Sehui Chang

Ms. Sehui Chang


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 May 2024 in Science Robotics
Verified
Journal Article
Closed access
JPJinhong Park
Jinhong Park
MKMinseok Kim
Minseok Kim
JKJoonsoo Kim
Joonsoo Kim
SCSehui Chang
Sehui Chang
MLMincheol Lee
Mincheol Lee
DKDae-Hyeong Kim
Dae-Hyeong Kim
Avian eyes have deep central foveae as a result of extensive evolution. Deep foveae efficiently refract incident light, creating a magnified image of the target object and making it easier to track object motion. These features are essential for detecting and tracking remote objects in dynamic environments. Furthermore, avian eyes respond to a wide spectrum of light, including visible and ultraviolet light, allowing them to efficiently distinguish the target object from complex backgrounds. Despite notable advances in artificial vision systems that mimic animal vision, the exceptional object detection and targeting capabilities of avian eyes via foveated and multispectral imaging remain underexplored. Here, we present an artificial vision system that capitalizes on these aspects of avian vision. We introduce an artificial fovea and vertically stacked perovskite photodetector arrays whose designs were optimized by theoretical simulations for the demonstration of foveated and multispectral imaging. The artificial vision system successfully identifies colored and mixed-color objects and detects remote objects through foveated imaging. The potential for use in uncrewed aerial vehicles that need to detect, track, and recognize distant targets in dynamic environments is also discussed. Our avian eye–inspired perovskite artificial vision system marks a notable advance in bioinspired artificial visions.

22 February 2023 in Science Robotics
Verified
Journal Article
Closed access
MKMinsung Kim
Minsung Kim
SCSehui Chang
Sehui Chang
MKMinsu Kim
Minsu Kim
JYJi-Eun Yeo
Ji-Eun Yeo
MKMinseok Kim
Minseok Kim
Young Min SongYoung Min Song
Young Min Song
With the rise of mobile robotics, including self-driving automobiles and drones, developing artificial vision for high-contrast and high-acuity imaging in vertically uneven illumination conditions has become an important goal. In such situations, balancing uneven illumination, improving image contrast for facile object detection, and achieving high visual acuity in the main visual fields are key requirements. Meanwhile, in nature, cuttlefish (genus Sepia ) have evolved an eye optimized for vertically uneven illumination conditions, which consists of a W-shaped pupil, a single spherical lens, and a curved retina with a high-density photoreceptor arrangement and polarized light sensitivity. Here, inspired by the cuttlefish eye, we report an artificial vision system consisting of a W-shaped pupil, a single ball lens, a surface-integrated flexible polarizer, and a cylindrical silicon photodiode array with a locally densified pixel arrangement. The W-shaped pupil integrated on the ball lens balances vertically uneven illumination, and the cylindrical silicon photodiode array integrated with the flexible polarizer enables high-contrast and high-acuity imaging.

20 September 2024 in Science Advances
Verified
Journal Article
Open access
MKMin Su Kim
Min Su Kim
MKMinseok Kim
Minseok Kim
MLMincheol Lee
Mincheol Lee
HJHyuk Jae Jang
Hyuk Jae Jang
DKDo Hyeon Kim
Do Hyeon Kim
Young Min SongYoung Min Song
Young Min Song
Biologically inspired artificial vision research has led to innovative robotic vision systems with low optical aberration, wide field of view, and compact form factor. However, challenges persist in object detection and recognition against complex backgrounds and varied lighting. Inspired by the feline eye, which features a vertically elongated pupil and tapetum lucidum, this study introduces an artificial vision system designed for superior object detection and recognition in a monocular framework. Using a slit-like elliptical aperture and a patterned metal reflector beneath a hemispherical silicon photodiode array, the system reduces excessive light and enhances photosensitivity. This design achieves clear focus under bright light and enhanced sensitivity in dim conditions. Theoretical and experimental analyses demonstrate the system’s ability to filter redundant information and detect camouflaged objects in diverse lighting, representing a substantial advancement in monocular camera technology and the potential of biomimicry in optical innovations.

26 July 2020 in Micromachines
Verified
Journal Article
Open access
PDF file
SCSehui Chang
Sehui Chang
GLGil Ju Lee
Gil Ju Lee
Young Min SongYoung Min Song
Young Min Song
Over the past few decades, nanowires have arisen as a centerpiece in various fields of application from electronics to photonics, and, recently, even in bio-devices. Vertically aligned nanowires are a particularly decent example of commercially manufacturable nanostructures with regard to its packing fraction and matured fabrication techniques, which is promising for mass-production and low fabrication cost. Here, we track recent advances in vertically aligned nanowires focused in the area of photonics applications. Begin with the core optical properties in nanowires, this review mainly highlights the photonics applications such as light-emitting diodes, lasers, spectral filters, structural coloration and artificial retina using vertically aligned nanowires with the essential fabrication methods based on top-down and bottom-up approaches. Finally, the remaining challenges will be briefly discussed to provide future directions.

19 June 2024 in Carbon
Verified
Journal Article
Closed access
SPSnehal L. Patil
Snehal L. Patil
OPOmkar Y. Pawar
Omkar Y. Pawar
TDTukaram D. Dongale
Tukaram D. Dongale
SCSehui Chang
Sehui Chang
Sooman LimSooman Lim
Sooman Lim
Young Min SongYoung Min Song
Young Min Song