Article
Engineering, Biomedical
Andrea Spanu, Alberto Botter, Andrea Zedda, Giacinto Luigi Cerone, Annalisa Bonfiglio, Danilo Pani
Summary: This research presents an optimized screen printing technique for the fabrication of textile electrodes based on PEDOT:PSS directly into stretchable garments, demonstrating good performance for dynamic sEMG detections. The results achieved pave the way for the integration of unobtrusive electrodes, obtained by screen printing of conductive polymers, into technical fabrics for rehabilitation and sport monitoring in dynamic conditions.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2021)
Article
Mechanics
Zhao Zhao, Yafei Yin, Xuanqing Fan, Yuhang Li
Summary: Stretchable heater, which can perfectly fit with undevelopable curved surfaces, has been developed. This study presents a new design of stretchable serpentine heater (SSH) that utilizes the embedded serpentine heat source in softer and highly stretchable materials to achieve high stretchability and thermal uniformity. The study also proposes an accurate theoretical model to predict the thermomechanical behaviors of SSH under large mechanical deformation, and investigates the effects of geometric parameters on its mechanical and thermal behaviors.
COMPOSITE STRUCTURES
(2022)
Article
Chemistry, Analytical
Bohdan Josypcuk, Jan Langmaier, Sofiia Tvorynska
Summary: Silver amalgam screen-printed electrodes (AgA-SPEs) were designed, prepared, and tested as representatives among SPEs for measuring at high negative potentials, showing superior PHE values compared to traditional silver-SPEs. The practical application of AgA-SPEs was demonstrated by analyzing iodine content in table salt, with consistent results as declared by the manufacturer.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Review
Chemistry, Multidisciplinary
Tao Cheng, Yi-Zhou Zhang, Shi Wang, Ya-Li Chen, Si-Ya Gao, Feng Wang, Wen-Yong Lai, Wei Huang
Summary: Stretchable self-healing supercapacitors offer improved durability and reliability, suitable for applications in smart wearable electronics. Conductive hydrogels, as electrode and electrolyte materials, possess unique structure and properties, showing great potential for achieving stretchable self-healing supercapacitors.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Ulrika Boda, Ioannis Petsagkourakis, Valerio Beni, Peter Andersson Ersman, Klas Tybrandt
Summary: The challenge of high-performance fully printed stretchable OECTs is addressed by developing fully screen-printed stretchable OECTs. Three stretchable functional screen-printing inks are developed, enabling the fabrication of OECTs. The stretchable OECTs show good characteristics and can withstand high strains. An electrochromic smart pixel is demonstrated by connecting a stretchable OECT to a stretchable electrochromic display. The development of screen-printed stretchable electrochemical devices, particularly OECTs, is believed to pave the way for their use in wearable applications and commercial products.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Chan Young Kim, Jun Ho Myung, Jeong-Yun Sun, Woong-Ryeol Yu
Summary: A polymer component in immiscible polymer blends leads to phase separation, resulting in different polymer morphologies depending on the weight ratio. This study demonstrates that a low weight fraction of a polymer component can form a continuous matrix phase, which is novel. Coating a solution of PEDOT:PSS blended with a high fraction of PDMS and a surfactant results in a continuous PEDOT:PSS matrix with spherical PDMS islands. The electrodes show excellent conductivity and stretchability, high transparency, and electromechanical stability.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Multidisciplinary
Jianxin Xu, Yang Li, Junyao Wang, Huan Liu, Qi Hou, Rui Wang, Tianhong Lang, Bowen Cui, Hongxu Pan, Yansong Chen, Jingran Quan, Hanbo Yang, Lixiang Li, Yahao Liu
Summary: Flexible power sources are crucial for developing flexible electronic systems, but their current poor stretchability and stability hinder their application in such devices. In this study, a flexible electrode with an arc-shaped star concave negative Poisson's ratio structure was fabricated to improve the stretchability and fatigue stability of flexible power sources. The electrode showed effective reduction of tensile stress and increased maximum elongation. Furthermore, all-solid-state symmetric supercapacitors assembled with these electrodes exhibited high areal capacitance and excellent stability.
Article
Chemistry, Multidisciplinary
Gargi Ghosh, Atanu Bag, Adeela Hanif, Montri Meeseepong, Yu Rim Lee, Nae-Eung Lee
Summary: Research on transient wearable electronics is gaining interest due to their ability to seamlessly conform to human tissues and disappear when disposed. However, the challenge lies in finding materials that are both biodegradable and stretchable. This study addresses these challenges by developing a biodegradable nanofiber-reinforced water-borne polyurethane with stretchability, toughness, and partial biodegradability. The research demonstrates the potential of these materials for use in transient wearable electronics.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Guoxuan Zhu, Hua Li, Meiling Peng, Guiyan Zhao, Jianwen Chen, Yutian Zhu
Summary: The study presents a new multimodal sensor based on porous conductive polymer composites, which demonstrates ultralow detection limit and ultrawide sensing range. The sensor has tremendous potentials in detecting strain, pressure, temperature, and even monitoring respiration.
Article
Chemistry, Analytical
R. Ivanov, C. Czibula, C. Teichert, M. Bojinov, V Tsakova
Summary: The study characterized five types of carbon-based screen-printed electrodes, finding differences in surface roughness and electrochemical properties, and further investigated them with electroless deposition of Pd.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Ying Liu, Chengcheng Xie, Wenbin Lai, Zhonggao Bu, Guangcong Zhang, Chengyi Xiao, Weiwei Li
Summary: This study presents a novel approach using composite inks based on silver nanowires to fabricate stretchable transparent electrodes(STEs). The STEs demonstrate low sheet resistance, facilitated surface roughness, strong adhesive strength, high transparency, remarkable stretchability, and exceptional thermal stability. Flexible organic solar cells employing this composite STE achieve outstanding performance.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Nanoscience & Nanotechnology
Dandan Pei, Chuanbin An, Bin Zhao, Mengke Ge, Zhongli Wang, Weijia Dong, Cheng Wang, Yunfeng Deng, Dongpo Song, Zhe Ma, Yang Han, Yanhou Geng
Summary: This article reports a stretchable semiconductor PU(DPP)(x) with large elastic recovery and high mechanical performance in thin film state, which shows potential for stretchable electronics.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Sehyun Park, Seunghyeb Ban, Nathan Zavanelli, Andrew E. Bunn, Shinjae Kwon, Hyo-ryoung Lim, Woon-Hong Yeo, Jong-Hoon Kim
Summary: Recent advances in soft materials and nano-microfabrication have made it possible to develop flexible wearable electronics. Printing technologies have shown efficiency and compatibility with polymeric materials for manufacturing wearable electronics. In this study, fully screen-printable, skin-conformal electrodes were presented for low-cost and scalable manufacturing of wearable electronics. The screen printing process enables easy, cost-effective, and high-throughput manufacturing, while the ink used for the conductive layer printing allows for natural deformation under stretching and bending conditions. Real-time wireless electrocardiogram monitoring was successfully demonstrated using the printed electrodes, with an algorithm developed for accurate heart rate and respiratory rate calculations, as well as arrhythmia detection.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Multidisciplinary
Hyeong-Min Sim, Yu-Kyung Oh, Yunjeong Yu, Sunkook Kim, Han-Ki Kim
Summary: Highly-stretchable and semi-transparent superlattice electrodes based on polytetrafluoroethylene (PTFE)/AgPdCu (APC)-PTFE were developed. The electrical and mechanical properties of the electrodes were optimized by controlling the PTFE thickness and the number of layers. The electrodes showed excellent mechanical stretchability and optical switching capability, making them suitable for stretchable electronics.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Chemistry, Physical
Andrew Claypole, James Claypole, Neil Bezodis, Liam Kilduff, David Gethin, Tim Claypole
Summary: The study demonstrates an innovative screen-printed Nanocarbon heater that is robust and flexible, capable of uniform heating. The device has low thermal inertia and rapid temperature response, reaching desired temperatures quickly. Screen printing can control the printed layer thickness, adjusting the heater performance.
Article
Materials Science, Ceramics
Chaeyoung Kang, Hae-Jun Seok, Seong-Won Kim, Mohadese Beigtan, Yunseok Kim, Han-Ki Kim
Summary: In this study, Ga and Ti co-doped In2O3 (IGTO) films were designed as flexible and transparent electrodes for thin film heaters (TFHs) and flexible touch screen panels (FTSPs) in automobiles. The IGTO electrodes deposited on cyclic olefin copolymer (COP) showed good properties in terms of sheet resistance, transmittance, and surface roughness. Moreover, the IGTO/COP samples exhibited mechanical flexibility and stable touch sensitivity. These findings suggest that IGTO/COP is a promising flexible and transparent electrode for curved TFHs and FTSPs in next-generation automobiles.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Multidisciplinary
Jihyun Kim, Myeongjin Jung, Dong Un Lim, Dongjoon Rhee, Sung Hyeon Jung, Hyung Koun Cho, Han-Ki Kim, Jeong Ho Cho, Joohoon Kang
Summary: Multi-valued logic gates are demonstrated on solution-processed molybdenum disulfide (MoS2) thin films by locally increasing the work function of MoS2 through a chemical doping process. Current levels and turn-on voltages for each state can be tuned by modulating the device geometries, eventually leading to the demonstration of various ternary logic gates.
Article
Chemistry, Multidisciplinary
Ju-Hyeon Lee, Vivekanandan Raman, Chaeyoung Kang, Hyun-Uk Ha, Hae-Jun Seok, Han-Ki Kim
Summary: In this study, a composite of PEDOT:PSS and Ag NW was demonstrated to enhance the stretchability of the Ag NW network electrode, with optimized ink ratios achieving good conductivity performance and a conductive bridge effect. Transparent electroluminescence devices and thin film heater devices fabricated using the AP electrode showed excellent performance, making it a suitable candidate for future wearable transparent devices.
Article
Chemistry, Multidisciplinary
Seong-Won Kim, Chaeyoung Kang, Han-Ki Kim
Summary: Transparent and flexible PTFE thin film passivation has been developed to prevent degradation of flexible IAI electrodes. Oxygen ion beam treatment improves the adhesion between the top ITO and PTFE passivation layer. The PTFE passivation maintains constant sheet resistance, transmittance, and flexibility, while the bare IAI electrode shows increased resistance and decreased transmittance and flexibility.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Physical
Shuai Lan, Saemon Yoon, Hae-Jun Seok, Hyeon Uk Ha, Dong-Won Kang, Han-Ki Kim
Summary: By fabricating flexible amorphous transparent V-doped In-Zn-O (IZVO) thin films at room temperature, the formation of oxygen vacancies was effectively suppressed, resulting in excellent electrical and optical properties. The IZVO electrode demonstrated superior performance in flexible perovskite solar cells, showing great potential for highly efficient flexible photovoltaic applications.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Hyunjin Park, Hyemin Kim, Sung Hyun Kim, Eunmi Cho, Han-Ki Kim, Sang-Jin Lee
Summary: In this study, a transparent and flexible heater using PPFC/Ag bilayer thin films was successfully fabricated. The bilayer thin film structure improved the optical transmittance while simplifying the process. The optimized bilayer thin film exhibited good performance and can be used in flexible and rollable devices to prevent frosting and fogging.
Article
Materials Science, Ceramics
Seo Hyoung Park, Yu-Kyung Oh, Ye-Ju Lim, Shaozheng Chen, Sang-Jin Lee, Han-Ki Kim
Summary: We investigated the characteristics of F-doped SnO2 (FTO)/Ag/FTO films prepared using thermal evaporation at room temperature for the application of transparent thin film heaters (TFHs) in automobiles. By optimizing the thickness of Ag and FTO layers, we achieved a FTO/Ag/FTO electrode with desirable electrical and optical properties, including a sheet resistance of 8.00 Ohm/square, an optical transmittance of 83.04% at a visible wavelength, and a figure of merit (FoM) value of 19.49 Ohm-1. The TFHs using this electrode demonstrated thermally stable performances and a low operating direct current of 6 V.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Hae-Jun Seok, Ahra Yi, Hanbin Lee, Hyo Jung Kim, Han-Ki Kim
Summary: This study compared the properties of artificially preferred (222) and (400) ITO electrodes and found that the (222) preferred ITO electrode with larger grain size of MAPbI3 active layer, lower sheet resistance, and higher optical transmittance resulted in higher power conversion efficiency for planar-type perovskite solar cells.
JOURNAL OF POWER SOURCES
(2022)
Article
Materials Science, Multidisciplinary
Hyeon Uk Ha, Hae-Jun Seok, Saemon Yoon, Dong -Gun Lee, Dong-Won Kang, Han -Ki Kim
Summary: In this study, the effect of target-to-substrate distance (TSD) on the performance of ST-PSCs during linear facing target sputtering (LFTS) was investigated. An optimal TSD of 6 cm was determined, which resulted in a high-quality amorphous IGTO film with excellent electrical and optical properties. The ST-PSCs constructed using the optimized IGTO upper cathode exhibited high performance without plasma damage.
Article
Chemistry, Physical
Hae-Jun Seok, Jung-Min Park, Jaehoon Jeong, Shuai Lan, Doh-Kwon Lee, Han-Ki Kim
Summary: We developed an isolated plasma soft deposition (IPSD) technique to deposit a Sndoped In2O3 (ITO) top cathode on semi-transparent perovskite solar cells (PSCs) without plasma damage. The IPSD process prevents direct irradiation of plasma and facilitates plasma damage-free sputtering. The IPSD-processed ITO film exhibited excellent properties and a similar power conversion efficiency to magnetron-sputtered ITO cathodes.
Article
Chemistry, Multidisciplinary
Chaeyoung Kang, Seong-Won Kim, Wook Kim, Dukhyun Choi, Han-Ki Kim
Summary: Snake-skin-patterned electrodes are developed by combining Kirigami structure and biomimicry, showing high stretchability and excellent biocompatibility. Finite element analysis simulations are used to optimize the snake skin patterns for the most stretchable structure. The electrodes exhibit better stretchability and stable conductivity even at high strains, making them suitable for wearable sensors and devices.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Ju-Hyeon Lee, Tae-Yang Choi, Ho-Sung Cheon, Hye-Young Youn, Gun-Woo Lee, Sung-Nam Lee, Han-Ki Kim
Summary: We demonstrated the conformal Al2O3 passivation of a flexible Ag network electrode using atomic layer deposition (ALD). The ALD-grown Al2O3 film maintained the optical transmittance and mechanical flexibility of the Ag network electrode. The Al2O3 passivation provided improved stability and reliability compared to the bare Ag network electrode, making it a promising material for high quality Ag network electrodes with high aspect ratios.
Article
Materials Science, Multidisciplinary
Yong Jun Kim, Seo-Yun Choi, Hak Shin, Han-Ki Kim
Summary: Korean traditional paper, Hanji, is combined with Ag nanowires to create multi-functional paper windows for traditional Korean houses. The handmade Hanji contains embedded Ag nanowires, forming a percolating network structure with a low sheet resistance of 28 Ohm square(-1), suitable for interconnectors and electrodes. The flexibility of the Hanji and Ag nanowires allows for outstanding mechanical flexibility, making it ideal for curved or flexible electronic paper windows. The Hanji also exhibits antibacterial properties and electromagnetic interference shielding due to the existence of metallic Ag nanowires. The successful operation of various devices using Hanji-based interconnectors demonstrates its potential as a device-integrated paper window for traditional Korean houses.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Engineering, Electrical & Electronic
Seong-Won Kim, Chaeyoung Kang, Tae-Yang Choi, Jong-Woong Kim, Han-Ki Kim
Summary: Researchers developed conformal polytetrafluoroethylene (PTFE) passivation thin films to address the rapid degradation of MXene-Ag nanowire (MA) composite transparent conductive electrodes (TCEs) in ambient and humid conditions. The PTFE passivated electrode showed improved stability and prevented moisture and impurity penetration, maintaining constant sheet resistance, transmittance, flexibility, and EMI SE even after harsh testing. This study highlights the importance of developing protective coatings for enhancing the performance and durability of TCEs.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Ju-Hyeon Lee, Jung-Min Park, Yu Jung Park, Jung Hwa Seo, Han-Ki Kim
Summary: In this study, TiN was used as a carrier suppressor in an amorphous InZnO channel to achieve stable channels for TFTs and LETs. TiN doping effectively reduced the number of oxygen vacancies in the InZnO channel and decreased excess electrons. The TiN-doped InZnO channel exhibited an amorphous structure and improved stability. Additionally, TiN doping in the InZnO channel enhanced the intensity of LET devices by preventing exciton quenching caused by oxygen vacancies.
ACS APPLIED MATERIALS & INTERFACES
(2023)
