
Dr. Justin (Junseok) Ma
Jang Young-Sil Postdoctoral Research Fellow
Korea
Advanced
Institute of
Science and
Technology
(KAIST)
Research Interests
- Liquid Crystals
- Optoelectronics
- Microwave & mmWave Devices
- Functional Materials
- Printing Technology
Education
- KAIST — Nature Sciences Research Institute — Postdoctoral Research Fellow Sep 2025 – Sep 2026 · Soft Material Assembly Group (SMA Group)
- University of Oxford — Recognised Student, Engineering Science (Keble College) Dec 2023 – Dec 2024 · Soft Matter Photonics Group(SMP Group) · My Profile
- POSTECH — Ph.D., Electrical Engineering Feb 2022 – Aug 2025 · Wave Arrays & Display Engineering Lab (WADE Group)
- POSTECH — M.S., Electrical Engineering Feb 2020 – Feb 2022 · Wave Arrays & Display Engineering Lab (WADE Group)
- POSTECH — B.S., Electrical Engineering Feb 2016 – Feb 2020
Professional Experience
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KAIST — National R&D Projects (Researcher)
- 6G Core Technology Development Program (IITP, Korea): Fast-switching reconfigurable intelligent surface (RIS) liquid-crystal antennas for next-generation wireless systems.
- Lightweight LC-based mmWave Beamforming Antenna System (ADD, Agency for Defense Development): Multi-purpose, lightweight LC beamforming antenna system for next-generation military communications and radar, mountable on missiles and mobile weapon platforms. Dec 2021 – Nov 2026 · Total investment: KRW 6.718B
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POSTECH — Project Lead, LC Printing for Smart Devices Feb 2025 – Present
- High-resolution, full-color smart windows for commercial display; banking structures for enhanced resolution and precise pattern formation.
- Extending printed LC to RF & optoelectronic devices for next-gen communication and optical systems.
- Developing an innovative fabrication method for liquid-crystal devices.
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University of Oxford — Project Lead, DoD Printing for Smart Windows Dec 2023 – Dec 2024
- Electrochromic LC systems with simultaneously controllable color & transmittance using Drop-on-Demand (DoD) printing.
- Printed, LC-based antennas/phased-array concepts; integrated advanced materials (push-pull azo, blue-phase) for optical & RF performance.
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Samsung Science & Technology Foundation — Researcher, CORE: Sub-THz 6G Sep 2021 – Sep 2024
- Characterization & fabrication of LCs for RIS optimized for D-band communication.
- LC-based tunable microwave/mmWave components for 6G networks.
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POSTECH & JNC Corporation (Japan) — Researcher, LC-based RF Applications & Commercialization Sep 2020 – Aug 2024
- Developed & optimized LC composites for microwave/mmWave (5G & satellite comms).
- Commercialized new LC mixtures with JNC Corporation (Japan) — incl. ZOC-A019XX (loss tangent ≈ 0.006; tunability ≈ 0.33 @ 28 GHz). Corporate Disclosure
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LG Display — Intern, Preliminary Research Team for OLED Jun 2018 – Aug 2018
- Researched advanced LCD/OLED technologies to support display innovation.
- Suggested process-efficiency strategies to improve manufacturing workflow.
Publications (20+)
Dissertations
- J. Ma, “A Study of Liquid Crystal-based Phase Shifter in the Millimeter-wave Range for Utilizing Current Mass-production Technology of Display Industry,” M.S. Thesis, Dept. of Electrical Engineering, POSTECH, Korea, 2021.
- J. Ma, “Development of Multifunctional Reconfigurable Liquid Crystal Devices Using Drop-on-Demand Printing,” Ph.D. Dissertation, Dept. of Electrical Engineering, POSTECH, Korea, 2025.
Journal Publications
- J. Ma+, D. Lee+, et al., “Low-Power Full-Color Printed Reflective Liquid Crystal Display Pixels with Field-Off Memory”, Adv. Mater., 2025. (Drafting)
- J.Y. Choi, J.S. Ma, W.S. Kim*, “Tunable High-Selectivity Wideband Bandpass Filter Using Triple-Mode Stub-Loaded Resonators Based on Liquid Crystals”, IEEE Access, 2025 (Submitted).
- A. Pradeep, Y. Montelongo, J.S. Ma, Z. Xu, T. Wang, J. Qin, C. Nourshagh, S. J. Elston, and S. M. Morris, “From Millimeters to Microns: A Hybrid Strategy for Reconfigurable Liquid-Crystal Patterning”, Small Methods., 2025 (Submitted).
- B. Mee et al., “Reconfigurable Optically-Transparent Antenna Using Drop-on-Demand Printed Nematic Liquid Crystals”, Adv. Eng. Mater., 2025 (Submitted).
- J. Ma, W. Kamal, A. Pradeep, A. J. Orr, S.-W. Oh, J.-Y. Choi, J. Guo, B. Mee, H.-W. Oh, J.-H. Lee, A. A. Castrejon-Pita*, S. J. Elston*, W.-S. Kim*, and S. M. Morris*, “Advanced image-integrated smart windows using printed electrochromic polymer-dispersed liquid crystal droplets,” Adv. Opt. Mater., 2025. (Link)
- J. Ma, A. Pradeep, S.W. Oh, J.H. Lee, J.Y. Choi, S.O. Cha, H.W. Oh, W.S. Kim*, “Operating temperature control in push-pull azobenzene-doped liquid crystal light-driven devices via a UV absorber”, Dyes and Pigments, 2025. (Link)
- S.-H. Lee+, S.-G. Park+, J. Ma, W.-S. Kim, and S.-W. Oh*, “High-performance switchable visor for augmented reality using low-voltage, fast-response cholesteric liquid crystals,” Dyes and Pigments, 2025. (Link)
- S.-O. Cha, J.-H. Ka, I.-B. Kong, J. Ma, S.-Y. Park, and W.-S. Kim*, “Off-Center Rotational Dynamics in Virtual Reality: Effects on Cybersickness and Presence,” IEEE Access, 2025. (Link)
- A. Pradeep*, U. Mur, J. Ma, N. Spiller, Y. Jin, W. Kamal, S. J. Elston*, and S. M. Morris*, “Locking metastable topological domains in nematic liquid crystal Pi cells,” Adv. Funct. Mater., 2025. (Editor’s Choice) (Link)
- J.-Y. Choi, J. Ma, and W.-S. Kim*, “Reconfigurable wideband bandpass filter using stepped impedance resonator based on liquid crystals,” Electronics, 2025. (Link)
- S. Park, J. Ma, S. Oh, and W. Kim, “Blur image representation in defocus using generalized Gaussian kernel,” Inf. Disp., 2025. (Link)
- J.-Y. Choi, J. Ma, H. Oh, and W.-S. Kim*, “Reconfigurable narrow-band bandpass filter using electrically-coupled open-loop resonators based on liquid crystals,” J. Phys. D: Appl. Phys., 2024. (Link)
- J.-H. Lee, J. Ma, C.-H. An, G.-H. Lee, and S.-W. Oh*, “Advanced light: Liquid crystals-based ultra-broadband polarization rotator for functional smart devices,” Small Methods, 2023. (Link)
- J. Ma, J.-Y. Choi, S. Park, I. Kong, D. Kim, C. Lee, Y. Youn, M. Hwang, S.-W. Oh*, W. Hong*, and W.-S. Kim*, “Liquid crystals for advanced smart devices with microwave and millimeter-wave applications: Recent progress for next-generation communication,” Adv. Mater., 2023. (Frontispiece Cover) (Link)
- H. Shin+, J. Ma+, J.-Y. Choi+, and W.-S. Kim*, “Phase shifting enhancement of a substrate-integrated waveguide phase shifter based on liquid crystal,” Appl. Sci., 2023. (+ equal contribution) (Link)
- J. Ma, J.-Y. Choi, H. Shin, J. Lee, S.-W. Oh*, and W.-S. Kim*, “An evaluation of surface-active agent hexadecyltrimethylammonium bromide with vertical self-alignment properties to align liquid crystals for various cell gap conditions,” Appl. Sci., 2022. (Link)
- J. Ma, J.-Y. Choi, S.-W. Oh, and W.-S. Kim, “Liquid-crystal-based floating-electrode-free coplanar waveguide phase shifter with an additional liquid-crystal layer for 28-GHz applications,” J. Phys. D: Appl. Phys., 2021. (Link)
- J. Ma, J.-Y. Choi, and W.-S. Kim, “액정의 고주파 대역 특성과 RF 응용 기술 동향,” Information Display, 22(3), 2021. (Link)
International Conference Presentations
- H. Oh, S. Park, J.-Y. Choi, J. Ma, S. Choi, and W.-S. Kim, “Analysis of Meander Delay Line Liquid Crystal Phase Shifter using Director Angle Extraction,” IMID, 2024.
- J.-Y. Choi, J. Ma, H. Oh, and W.-S. Kim, “Characterization of Nematic Liquid Crystals at 10 GHz using an Open Stub Resonator,” AP-S/URSI, 2024. (Link)
- J.-Y. Choi, J. Ma, H. Shin, and W.-S. Kim, “Reconfigurable Phased Array Antenna Based on Liquid Crystal with Miniaturized Bandpass Filter,” ISAP, Oct. 31–Nov. 3, 2022. (Link)
- H. Shin, J.-Y. Choi, J. Ma, and W.-S. Kim, “Phase Shift Enhancement of Substrate Integrated Waveguide Phase Shifter Using Liquid Crystal,” IMID, Korea, Aug. 23–26, 2022. (Link)
- J. Ma, J.-Y. Choi, H. Shin, and W.-S. Kim, “Comparative Analysis of Liquid-Crystal Driving between the Grounded-Coplanar Waveguide and the Floating-Electrode-Free Coplanar Waveguide in Liquid-Crystal Phase Shifters,” AP-S/URSI, 2022. (Link)
- J. Ma, H. Shin, and W.-S. Kim, “Analysis about Novel Design of Liquid Crystal Based Floating Electrode Free Coplanar Waveguide Phase Shifter for Performance Improvement,” IMID, Korea, Aug. 25–27, 2021.
- S. Cha, J. Ma, and W.-S. Kim, “Concept and Numerical Modeling for Virtual Acceleration Sense on Vestibular Organ using Focused Ultrasound,” IMID, Korea, Aug. 25–28, 2020.
Domestic Conference Presentations
- J. Ma, S.-W. Oh, J.-Y. Choi, H. Oh, S. M. Morris*, and W.-S. Kim*, “Enhancing Light-driven Polymer Stabilized Liquid Crystal Smart Devices,” BLCS, 2024. (BLCS)
- J.-Y. Choi, J. Ma, H. Oh, and W.-S. Kim*, “Characterization of Nematic Liquid Crystal at 10 GHz using Director Angle Extraction,” Korea Liquid Crystal Conference, 2024.
- J.-Y. Choi, J. Ma, S. Park, and W.-S. Kim*, “전기적 커플링 오픈 스터브를 이용한 소형 액정 기반 가변 광대역 대역저지 필터,” IEIE Summer Conference, 2023.
Academic Service — Journal Reviewer
- Engineering Research Express (IOP) — 2023 – Current · Reviews: 2
- Journal of Physics D: Applied Physics (IOP) — 2025 – Current · Reviews: 1
- Liquid Crystals (Taylor & Francis) — 2025 – Current · Reviews: 1
Scholarships, Honors & Awards
- Jang Young-Sil Postdoctoral Fellowship, KAIST 2025
- POSTECHIAN Fellowship, POSTECH 2024
- Excellence Awards (2nd Prize), EE Dept. Outstanding Performance Contest, POSTECH 2024
- Excellent Paper Challenge Prize, POSTECH Best Paper Competition 2024
- Samsung Electronics MX Division Sponsorship (Antenna Prior Research Organization) 2023
- Grand Prize, The 8th Electromagnetic Wave Measurement Thesis Contest (KIEES) 2023
- BK21 FOUR Outstanding Graduate Student International Funding (Oxford) 2023
- BK21 Interdisciplinary Research Group Support Funding 2023
- Kim Jong-Han Foundation Scholarship 2018 – 2019