Bonghwan Kim

Dr. Bonghwan Kim

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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10 January 2022 in Coatings
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Journal Article
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AUAbu Sadat M. Iftekhar Uddin
Abu Sadat M. Iftekhar Uddin
DLDongin Lee
Dongin Lee
CCChanseob Cho
Chanseob Cho
BKBonghwan Kim
Bonghwan Kim
The current study investigated the fabrication of multi-walled carbon nanotubes (MWCNTs) adhering to Barium titanate (BaTiO3) nanoparticles and poly(vinylidene fluoride) (PVDF) nanocomposites, as well as the impact of MWCNT on the PVDF-BaTiO3 matrix in terms of dielectric constant and dielectric loss with a view to develop a high performance piezoelectric energy harvester in future. The capacity and potential of as-prepared nanocomposite films for the fabrication of high-performance flexible piezoelectric nanogenerator (PNG) were also investigated in this work. In particular, five distinct types of nanocomposites and films were synthesized: PB (bare PVDF–BaTiO3), PBC-1 (PVDF–BaTiO3-0.1 wt% CNT), PBC-2 (PVDF–BaTiO3-0.3 wt% CNT), PBC-3 (PVDF–BaTiO3-0.5 wt% CNT), and PBC-4 (PVDF–BaTiO3-1 wt% CNT). The dielectric constant and dielectric loss increased as MWCNT concentration increased. Sample PBC-3 had the optimum dielectric characteristics of all the as-prepared samples, with the maximum output voltage and current of 4.4 V and 0.66 μA, respectively, with an applied force of ~2N. Fine-tuning the BaTiO3 content and thickness of the PNGs is likely to increase the harvester’s performance even more. It is anticipated that the work would make it easier to fabricate high-performance piezoelectric films and would be a suitable choice for creating high-performance PNG.

6 April 2023 in Nanomaterials
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Journal Article
Open access
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JIJahirul Islam
Jahirul Islam
HLHyeji Lee
Hyeji Lee
KLKihak Lee
Kihak Lee
CCChanseob Cho
Chanseob Cho
BKBonghwan Kim
Bonghwan Kim
In this context, the open-circuit voltage generated by either poly (vinylidene fluoride) or PVDF and ZnO composite sample before being enhanced to 4.2 V compared to 1.2 V for the samples of pure PVDF. The spin coating method was used to create a composite film, which served as a piezoelectric nanogenerator (PNG). Zinc oxide (ZnO) nanoparticles and PVDF serve as the matrix for the coating structure. Thin films were created that employed the spin coating method to achieve the desired results of ZnO’s non-brittle outcome and piezoelectric characteristics, as well as PVDF for use in self-powered devices. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared (FT-IR) were used to evaluate the properties of these formations. The electrical properties of the film were measured using an oscilloscope. Results indicated that by adding ZnO nanoparticles to the PVDF samples, piezoelectric capabilities were enhanced compared to samples containing PVDF only. These results point to promising uses for various wearable devices, such as water strider robot systems and self-operating equipment.

1 September 2004 in Sensors and Actuators A: Physical
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Journal Article
Closed access
BKBonghwan Kim
Bonghwan Kim
SPSang-Jun Park
Sang-Jun Park
KCKukjin Chun
Kukjin Chun
Dongil ChoDongil Cho
Dongil Cho
WPWoong-Ki Park
Woong-Ki Park
SYSoo Yun
Soo Yun

6 August 2024 in Applied Sciences
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Journal Article
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JJJinwoo Jung
Jinwoo Jung
KLKihak Lee
Kihak Lee
BKBonghwan Kim
Bonghwan Kim
In this study, we thoroughly analyzed the linearity and repeatability of force-sensing resistor (FSR) sensors through static load tests to ensure their reliability. The novelty of this research lies in its comprehensive evaluation and direct comparison of two widely used FSR sensors, i.e., Flexiforce A201-1 and Interlink FSR-402, under various loading conditions by employing a robust calibration methodology. This study provides detailed insights into the sensors’ performances, offering practical calibration equations that enhance measurement precision and reliability, which have not been extensively documented in previous studies. Our results demonstrate that the linearity of thin film FSR sensors is highly accurate, closely resembling a straight line. We employed M1 Class weights, applying loads ranging from 20 g to 300 g. The resistance of the FSR sensors, which varies with the applied load, was measured using a voltage divider circuit and an analog-to-digital converter of a microcontroller. MATLAB was used to calculate the average output voltage for each applied load and fixed resistance. Additionally, we examined the relationships among load, FSR sensor resistance, and conductivity. Our research indicates that with precise calibration, thin film FSR sensors can be highly reliable for force measurement applications.

1 November 2017 in Applied Surface Science
Verified
Journal Article
Closed access
HKHwa-Min Kim
Hwa-Min Kim
CLChang Hyun Lee
Chang Hyun Lee
SSSun Young Shon
Sun Young Shon
BKBonghwan Kim
Bonghwan Kim

20 May 2014 in Physica Status Solidi (a)
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Journal Article
Closed access
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CCChanseob Cho
Chanseob Cho
DKDaeyoung Kong
Daeyoung Kong
JOJung-Hwa Oh
Jung-Hwa Oh
BKBonghwan Kim
Bonghwan Kim
BLByeungleul Lee
Byeungleul Lee
JLJonghyun Lee
Jonghyun Lee