Bio

Youngbin Tchoe

#110-801-13, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Korea | +82-052-217-2756 | ybtchoe@unist.ac.kr

EDUCATION AND EXPERIENCE

Department of Biomedical Engineering

Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea

Assistant Professor 2023 – 

Integrated Electronics and Biointerface Laboratory

UC San Diego, La Jolla, CA, USA

Assistant Project Scientist 2023

Postdoctoral Researcher 2018 – 2023

* Advisor: Prof. Shadi A. Dayeh

Novel neural interface development for human brain recording

• World first demonstration of multi-thousands channel human brain recording

• Displaying cortical activities directly on cortical surface with micro-LED array

• in vivo and in vitro intracellular recording nanowire array development

Quantum Nanomaterials and Nanodevices Laboratory

Seoul National University, Seoul, Korea

Postdoctoral Researcher 2018

Ph.D. in Physics 2011 – 2018

* Advisor: Prof. Gyu-Chul Yi

1D+2D hybrid nanomaterials based nanodevice development

• High-density integration of bottom-up grown 1D semiconductor nanostructures using semiconductor nanorods grown on graphene films

Advanced nanostructured LED development

• Nanostructured GaN LEDs fabrication for multicolor (GaN microdonut) and high-power light emitters (Metal-cored GaN microtube)

• Led collaborative nanostructured LED projects with Samsung Electronics and head-up-display project with Hyundai Motors

MBE of III-V semiconductor nanostructures on 2D materials

• Refurbished III-V MBE and optimized growth conditions for nanomaterials on 2D materials

• Developed ZnO/graphene/InAs system for UV and mid-IR dual-wavelength photodetector

Manybody Physics Group

Sungkyunkwan University, Suwon, Korea

Undergraduate Research Assistant 2010 – 2012

* Advisor: Prof. Jung Hoon Han

• Condensed matter physics (esp. Skyrmion) dynamic simulator development (C++, Windows API)

Seoul National University, Seoul, Korea
B.S. in Physics 2006 – 2011

RESEARCH TOPICS

• Brain wave visualization with flexible micro-ECoG/micro-LED array 2020 – 2023

• Multi-thousands channel intraoperative human brain recording 2018 – 2022

• Nanowire electrodes for in vitro and in vivo intracellular recordings 2018 – 2023

• Ultrathin, individually addressable nanorod device arrays on graphene 2016 – 2018

• Ultrathin and flexible micro-LED arrays using GaN microdisks on graphene 2017 – 2018

• GaN nano- and micro-structure LED fabrication 2011 – 2018

• Molecular beam epitaxy of III-As semiconductor nanorod heterostructures on graphene 2013 – 2018

• Computational study of Skyrmion dynamics 2010 – 2012

AWARDS AND FELLOWSHIPS

• Individual Research in Basic Science and Engineering (Postdoc fellowship), National Research Foundation of Korea (NRF) 2019 – 2020

• Best Ph.D. Thesis Award in Physics, College of Natural Science, Seoul National University 2018

• Science Fellowship in Physics (Ph.D. student), POSCO TJ Park Foundation 2014 – 2016

• Excellent presentation award, Applied Physics, Korean Physical Society 2016

• Brain Korea 21+ Scholarship, Seoul National University 2014, 2015

• Superior Academic Performance, Seoul National University 2011, 2012

• The National Scholarship for Science and Engineering 2006, 2007

PUBLICATIONS

31. “Constructing 2D maps of human spinal cord activity and isolating the functional midline with high-density microelectrode arrays."
Samantha M. Russman, Daniel R. Cleary, Youngbin Tchoe, Andrew M. Bourhis, Brittany Stedelin, Joel Martin, Erik C. Brown, Xinlian Zhang, Aaron Kawamoto, Won Hyung A Ryu, Ahmed M Raslan, Joseph D Ciacci, Shadi A Dayeh
Science Translational Medicine 14(664) eabq4744 (2022)

30. “Human Brain Mapping with Multi-Thousand Channel PtNRGrids Resolves Novel Spatiotemporal Dynamics”
Youngbin Tchoe†, Andrew M Bourhis†, Daniel R Cleary†, Brittany Stedelin, Jihwan Lee, Karen J Tonsfeldt, Erik C Brown, Dominic Siler, Angelique C Paulk, Jimmy C Yang, Hongseok Oh, Yun Goo Ro, Keundong Lee, Samantha Russman, Mehran Ganji, Ian Galton, Sharona Ben-Haim, Ahmed M Raslan, Shadi A Dayeh
Science Translational Medicine 14 (628), eabj1441 (2022)

29. “Ultra-Sharp Nanowire Arrays Natively Permeate, Record, and Stimulate Intracellular Activity in Neuronal and Cardiac Networks”
Ren Liu†, Jihwan Lee†, Youngbin Tchoe†, Andrew Boris, Sang Heon Lee, Deborah Pre, Gaelle Robin, Mary Elizabeth Phipps, Jennifer S. Martinez, Anne Bang, Shadi A. Dayeh
Advanced Functional Materials, 2108378 (2022)

28. “Scalable Thousand Channel Penetrating Microneedle Arrays on Flex for Multimodal and Large Area Coverage Brain-Machine Interfaces”
Sang Heon Lee, Martin Thunemann, Keundong Lee, Daniel R. Cleary, Karen Tonsfeldt, Hongseok Oh, Farid Azzazy, Youngbin Tchoe, Andrew Bourhis, Lorraine Hossain, Yun Goo Ro, Atusnori Tanaka, Kıvılcım Kiliç, Anna Devor, and Shadi A. Dayeh
Advanced Functional Materials, 2112045 (2022)

27. “An individually addressable and flexible pressure sensor matrix by ZnO nanotube arrays on graphene"
Jun Beom Park, Ramesh Ghosh, Minho Song, Yunjae Hwang, Youngbin Tchoe, Rajendra Kumar Saroj, Asad Ali, Puspendu Guha, Bosung Kim, Sang-Woo Kim, Miyoung Kim, Gyu-Chul Yi
NPG Asia Materials 14(1), 1-13 (2022)

26. “Considerations and Recent Advances in Nanoscale Interfaces with Neuronal and Cardiac Networks”
Youngbin Tchoe, Jihwan Lee, Ren Liu, Andrew M. Bourhis, Ritwik Vatsyayan, Shadi Dayeh
Applied Physics Review 8(4), 041317 (2021)

25. “Dimension-and position-controlled growth of GaN microstructure arrays on graphene films for flexible device applications”
Dongha Yoo, Keundong Lee, Youngbin Tchoe, Puspendu Guha, Asad Ali, Rajendra K Saroj, Seokje Lee, ABM Islam, Miyoung Kim, Gyu-Chul Yi
Scientific Reports 11(1), 1–7 (2021)

24. “Fabrication of piezoresistive Si nanorod-based pressure sensor arrays: A promising candidate for portable breath monitoring devices”
Ramesh Ghosh, Minho S Song, JunBeom Park, Youngbin Tchoe, Puspendu Guha, Wanhee Lee, Yoonseo Lim, Bosung Kim, Sang-Woo Kim, Miyoung Kim, Gyu-Chul Yi
Nano Energy 80, 105537 (2021)

23. “Highly Sensitive and Flexible Pressure Sensors Using Position- and Dimension-Controlled ZnO Nanotube Arrays Grown on Graphene Film”
Jun Beom Park, Minho Song, Ramesh Ghosh, Rajendra Kumar Saroj, Yunjae Hwang, Youngbin Tchoe, Hongseok Oh, Hyeonjun Baek, Yoonseo Lim, Bosung Kim, Sang-Woo Kim, Gyu-Chul Yi
NPG Asia Materials 13(1), 1–9 (2021)

22. “Vertical monolithic integration of wide-and narrow-bandgap semiconductor nanostructures on graphene films”
Youngbin Tchoe, Janghyun Jo, HoSung Kim, Heehun Kim, Hyeonjun Baek, Keundong Lee, Dongha Yoo, Won Jun Choi, Miyoung Kim, Gyu-Chul Yi
NPG Asia Materials 13(1), 1–7 (2021)

21. “Microscale Physiological Events on the Human Cortical Surface”
Angelique C Paulk, Jimmy C Yang, Daniel R Cleary, Daniel J Soper, Milan Halgren, Alexandra R O'Donnell, Sang Heon Lee, Mehran Ganji, Yun Goo Ro, Hongseok Oh, Lorraine Hossain, Jihwan Lee, Youngbin Tchoe, Nicholas Rogers, Kivilcim Kiliç, Sang Baek Ryu, Seung Woo Lee, John Hermiz, Vikash Gilja, István Ulbert, Daniel Fabó, Thomas Thesen, Werner K Doyle, Orrin Devinsky, Joseph R Madsen, Donald L Schomer, Emad N Eskandar, Jong Woo Lee, Douglas Maus, Anna Devor, Shelley I Fried, Pamela S Jones, Brian V Nahed, Sharona Ben-Haim, Sarah K Bick, Robert Mark Richardson, Ahmed M Raslan, Dominic A Siler, Daniel P Cahill, Ziv M Williams, G Rees Cosgrove, Shadi A Dayeh, Sydney S Cash
Cerebral Cortex 31(8), 3678–3700 (2021)

20. “Individually addressable, high-density vertical nanotube Schottky diode crossbar array”
Youngbin Tchoe, Minho S Song, Heehun Kim, Hyeonjun Baek, Joon Young Park, Hongseok Oh, Keundong Lee, Kyungmin Chung, Jerome K Hyun, Gyu-Chul Yi
Nano Energy 76, 104955 (2020)

19. “Scaling study of molecular beam epitaxy grown InAs/Al2O3 films using atomic force microscopy”
Arpana Agrawal, Youngbin Tchoe
Thin Solid Films 709, 138204 (2020)

18. “Selective Formation of Porous Pt Nanorods for Highly Electrochemically Efficient Neural Electrode Interfaces”
M. Ganji, A. C. Paulk, J. C. Yang, N. W. Vahidi, S. H. Lee, R. Liu, L. Hossain, E. M. Arneodo, M. Thunemann, M. Shigyo, A. Tanaka, S. B. Ryu, S. W. Lee, Y. Tchoe, M. Marsala, A. Devor, D. R. Cleary, J. R. Martin, H. Oh, V. Gilja, T. Q. Gentner, S. I. Fried, E. Halgren, S. S. Cash, S. A. Dayeh
Nano Letters 19(9), 6244-6254 (2019)

17. “GaN microstructure light-emitting diodes directly fabricated on tungsten-metal electrodes using a micro-patterned graphene interlayer”
Kunook Chung, Keundong Lee, Youngbin Tchoe, Hongseok Oh, JunBeom Park, Jerome K Hyun, Gyu-Chul Yi
Nano Energy 60, 82-86 (2019)

16. “Free-standing and ultrathin inorganic light-emitting diode array”
Youngbin Tchoe, Kunook Chung, Keundong Lee, Janghyun Jo, Kyungmin Chung, Jerome K. Hyun, Miyoung Kim, Gyu-Chul Yi
NPG Asia Materials 11 (1), 37 (2019)

15. "Real-Time Characterization Using in situ RHEED Transmission Mode and TEM for Investigation of the Growth Behaviour of Nanomaterials”
Janghyun Jo, Youngbin Tchoe, Gyu-Chul Yi, and Miyoung Kim
Scientific Reports 8, 1694 (2018)

14. “Vertical ZnO Nanotube Transistor on a Graphene Film for Flexible Inorganic Electronics”
Hongseok Oh, JunBeom Park, Woojin Choi, Heehun Kim, Youngbin Tchoe, Arpana Agrawal, Gyu‐Chul Yi
Small 14(17), 1800240 (2018)

13. “Qualitative analysis of growth mechanism of polycrystalline InAs thin films grown by molecular beam epitaxy”
Arpana Agrawal, Youngbin Tchoe, Heehun Kim, Joon Young Park
Applied Surface Science 462(31), 81-85 (2018)

12. “ZnO nanotube waveguide arrays on graphene films for local optical excitation on biological cells”
Hyeonjun Baek, Hankyul Kwak, Minho S Song, Go Eun Ha, Jongwoo Park, Youngbin Tchoe, Jerome K Hyun, Hye Yoon Park, Eunji Cheong, Gyu-Chul Yi
APL Materials 5(4) 046106 2017 (2017)

11. “Flexible resistive random access memory using NiOx/GaN microdisk arrays fabricated on graphene films”
Keundong Lee, Jong-woo Park, Youngbin Tchoe, Jiyoung Yoon, Kunook Chung, Hosang Yoon, Sangik Lee, Chansoo Yoon, Bae Park, Gyu-Chul Yi
Nanotechnology 28(20) 206202 (2017)

10. “Microtube Light-Emitting Diode Arrays with Metal Cores”
Youngbin Tchoe, Chul-Ho Lee, Jun Beom Park, Hyeonjun Baek, Kunook Chung, Janghyun Jo, Miyoung Kim, and Gyu-Chul Yi
ACS Nano 10 (3), 3114–3120 (2016)

9. “Flexible GaN Light-Emitting Diodes Using GaN Microdisks Epitaxial Laterally Overgrown on Graphene Dots"
Kunook Chung, Hyobin Yoo, Jerome K. Hyun, Hongseok Oh, Youngbin Tchoe, Keundong Lee, Hyeonjun Baek, Miyoung Kim, Gyu-Chul Yi
Advanced Materials 28 (35), 7688-7694 (2016)

8. “Real-time device-scale imaging of conducting filament dynamics in resistive switching materials”
Keundong Lee, Youngbin Tchoe, Hosang Yoon, Hyeonjun Baek, Kunook Chung, Sangik Lee, Chansoo Yoon, Bae Ho Park, Gyu-Chul Yi
Scientific Reports 6, 27451 (2016)

7. “Centimeter-sized epitaxial h-BN films”
Hongseok Oh, Janghyun Jo, Youngbin Tchoe, Hosang Yoon, Hyun Hwi Lee, Sung-Soo Kim, Miyoung Kim, Byeong-Hyeok Sohn, Gyu-Chul Yi
NPG Asia Materials 8 (11), e330 (2016)

6. “Catalyst-free growth of InAs/InxGa1−xAs coaxial nanorod heterostructures on graphene layers using molecular beam epitaxy”
Youngbin Tchoe, Janghyun Jo, Miyoung Kim, and Gyu-Chul Yi
NPG Asia Materials 7, e206 (2015)

5. “Growth and optical characteristics of high-quality ZnO thin films on graphene layers”
Suk In Park, Youngbin Tchoe, Hyeonjun Baek, Jaehyuk Heo, Jerome K Hyun, Janghyun Jo, Miyoung Kim, Nam-Jung Kim, Gyu-Chul Yi
APL Materials 3 (1), 016103 (2015)

4. “Statistical Analysis of Electrical Properties of Octanemonothiol versus Octanedithol in PEDOT: PSS-Electrode Molecular Junctions”
Hanki Lee, Hyunhak Jeong, Dongu Kim, Wang-Taek Hwang, Youngbin Tchoe, Gyu-Chul Yi, Takhee Lee
Journal of Nanoscience and Nanotechnology 15 (8), 5937-3941 (2015)

3. “Growth and characterizations of GaN micro-rods on graphene films for flexible light emitting diodes”
Kunook Chung, Hyeonjun Beak, Youngbin Tchoe, Hongseok Oh, Hyobin Yoo, Miyoung Kim, Gyu-Chul Yi
APL Materials 2 (9), 092512 (2014)

2. “Variable-Color Light-Emitting Diodes Using GaN Microdonut arrays”
Youngbin Tchoe, Janghyun Jo, Miyoung Kim, Jae;hyuk Heo, Geonwook Yoo, Cheolsoo Sone, and Gyu-Chul Yi
Advanced Materials 26 (19), 3009-3023 (2014)

1. “Skyrmion generation by current”
Youngbin Tchoe and Jung Hoon Han
Physical Review B 85, 174416 (2012)

PATENTS

1. “Multi-hundred or thousand channel electrode electrophysiological array and fabrication method”
Shadi A. Dayeh, Youngbin Tchoe, Andrew M. Bourhis
WO2022192560A1(PCT)                                                                                              2022

2. “Microelectrode Grid with Flap for Continuous Intraoperative Neuromonitoring”
Shadi Dayeh, Youngbin Tchoe, Ahmed Raslan
US Patent App. 63/306,545                                                                                           2022

2. “Sharp, vertically aligned nanowire electrode arrays, high-yield fabrication and intracellular recording”
Shadi Dayeh, Ren Liu, Youngbin Tchoe
WO2019217553A2 (PCT)                                                                                         2021
US20210093246A1                                                                                                   2022

3. “Light Emitting Diode and Method for Preparing the Same”
Jinho Hwang, Daeik Jung, Gunsoo Jin, Youngbin Tchoe, Keundong Lee,
Gyu-Chul Yi, Korean Patent 10-1807021                                                                 2017

4. “Apparatus for Providing Tactile Information”
Gyu-Chul Yi, Jun Beom Park, Youngbin Tchoe
Korean Patent 10-1790614                                                                                 2017

5. “Nano Structure Semiconductor Light Emitting Devices”
Geon Wook Yoo, Gyu-Chul Yi, Youngbin Tchoe, Jae Hyuk Heo
Korean Patent 10-2014-0074785                                                                                    2014

 LAB EXPERTISE
Microfabrication of Neural Interface Devices

• Highly experienced with the fabrication of biocompatible, human grade ultrathin and ultra-flexible neural interface device fabrication

Semiconductor Device Processing

• Highly experienced with nano- and micro-structure LED device fabrication

• Highly-skilled in ultrathin and freestanding semiconductor device processing

in-vivo brain recording

• Experienced in human brain recording in neurosurgery operating room (OHSU and UCSD hospitals)
• Experienced in rodent brain recordings, especially the whisker barrel cortex

in-vitro cell culture & recording

• Experienced in setting up a cell culture room and cultured cardiomyocyte cells
• Nanowire electrode recording from cultured neurons and cardiomyocytes

Electrochemistry & Electrophysiology

• Electrochemical impedance spectroscopy using gamry systems

• Extracellular electrophysiological recording from brain

Material Growth

• Highly experienced with operation and maintenance of MBE

• Catalyst-free semiconductor nanostructures growth on graphene using MBE

Characterizations

• Highly experienced with EL setup, maintenance, and characterizations

• Highly experienced with SEM system maintenance

• RHEED installation, maintenance, characterization, and analysis

• TEM, STEM structural characterizations

Computational Skills

• MATLAB neural signal analysis. High gamma functional localization, propagating beta wave analysis,
  current source density analysis.

• Developed dynamic spintronics simulator using C/C++ (Monte Carlo Simulation, Runge-Kutta fourth order method) & Windows API for visualization (Phys. Rev. B 2012)

• Current spreading simulation in GaN nanostructure LEDs using COMSOL Multiphysics 4.3b semiconductor module (ACS Nano 2016)

• InxGa1‒xN/GaN quantum well blue shift & emission color estimation using C/C++ (Adv. Mater. 2014)

PROFESSIONAL ACTIVITIES

• Member of Society for Neuroscience (SfN)

• Member of Materials Research Society (MRS)

• Member of Optical Society of America (OSA)

• Member of American Ceramic Society (ACerS)

• Member of Korean Vacuum Society (KVS)

• Member of Optical Society of Korea (OSK)

TEACHING EXPERIENCE

Ulsan National Institute of Science and Technology

• Advanced Engineering Mathematics (BME21001)                                     2023

Teaching Assistant, Department of Physics and Astronomy, Seoul National University

• Physics 001 (Mechanics and Electromagnetism for Engineers)                                     2012

• Computational Physics                                                                                         2012

• Physics 1 (Mechanics and Electromagnetism for Engineers)                                     2013

• Computational Physics                                                                                         2013

• Research & Education Program                                                                            2017