5 results on '"Jiyong Yoon"'
Search Results
2. Stretchable colour-sensitive quantum dot nanocomposites for shape-tunable multiplexed phototransistor arrays
- Author
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Jun-Kyul Song, Junhee Kim, Jiyong Yoon, Ja Hoon Koo, Hyunjin Jung, Kyumin Kang, Sung-Hyuk Sunwoo, Seungwon Yoo, Hogeun Chang, Jinwoung Jo, Woonhyuk Baek, Sanghwa Lee, Mincheol Lee, Hye Jin Kim, Mikyung Shin, Young Jin Yoo, Young Min Song, Taeghwan Hyeon, Dae-Hyeong Kim, and Donghee Son
- Subjects
Excipients ,Polymers ,Quantum Dots ,Biomedical Engineering ,Color ,General Materials Science ,Bioengineering ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Nanocomposites - Abstract
High-performance photodetecting materials with intrinsic stretchability and colour sensitivity are key requirements for the development of shape-tunable phototransistor arrays. Another challenge is the proper compensation of optical aberrations and noises generated by mechanical deformation and fatigue accumulation in a shape-tunable phototransistor array. Here we report rational material design and device fabrication strategies for an intrinsically stretchable, multispectral and multiplexed 5 × 5 × 3 phototransistor array. Specifically, a unique spatial distribution of size-tuned quantum dots, blended in a semiconducting polymer within an elastomeric matrix, was formed owing to surface energy mismatch, leading to highly efficient charge transfer. Such intrinsically stretchable quantum-dot-based semiconducting nanocomposites enable the shape-tunable and colour-sensitive capabilities of the phototransistor array. We use a deep neural network algorithm for compensating optical aberrations and noises, which aids the precise detection of specific colour patterns (for example, red, green and blue patterns) both under its flat state and hemispherically curved state (radius of curvature of 18.4 mm).
- Published
- 2021
3. A Soft Pressure Sensor Array Based on a Conducting Nanomembrane
- Author
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Duhwan Seong, Jiyong Yoon, Hyoung Won Baac, Changhwan Shin, Mikyung Shin, Kyumin Kang, Soojung An, Daekwang Jung, Hyunjin Jung, Woo-Seok Kim, Dong Hee Son, and Sangmin Won
- Subjects
piezoresistive ,Materials science ,stretchable electronics ,business.industry ,Mechanical Engineering ,Stretchable electronics ,Electronic skin ,Linearity ,electronic skin ,Substrate (electronics) ,Piezoresistive effect ,Pressure sensor ,Article ,Strain energy ,Control and Systems Engineering ,TJ1-1570 ,Optoelectronics ,Sensitivity (control systems) ,pressure sensor ,Mechanical engineering and machinery ,Electrical and Electronic Engineering ,business - Abstract
Although skin-like pressure sensors exhibit high sensitivity with a high performance over a wide area, they have limitations owing to the critical issue of being linear only in a narrow strain range. Various strategies have been proposed to improve the performance of soft pressure sensors, but such a nonlinearity issue still exists and the sensors are only effective within a very narrow strain range. Herein, we fabricated a highly sensitive multi-channel pressure sensor array by using a simple thermal evaporation process of conducting nanomembranes onto a stretchable substrate. A rigid-island structure capable of dissipating accumulated strain energy induced by external mechanical stimuli was adopted for the sensor. The performance of the sensor was precisely controlled by optimizing the thickness of the stretchable substrate and the number of serpentines of an Au membrane. The fabricated sensor exhibited a sensitivity of 0.675 kPa−1 in the broad pressure range of 2.3–50 kPa with linearity (~0.990), and good stability (>, 300 Cycles). Finally, we successfully demonstrated a mapping of pressure distribution.
- Published
- 2021
4. Wireless Epidermal Electromyogram Sensing System
- Author
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Junho Choi, Sangyoup Lee, Jinseok Kim, Dong Hee Son, Duhwan Seong, Ki Jun Yu, Sangkyu Lee, Daewoong Lee, Minsu Jang, Sungjun Lee, and Jiyong Yoon
- Subjects
Computer Networks and Communications ,Computer science ,Powered exoskeleton ,Wearable computer ,lcsh:TK7800-8360 ,02 engineering and technology ,Substrate (printing) ,010402 general chemistry ,01 natural sciences ,Electronic engineering ,Wireless ,Electrical and Electronic Engineering ,Flexibility (engineering) ,Gait Disturbance ,business.industry ,lcsh:Electronics ,walking aids ,skin-attachable emg sensor ,021001 nanoscience & nanotechnology ,Line (electrical engineering) ,exoskeleton suit ,0104 chemical sciences ,wireless health monitoring ,Hardware and Architecture ,Control and Systems Engineering ,Signal Processing ,bio-medical engineering ,gait disturbance ,0210 nano-technology ,business ,Sensing system ,stretchable emg sensors - Abstract
Massive efforts to build walking aid platforms for the disabled have been made in line with the needs of the aging society. One of the core technologies that make up these platforms is a realization of the skin-like electronic patch, which is capable of sensing electromyogram (EMG) and delivering feedback information to the soft, lightweight, and wearable exosuits, while maintaining high signal-to-noise ratio reliably in the long term. The main limitations of the conventional EMG sensing platforms include the need to apply foam tape or conductive gel on the surface of the device for adhesion and signal acquisition, and also the bulky size and weight of conventional measuring instruments for EMG, limiting practical use in daily life. Herein, we developed an epidermal EMG electrode integrated with a wireless measuring system. Such the stretchable platform was realized by transfer-printing of the as-prepared EMG electrodes on a SiO2 wafer to a polydimethylsiloxane (PDMS) elastomer substrate. The epidermal EMG patch has skin-like properties owing to its unique mechanical characteristics: i) location on a neutral mechanical plane that enables high flexibility, ii) wavy design that allows for high stretchability. We demonstrated wireless EMG monitoring using our skin-attachable and stretchable EMG patch sensor integrated with the miniaturized wireless system modules.
- Published
- 2020
5. A Skin-Conformal, Stretchable, and Breathable Fiducial Marker Patch for Surgical Navigation Systems
- Author
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Sangkyu Lee, Sungjun Lee, Deukhee Lee, Hyoung Won Baac, Jiyong Yoon, Duhwan Seong, and Dong Hee Son
- Subjects
Low modulus ,skin-conformal ,Endoscope ,Computer science ,adhesive patch ,lcsh:Mechanical engineering and machinery ,Mechanical Engineering ,fiducial marker ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,augmented reality ,0104 chemical sciences ,surgical navigation systems ,Optical tracking ,Control and Systems Engineering ,Medical imaging ,lcsh:TJ1-1570 ,Augmented reality ,Electrical and Electronic Engineering ,0210 nano-technology ,Fiducial marker ,Biomedical engineering - Abstract
Augmented reality (AR) surgical navigation systems have attracted considerable attention as they assist medical professionals in visualizing the location of ailments within the human body that are not readily seen with the naked eye. Taking medical imaging with a parallel C-shaped arm (C-arm) as an example, surgical sites are typically targeted using an optical tracking device and a fiducial marker in real-time. These markers then guide operators who are using a multifunctional endoscope apparatus by signaling the direction or distance needed to reach the affected parts of the body. In this way, fiducial markers are used to accurately protect the vessels and nerves exposed during the surgical process. Although these systems have already shown potential for precision implantation, delamination of the fiducial marker, which is a critical component of the system, from human skin remains a challenge due to a mechanical mismatch between the marker and skin, causing registration problems that lead to poor position alignments and surgical degradation. To overcome this challenge, the mechanical modulus and stiffness of the marker patch should be lowered to approximately 150 kPa, which is comparable to that of the epidermis, while improving functionality. Herein, we present a skin-conformal, stretchable yet breathable fiducial marker for the application in AR-based surgical navigation systems. By adopting pore patterns, we were able to create a fiducial marker with a skin-like low modulus and breathability. When attached to the skin, the fiducial marker was easily identified using optical recognition equipment and showed skin-conformal adhesion when stretched and shrunk repeatedly. As such, we believe the marker would be a good fiducial marker candidate for patients under surgical navigation systems.
- Published
- 2020
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