Han-Joon Kim

Dr. Han-Joon Kim


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

View All Publications
23 January 2020 in Nature Communications
Verified
Journal Article
Open access
PDF file
RLRongzhou Lin
Rongzhou Lin
HKHan-Joon Kim
Han-Joon Kim
SASippanat Achavananthadith
Sippanat Achavananthadith
SKSelman A. Kurt
Selman A. Kurt
STShawn C. C. Tan
Shawn C. C. Tan
JHJohn S. Ho
John S. Ho
Networks of sensors placed on the skin can provide continuous measurement of human physiological signals for applications in clinical diagnostics, athletics and human-machine interfaces. Wireless and battery-free sensors are particularly desirable for reliable long-term monitoring, but current approaches for achieving this mode of operation rely on near-field technologies that require close proximity (at most a few centimetres) between each sensor and a wireless readout device. Here, we report near-field-enabled clothing capable of establishing wireless power and data connectivity between multiple distant points around the body to create a network of battery-free sensors interconnected by proximity to functional textile patterns. Using computer-controlled embroidery of conductive threads, we integrate clothing with near-field-responsive patterns that are completely fabric-based and free of fragile silicon components. We demonstrate the utility of the networked system for real-time, multi-node measurement of spinal posture as well as continuous sensing of temperature and gait during exercise.

21 April 2022 in Nature Communications
Verified
Journal Article
Open access
PDF file
RLRongzhou Lin
Rongzhou Lin
HKHan-Joon Kim
Han-Joon Kim
SASippanat Achavananthadith
Sippanat Achavananthadith
Ze XiongZe Xiong
Ze Xiong
JLJason Lee
Jason Lee
JHJohn S. Ho
John S. Ho
Electronic textiles capable of sensing, powering, and communication can be used to non-intrusively monitor human health during daily life. However, achieving these functionalities with clothing is challenging because of limitations in the electronic performance, flexibility and robustness of the underlying materials, which must endure repeated mechanical, thermal and chemical stresses during daily use. Here, we demonstrate electronic textile systems with functionalities in near-field powering and communication created by digital embroidery of liquid metal fibers. Owing to the unique electrical and mechanical properties of the liquid metal fibers, these electronic textiles can conform to body surfaces and establish robust wireless connectivity with nearby wearable or implantable devices, even during strenuous exercise. By transferring optimized electromagnetic patterns onto clothing in this way, we demonstrate a washable electronic shirt that can be wirelessly powered by a smartphone and continuously monitor axillary temperature without interfering with daily activities.

27 September 2017 in IEEE Access
Verified
Journal Article
Open access
HKHan-Joon Kim
Han-Joon Kim
HHHiroshi Hirayama
Hiroshi Hirayama
SKSanghoek Kim
Sanghoek Kim
KHKi Jin Han
Ki Jin Han
RZRui Zhang
Rui Zhang
JCJi-Woong Choi
Ji-Woong Choi
Near-field magnetic wireless systems have distinct advantages over their conventional far-field counterparts in water-rich environments, such as underwater, underground, and in biological tissues, due to lower power absorption. This paper presents a comprehensive review of near-field magnetic wireless power transfer (WPT) and communication technologies in a variety of applications from general free-space systems, to implantable biomedical devices we find of particular interest. To implement a fully wirelessly-powered implantable system, both high-efficiency power transfer and high-rate data communication are essential. This paper first presents the history and the fundamentals of near-field WPT and communication in free-space systems, followed by technical details for their specific use in implantable biomedical devices. Finally, this paper reviews recent advances in simultaneous wireless information and power transfer (SWIPT) and highlights their applications in implantable biomedical systems. The knowledge reviewed in the paper could provide intuition in the design of various wireless and mobile systems such as wireless body area networks, small-cell 5G cellular, as well as in-body biomedical applications, especially for efficient power and data management and higher security.

8 March 2016 in IEEE Transactions on Antennas and Propagation
Verified
Journal Article
Closed access
HKHan-Joon Kim
Han-Joon Kim
JPJinho Park
Jinho Park
KOKyoung-Sub Oh
Kyoung-Sub Oh
JCJihwan P. Choi
Jihwan P. Choi
JJJae Eun Jang
Jae Eun Jang
JCJi-Woong Choi
Ji-Woong Choi
In this paper, we propose a novel method realizing multi-input-multi-output (MIMO) transmission in near-field magnetic induction (NFMI) communication for increasing channel capacity where limited capacity is a major bottleneck problem in magnetic communication systems. Since conventional magnetic communication systems using the same antenna patterns cannot easily implement MIMO transmission due to strong crosstalk between transmitters, we propose heterogeneous antenna arrays with multipole antennas, enabling crosstalk cancellation. We confirm the crosstalk cancellation of the proposed antenna array through numerical simulations and experiments, and verify the capacity enhancement of the proposed NFMI communication system over conventional NFMI communication schemes.

3 December 2024 in Nature Communications
Verified
Journal Article
Open access
PDF file
XFXuemei Fu
Xuemei Fu
GWGuanxiang Wan
Guanxiang Wan
HGHongchen Guo
Hongchen Guo
HKHan-Joon Kim
Han-Joon Kim
ZYZijie Yang
Zijie Yang
BTBenjamin C. K. Tee
Benjamin C. K. Tee
Alternating-current electroluminescent fibres are promising candidates as light sources for smart textiles and soft machines. However, physical damage from daily use causes device deterioration or failure, making self-healable electroluminescent fibres attractive. In addition, soft robots could benefit from light-emitting combined with magnetically actuated functions. Here, we present a self-healing and actuatable Scalable Hydrogel-clad Ionotronic Nickel-core Electroluminescent (SHINE) fibre which achieves a record luminance of 1068 cd × m−2 at 5.7 V × μm−1. The SHINE fibre can self-heal across all constituent layers after being severed, recovering 98.6% of pristine luminance and maintaining for over 10 months. SHINE fibre is also magnetically actuatable due to the ferromagnetic nickel electrode core, enabling a soft robotic fibre with omnidirectional actuation and electro-luminescence. Our approach to this multifunctional fibre broadens the design of fibre electronics and fibre robots, with applications in interactive displays and damage-resilient navigation.

1 May 2017
Verified
Conference Paper
Closed access
KKKyungtae Kim
Kyungtae Kim
HKHan-Joon Kim
Han-Joon Kim
JCJi-Woong Choi
Ji-Woong Choi
While many companies have provided wireless charging technologies to users recently, a charging distance is very short due to a drastic drop of magnetic fields. A lot of researches have been carried out steadily to increase the wireless charging distance. Magnetic beamforming is one of promising technologies to achieve this vision. However, conventional magnetic beamforming schemes require complex calculations to enhance the power transfer efficiency. This paper presents an enhanced magnetic beamforming scheme by adopting a non-coupling coil pattern as the transfer coil arrays which can obtain higher power transfer efficiency at longer distance with lower computation complexity. We provide concept of a coupling cancellation with the proposed coil pattern, and verify the enhanced performance via circuit simulations in terms of the power transfer efficiency compared the conventional magnetic beamforming schemes which have the magnetic couplings between the transfer coils. The proposed scheme can play an important role in the future IoT world which is composed of many multiple electronic devices and wireless sensors.