - Present

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    Country:Japan

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  • University of Illinois Urbana and Champaign (UIUC) Mechanical Science and Engineering  

    2023.12 - 2025.11

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    Country:United States

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  • Pohang University of Science and Technology (POSTECH) Mechanical Engineering  

    2021.9 - 2023.11

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    Country:Korea, Republic of

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Research Interests・Research Keywords

  • Research theme: Liquid-based energy harvesting

    Keyword: Liquid-solid contact electrification

    Research period: 2015.3 - Present

  • Research theme: Heat transfer

    Keyword: Two-phase cooling

    Research period: 2022.12 - Present

  • Research theme: Precision Surface Structuring

    Keyword: Anodizing Process

    Research period: 2022.12 - Present

  • Research theme: Biomimetic Design

    Keyword: Biomimetic Design

    Research period: 2026

  • Research theme: Micro and Nanoscale Surface Engineering

    Keyword: Micro and Nanoscale Surface Engineering

    Research period: 2026

  • Research theme: Liquid-solid contact electrification

    Keyword: Liquid-solid contact electrification

    Research period: 2026

  • Research theme: Heat transfer

    Keyword: Heat transfer

    Research period: 2026

Awards

  • Oral session, Grand Prize

    2025.6   The Korean Institute of Electrical and Electronic Material Engineers  

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  • Poster session, Grand Prize

    2023.6   The Korean Institute of Electrical and Electronic Material Engineers  

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  • The Best Poster Award, Grand Prize

    NANO KOREA 2023 Organizing Committee  

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Papers

  • Toward Droplet Energy Harvesting in Harsh Environment: Mechanical Buckling‐Induced 3D Structured Droplet‐Based Electricity Multigenerator

    Dongik Kam, Hyeonyeong Choi, Girak Gwon, Sunmin Jang, Soban Ali Shah, Donghyeon Yoo, Dongwhi Choi

    Small   21 ( 25 )   2025.5   ISSN:1613-6810 eISSN:1613-6829

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    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    Abstract

    Opening new horizons for droplet‐based energy harvesters, droplet‐based electricity generators (DEGs) face several obstacles, such as deficient current output and vulnerability to the external environment. In this study, a droplet‐based electricity multigenerator (DEMG) subserved by an electromagnetic generator (EMG) is proposed to tackle them. By introducing a mechanical buckling‐induced 3D structure, the DEMG is designed to have a sufficiently high figure of merit for flexibility/elasticity to harvest electric energy from droplets. Thanks to the hybrid effect of EMG, the total amount of induced charge from DEMG is enhanced by more than 8809% compared with that from DEG only. Furthermore, a continuous energy supply is expected from DEMG even under dusty and humid conditions. This study not only provides a pathway to overcome the inherent limitations of conventional DEGs but also paves the way for efficient droplet energy harvesting technologies applicable in diverse environmental conditions.

    DOI: 10.1002/smll.202502717

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  • Tailoring dielectric constant via anodic aluminum oxide-based nanoparticle for boosting the output performance of a triboelectric nanogenerator

    Dongik Kam, Girak Gwon, Donghyeon Yoo, Jaehyeong Kim, Hyeokchan Gwon, Moonwoo La, Sung Jea Park, Dongwhi Choi

    Chemical Engineering Journal   500   157123 - 157123   2024.11   ISSN:1385-8947

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.cej.2024.157123

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  • Beyond Metallic Electrode: Spontaneous Formation of Fluidic Electrodes from Operational Liquid in Highly Functional Droplet‐Based Electricity Generator

    Sunmin Jang, Soban Ali Shah, Jaehyun Lee, Sumin Cho, Dongik Kam, Yoonsang Ra, Donghan Lee, Muhammad Ramzan Khawar, Donghyeon Yoo, Awais Ahmad, Dongwhi Choi

    Advanced Materials   36 ( 35 )   2024.7   ISSN:0935-9648 eISSN:1521-4095

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    Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    Abstract

    The droplet‐based electricity generator (DEG) has facilitated efficient droplet energy harvesting, yet diversifying its applications necessitates the incorporation of various to the DEG. This study first proposes a methodology for advancing the DEG by substituting its conventional metallic electrode with electrically conductive water electrode (WE), which is spontaneously generated during the operation of the DEG with operating liquid. Due to the inherent conductive and fluidic nature of water, the introduction of the WE maintains the electrical output performance of the DEG while imparting functionalities such as high transparency and flexibility. So, the resultant WE applied DEG (WE‐DEG) exhibits high optical transmittance (≈99%) and retains its electricity‐generating capability under varying deformations, including bending and stretching. This innovation expands the versatility of the DEG, and especially, a sun‐raindrop dual‐mode energy harvester is demonstrated by hybridizing the WE‐DEG and photovoltaic (PV) cell. This hybridization effectively addresses the weather‐dependent limitations inherent in each energy harvester and enhances the temperature‐induced inefficiencies typically observed in PV cells, thereby enhancing the overall efficiency. The introduction of the WE will be poised to catalyze new developments in DEG research, paving the way for broader applicability and enhanced efficiency in droplet energy harvesting technologies.

    DOI: 10.1002/adma.202403090

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  • Toward Commercialization of Mechanical Energy Harvester: Reusable Triboelectric Nanogenerator Based on Closed-Loop Mass Production of Recyclable Thermoplastic Fluoropolymer with Microstructures

    Yoonsang Ra, Jong Hyun Lee, Jiho Bang, Donghan Lee, Dongik Kam, Sumin Cho, Sunmin Jang, Donghyeon Yoo, Jong Woo Kim, Kyoung Je Cha, Dongwhi Choi

    International Journal of Energy Research   2023.11   ISSN:1099-114X

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    Language:English   Publishing type:Research paper (scientific journal)  

    <jats:p>Triboelectric nanogenerators (TENGs) have been considered a promising energy harvester. However, the wear-induced limited lifetime of the surface structure on fluoropolymeric contact layers of the TENG has been a critical issue in its commercialization because surface structures on soft engineering materials play a key role in enhancing the generation of electricity in TENGs. After the surface structure on the polymeric contact layer is worn out, the layer is required to be replaced with a new one with intact surface structures to reenhance the degraded output performance of the TENG. Herein, injection molding-assisted mass production is applied to manufacture micro/nanoscale surface-structured perfluoroalkoxy alkane (PFA) contact layers, which exhibit easily replaceable but fully recyclable characteristics. The optimized production time is shorter than 1 min, and the unit cost under $1 of manufacturing surface-structured PFA contact layers is achieved. TENG with the fabricated PFA contact layer can generate over 620 V of voltage and up to 12.4 mW of power from solid-solid contact and separation when the contact area is <jats:inline-formula>
    <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1">
    <mn>5</mn>
    <mtext> </mtext>
    <mtext>cm</mtext>
    <mo>×</mo>
    <mn>5</mn>
    <mtext> </mtext>
    <mtext>cm</mtext>
    </math>
    </jats:inline-formula> and the contact frequency is 10 Hz. The manufactured PFA contact layer can be facilely replaced with a new one before the end of its lifetime to maintain the electrical output of the TENG, and the postused one can be fully recycled via reprocessing as the material for injection molding. Consequently, a tile-floor-based TENG is proposed as a proof-of-concept demonstration to show environmentally friendly and closed-loop production of TENGs.</jats:p>

    DOI: 10.1155/2023/6919663

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  • Advancing Energy Harvesting Efficiency from a Single Droplet: A Mechanically Guided 4D Printed Elastic Hybrid Droplet‐Based Electricity Generator

    Dongik Kam, Girak Gwon, Sunmin Jang, Donghyeon Yoo, Sung Jea Park, Moonwoo La, Dongwhi Choi

    Advanced Materials   2023.11   ISSN:0935-9648

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    Language:English   Publishing type:Research paper (scientific journal)  

    <jats:title>Abstract</jats:title><jats:p>A droplet possesses the ubiquity and potential to harvest a vast amount of energy. To exploit droplets effectively, a novel output enhancement strategy that can coexist and create synergy with the recently studied droplet‐based electricity generator (DEG) and material/surface structure modification must be investigated. In this study, a mechanical buckling‐based 4D printed elastic hybrid droplet‐based electricity generator (HDEG) consisting of a DEG and solid–solid triboelectric nanogenerator (S–S TENG) is first presented. During the electricity generation process of the DEG by droplet impact, the HDEG structure, which is merged via a simple 4D printing technique, permits the conversion of dissipated energy into elastic energy, resulting in an S–S TENG output. The HDEG outputs are naturally integrated owing to the simultaneous activation of a single droplet, resulting in an approximately 30% improvement over the output of a single DEG. Internal and external parametric studies are performed as HDEG design guidelines. The HDEG exhibits a 25% better energy supply performance than that of a single DEG, demonstrating its applicability as a power source. This research proposes the way toward a hybrid system that efficiently harvests energy from ubiquitous droplets.</jats:p>

    DOI: 10.1002/adma.202303681

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  • A Liquid Triboelectric Series

    Donghyeon Yoo, Sunmin Jang, Sumin Cho, Dongwhi Choi, Dong Sung Kim

    Advanced Materials   2023.6   ISSN:0935-9648

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    Language:English   Publishing type:Research paper (scientific journal)  

    <jats:title>Abstract</jats:title><jats:p>The triboelectric series is a generally accepted method for describing the triboelectric effect. It provides a way to control the double face of the ubiquitous triboelectric effect: causes of unpredictable accidents and the resultant surface charge as energy sources. However, previous studies have been biased in solids despite being observed in liquids (liquid‐solid contact electrification). Therefore, a liquid triboelectric series is necessary to be established to manipulate the liquid triboelectric effect according to the appropriate goal. In this study, a liquid triboelectric series is first established to describe the triboelectric properties of each liquid when contact electrification occurs with a solid surface. The liquid triboelectric series covers electrolytes, organic solvents, oxidants, and higher sugar alcohols. Common chemical groups can be derived from the liquid triboelectric series that hydroxyl groups enhance, and benzene groups suppress the liquid triboelectric effect. The results are demonstrated by the amplified efficiency of an energy harvester and particle contamination after surface washing. This study will play a pivotal role in understanding the liquid‐solid contact electrification phenomenon and providing new perspectives on the applications of the liquid triboelectric effect.</jats:p>

    DOI: 10.1002/adma.202300699

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  • Lotus leaf-inspired droplet-based electricity generator with low-adhesive superhydrophobicity for a wide operational droplet volume range and boosted electricity output

    Donghyeon Yoo, See Jo Kim, Yoonsu Joung, Sunmin Jang, Dongwhi Choi, Dong Sung Kim

    Nano Energy   2022.8   ISSN:2211-2855

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.nanoen.2022.107361

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  • Enhanced surfaces manufactured using pulsed laser texturing for highly efficient two-phase cooling Reviewed International journal

    Roni, MRH; Shatskiy, E; Aflatounian, S; Dewanjee, S; Gregorcic, P; Ganesan, V; Yoo, D; Yang, CM; Braun, PV; Nawaz, K; Miljkovic, N

    APPLIED THERMAL ENGINEERING   288   2026.3   ISSN:1359-4311 eISSN:1873-5606

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.applthermaleng.2025.129497

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  • Electrostatically Self‐Powered Intelligent Force Sensor With Tunable Performance via Mechanically Guided <scp>3D</scp> Morphing

    Dongik Kam, Dayeon Jang, Hee Jae Hwang, Sunmin Jang, Sumin Cho, Donghan Lee, Donghyeon Yoo, Junsang Yoon, Seong Jin Lee, Jongwoo Kim, Kyoung Je Cha, Dongwhi Choi

    EcoMat   8 ( 2 )   2026.2   ISSN:2567-3173 eISSN:2567-3173

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    Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    ABSTRACT

    Sensors that capture diverse environmental information are crucial in the elemental technology driving the Fourth Industrial Revolution. However, the trade‐off between sensitivity and working range exhibited by conventional sensors results in limitations when the target stimuli deviate from their predesigned specifications. Thus, single sensors with adjustable performance characteristics must be developed to satisfy functionality requirements in diverse environments. In this study, a Tunable Usability‐Nourished Electrostatic‐based self‐powered force sensor (TUNE sensor) is introduced to overcome the limitations of the fixed detection performance of a single sensor. The tunable sensing performance of the TUNE sensor is achieved via mechano‐guided geometrical adaptation of its three‐dimensional (3D) structure formed via mechanical buckling. Continuous and reversible shape changes in the 3D structure allow modulation of the stiffness of the TUNE sensor, resulting in tunable sensing performance (sensitivity of 0.53~1.08 nC/N and working range of 1.01~0.35 N). The effectiveness of the tunable sensing performance is demonstrated through its implementation in a reconfigurable electronic scale and robotic sensing. This mechano‐guided geometrical adaptation strategy offers the potential for extending the use of sensors in multivariate environments and providing new opportunities for intelligent sensing systems in various applications.

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    DOI: 10.1002/eom2.70048

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    Other Link: https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eom2.70048

  • A hybrid mechanical-electrostatic separator for oil-refrigerant separation Reviewed International journal

    Vivek S. Garimella, Donghyeon Yoo, Tarek Gebrael, Haoyun Qiu, Syed Angkan Haider, Mostafa Olyaei, Muhammad Jahidul Hoque, Alex D. Patel, Willem A. Alleyne, John Brownridge, Nenad Miljkovic

    Applied Thermal Engineering   277   2025.10   ISSN:1359-4311 eISSN:1873-5606

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Applied Thermal Engineering  

    In the United States, water heating, space heating, and space cooling account for 49 % of energy consumption in buildings (residential and commercial). Most space cooling needs and a small portion of space heating needs are met using electrically driven vapor-compression systems. Adequate lubrication of the compressor within these vapor-compression systems is a critical factor in maintaining compressor performance and lifetime. However, oil transport from the compressor to other components in the system can lower the heat transfer coefficient and increase pressure drop. To mitigate this, most compressors rely on coalescing oil separators to separate oil from the refrigerant stream. These oil separators suffer from reduced separation efficiency at high refrigerant mass flow rates. To counter the separation efficiency reduction requires denser and heavier meshes to trap more oil droplets, further decreasing system energy and power densities and increasing pressure drop. Electrostatic separation has been explored as an alternative technology to leverage the tribocharging of oil droplets as they flow through the system. However, these electrostatic parallel-plate systems can be complex. This study demonstrates a hybrid approach to separation of oil from refrigerant by introducing an electric field to traditional coalescing oil separators to capture oil at a higher efficiency and reduce the number of mesh nodes required, ultimately reducing pressure drop. Experimentally, we demonstrate an increase in separation efficiency by a factor up to 7× in the hybrid system when compared to a system with no applied electric field past a critical value for electric field intensity, with a possible 3× reduction in pressure drop—leading to a 1 % enhancement in coefficient of performance. Insights for implementation of this technology into a real HVAC system are also found, such as the limiting behavior in separation efficiency at higher field intensities at a given constant flow rate. The electrostatic separation technology shows significant promise to improve both system performance and lifetime of new and existing vapor-compression systems, increasing the energy density, power density, and heat transfer coefficient of the system while simultaneously lowering their labor cost and carbon footprint of maintenance and replacement.

    DOI: 10.1016/j.applthermaleng.2025.127129

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  • Advances in 3D-printed triboelectric nanogenerators and supercapacitors for self-sustainable energy systems

    Sumin Cho, Muhammad Ramzan Khawar, Yoonsang Ra, Sunmin Jang, Donghan Lee, Dongik Kam, Soban Ali Shah, Donghyeon Yoo, Yasir Javed, Awais Ahmad, Younghoon Lee, Hee Jae Hwang, Chengkuo Lee, Dongwhi Choi

    Materials Today   85   189 - 211   2025.6   ISSN:1369-7021

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.mattod.2025.02.010

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  • Nanostructuring of Additively Manufactured Stainless-Steel Surfaces for Superior Boiling Heat Transfer Reviewed International journal

    Thukral, TS; Nie, YH; Arissi, G; Honeyville, AMK; Yoo, D; Dewanjee, S; Braun, PV; Charpagne, M; Miljkovic, N

    NANO LETTERS   25 ( 15 )   6276 - 6283   2025.4   ISSN:1530-6984 eISSN:1530-6992

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Nano Letters  

    While stainless steel offers unique advantages for thermal applications in corrosive environments, it is resilient to traditional nanostructuring techniques such as chemical etching for heat transfer augmentation. In this work, we fabricate a 304L stainless steel alloy using directed energy deposition additive manufacturing, which leads to a metastable microstructure state that facilitates efficient and scalable etching using chloride species. We unveil a two-step etching mechanism that results in the formation of a network of micro- and nanoscale surface structures. This structured surface shows a 5-fold enhancement of the heat transfer coefficient at significantly lower superheat during pool boiling of water, attributed to increased nucleation in suitably sized cavities created by etching. Our work illustrates the vast potential of advances in additive manufacturing techniques for the development of highly efficient and compact thermal systems.

    DOI: 10.1021/acs.nanolett.5c01026

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  • Recent Progress in Strain-Engineered Stretchable Constructs

    Adeela Hanif, Donghyeon Yoo, Dohui Kim, Farid Mustafayev, Sarkhan Hajiyev, Dong Sung Kim

    International Journal of Precision Engineering and Manufacturing-Green Technology   2023.9   ISSN:2288-6206

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s40684-023-00565-w

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Presentations

  • Lotus leaf-based biomimetic droplet electricity generator

    Donghyeon Yoo, See Jo Kim, Yoonsu Jong, Sunmin Jang, Dongwhi Choi, Dong Sung Kim

    2022.10 

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    Event date: 2022.10

    Presentation type:Oral presentation (general)  

    File: 20221028_AMSM.pdf

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  • Hybrid photovoltaic-triboelectricnanogeneratorwith a moth-eye mimicking surface structure

    Donghyeon Yoo, Seung-Chul Park, Dongwhi Choi, Hyuneui Lim, Dong Sung Kim

    he 20th International Nanotechnology Symposium & Exhibition  2022.7 

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    Event date: 2022.7

    Presentation type:Oral presentation (general)  

    File: 20220722_NanoKorea.pdf

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Academic Activities

  • Kick-off Meeting for the STEAM Research Project RFP Committee (2022)

    Role(s): Planning/Implementing academic research

    Korea Institute of Science and Technology (KIST)  2022.2

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    Type:Scientific advice/Review 

    File: STEAM Research Project RFP Committee.pdf

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