Article
Materials Science, Multidisciplinary
Kory Schlingman, Gloria M. D'Amaral, R. Stephen Carmichael, Tricia Breen Carmichael
Summary: Liquid metal-embedded elastomers (LMEEs) are deformable composites made of liquid metal particles dispersed in an elastomeric matrix. A simple process is introduced to fabricate intrinsically conductive LMEEs with conductive surfaces by sedimenting microparticles of eutectic gallium-indium alloy in the elastomer. These materials are soft, stretchable, and exhibit stable conductivity.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Engineering, Environmental
Zhengyou Zhu, Congcong Liu, Fengxing Jiang, Jing Liu, Guoqiang Liu, Xiumei Ma, Peipei Liu, Rui Huang, Jingkun Xu, Lei Wang
Summary: A novel fiber-shaped hydrogen sensor with excellent mechanical properties and sensing performance has been developed in this study, showing potential for wearable sensor devices and providing a smart sensor design strategy for the development of wearable electronics.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Instruments & Instrumentation
Marco Chu, Hani E. Naguib
Summary: This study assessed the performance of various conductive composite polymers in collecting electrical signals from the heart, and found that adding 5% carbon nanotubes significantly increased the elastic modulus and conductivity of the composites. SBS-CNT composites at 5% and 10% showed the best performance in detecting ECG waves from the heart.
SMART MATERIALS AND STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Wangkai Jiang, Tingting Li, Bilqees Hussain, Suibo Zhou, Zheshan Wang, Yu Peng, Jianchen Hu, Ke-Qin Zhang
Summary: In this study, scalable and high-performance carbon nanotube composite yarns were developed by using multi-wall carbon nanotubes and single-wall carbon nanotubes as thermoelectric materials. These yarns were then treated to obtain p- and n-type segmented structures, and combined to fabricate a thermoelectric textile with outstanding performance. This textile was able to generate a high power density of 95.74 μW·m(-2) and a high voltage density of 3.76 V·m(-2) at a temperature difference of 32 K, showing great potential for electronic device applications after amplification.
ADVANCED FIBER MATERIALS
(2023)
Article
Materials Science, Composites
Sirui Tan, Junsheng Wang, Wanhui Jin, Qian Zhang, Zhong Zhao, Daiqi Li, Deshan Cheng, Shuguang Bi, Jianhua Ran, Guangming Cai, Xin Wang
Summary: This article presents a scalable and simple method for fabricating liquid metal (LM)/carbon nanotubes (CNTs) @Ecoflex (LCEF) coaxial conductive filaments. The electro-mechanical response of the filaments was investigated, showing their capability for monitoring both large and subtle human motions. Additionally, the LCEF fabrics demonstrated efficient electrothermal response, functioning as large-area flexible heaters. This work contributes to the scalable fabrication of flexible strain sensors and electrothermal devices, paving the way for the development of multifunctional wearable electronic devices.
COMPOSITES COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Lijun Ma, Xiao Lei, Shifeng Li, Shuailong Guo, Jun Yuan, Xiaotian Li, Gary J. Cheng, Feng Liu
Summary: A novel surface-filled graphene nanosheets (GNs) conductive layer was utilized to fabricate a highly sensitive, stable and 3D flexible piezoresistive sensor, showing promising potentials in wearable electronics. Compared to surface-coated GNs sensors, the surface-filled GNs sensor exhibited better stability and higher sensitivity, indicating its great potential for health monitoring applications.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Engineering, Biomedical
Yuanyuan Han, Lu Sun, Chenyu Wen, Zhaohui Wang, Jianwu Dai, Liyang Shi
Summary: A conductive hydrogel composed of silk hydrogel and conducting polymer was developed, showing high conductivity and sensitive response to conformation changes. It was used to fabricate flexible and wearable strain sensors for monitoring various body movements.
BIOMEDICAL MATERIALS
(2022)
Review
Chemistry, Multidisciplinary
Vicente Orts Mercadillo, Kai Chio Chan, Mario Caironi, Athanassia Athanassiou, Ian A. Kinloch, Mark Bissett, Pietro Cataldi
Summary: There is a growing interest in transitioning electronic components and circuitry to more flexible and stretchable platforms. The development of conductive inks with novel nanomaterials, such as graphene and MXenes, has led to the creation of new flexible electronic devices with exciting applications in the wearable, healthcare and Internet of Things sectors. Despite their different chemical origins, graphene and MXenes share similar electrical properties and 2D morphology, guaranteeing intriguing performance in end applications.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Shanshan Zhao, Juan Chen, Jingyu Zhou, Shangxuan Shi, Miao Hou, Bin Sheng
Summary: The study presents a superelastic conductive fractal helix fiber (FHF) made of thermoplastic polyurethane fiber and Ag wire, which has excellent waterproofing ability. By increasing the helical index C and Ag wire winding density, the maximum strain of the FHF can be improved to 8300%. It exhibits high conductivity (6.3 x 10(7) S m(-1)) and ultra-high Q value (3.37 x 10(4)) at a strain of 5600%.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Physical
Zakhar Ivanovich Evseev, Fedora Dmitrievna Vasileva, Svetlana Afanasyevna Smagulova, Petr Stanislavovich Dmitriev
Summary: Cotton e-textiles were produced using two different types of graphene oxide. The first type was synthesized using the Hummers' method, while the second type was obtained through electrochemical exfoliation of graphite. It was found that e-textiles based on electrochemically exfoliated graphene had higher electrical conductivity and better washing and mechanical stress stability compared to those based on Hummers' method graphene oxide. The superior properties of electrochemically exfoliated graphene were attributed to its smaller lateral size and higher degree of sp(2) structure regeneration after reduction.
Article
Materials Science, Multidisciplinary
Fahad Alshabouna, Hong Seok Lee, Giandrin Barandun, Ellasia Tan, Yasin Cotur, Tarek Asfour, Laura Gonzalez-Macia, Philip Coatsworth, Estefania Nunez-Bajo, Ji-Seon Kim, Firat Guder
Summary: The textile industry has advanced processes for manufacturing garments with precise visual patterns. However, it lacks the capability to fabricate clothes with seamlessly integrated wearable sensors due to the lack of conductive threads compatible with standard manufacturing methods. In this study, we developed a low-cost conductive thread that is compatible with computerized embroidery. We successfully produced wearable electrical sensors, including a facemask for monitoring breathing and a t-shirt for monitoring heart activity, using this conductive thread. This development has the potential to enable mass manufacturing of low-cost wearable sensors integrated into everyday clothes.
Article
Nanoscience & Nanotechnology
Huijun Chen, Huimin Xu, Mengying Luo, Wen Wang, Xing Qing, Ying Lu, Qiongzhen Liu, Liyan Yang, Weibing Zhong, Mufang Li, Dong Wang
Summary: In this study, a highly conductive, ultrastrong, and flexible PEDOT:PSS/EMIM:DCA fiber was prepared by wet-spinning and subsequent sulfuric acid-immersion-drawing process. The fiber exhibited excellent properties such as high tensile strength and low Young's modulus, which were attributed to the removal of PSS and high crystallinity and orientation of PEDOT. Various flexible and wearable electronic devices were constructed based on the P/ED fiber.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Review
Materials Science, Multidisciplinary
Abbas Ahmed, Sudeep Sharma, Bapan Adak, Md Milon Hossain, Anna Marie LaChance, Samrat Mukhopadhyay, Luyi Sun
Summary: This article reviews the latest developments in MXene-enabled flexible electronics for wearable electronics, highlighting several nanoscale MXene-enabled electronic devices and their applications in healthcare, energy, electromagnetic interference shielding, and humanoid control of machines.
Article
Chemistry, Physical
Jinlei Miao, Tingting Fan
Summary: With the emergence of smart wearable electronics, the demand for flexible and stretchable transparent conductive electrodes (TCEs) has increased. Graphene, a novel two-dimensional carbon material, has unique properties that make it an ideal candidate for elastic TCEs. This review comprehensively summarizes the advancements in graphene-based elastic TCEs and discusses the strategies and mechanisms for achieving high mechanical flexibility and transparency.
Review
Chemistry, Multidisciplinary
Jiajun Song, Hong Liu, Zeyu Zhao, Peng Lin, Feng Yan
Summary: Flexible and stretchable biosensors are increasingly utilized for acquiring high-fidelity signals in emerging applications. Organic thin film transistors (OTFTs) are ideal candidates for flexible and stretchable biosensing due to their soft nature, amplification function, biocompatibility, functionalization ease, low cost, and device diversity. This review provides a comprehensive overview of the advancements in flexible-OTFT-based biosensors, discussing their features, functionalization strategies, applications in wearable, implantable, and portable electronics, as well as neuromorphic biointerfaces. Special attention is given to emerging stretchable organic transistors and their engineering routes for achieving stretchability, along with their implementations in e-skin and smart textiles. The remaining challenges and future opportunities in this field are also summarized.
ADVANCED MATERIALS
(2023)
Article
Agriculture, Dairy & Animal Science
Ruoyu Chen, Yuliang Zhao, Yongliang Yang, Shuyu Wang, Lianjiang Li, Xiaopeng Sha, Lianqing Liu, Guanglie Zhang, Wen Jung Li
Summary: In order to efficiently characterize carcasses of domestic birds in China, a noncontact and automated weighing method was developed. The weight of the duck carcasses was estimated using a convolutional neural network model trained on acquired images. Our model showed improved accuracy compared to existing methods.
Article
Multidisciplinary Sciences
Donghai Yang, Yifan Liu, Qingjiu Chen, Meng Chen, Shaodong Zhan, Nim-kwan Cheung, Ho-Yin Chan, Zhidong Wang, Wen Jung Li
Summary: Light detection and ranging (LiDAR) has been widely used in various fields, such as robotics navigation, autonomous vehicles, unmanned aerial flyers, and land surveying. The multichannel LiDAR system is important for autonomous driving due to its larger field of view (FoV). However, the number of transceivers limits the vertical angular resolution of multichannel LiDAR systems and makes them costly. The emergence of microelectromechanical systems (MEMS) mirrors may provide a low-cost and high-angular resolution solution for LiDAR systems.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Baobing Fan, Wei Gao, Rui Zhang, Werner Kaminsky, Francis R. Lin, Xinxin Xia, Qunping Fan, Yanxun Li, Yidan An, Yue Wu, Ming Liu, Xinhui Lu, Wen Jung Li, Hin-Lap Yip, Feng Gao, Alex K. -Y. Jen
Summary: Organic photovoltaics (OPVs) have made significant progress recently, thanks to the use of well-designed non-fullerene acceptors (NFAs) with conjugated side-groups. Researchers have developed a new class of NFAs with localisomerized conjugated side-groups and studied their impact on device performance and stability. A device based on one of the isomers achieved an impressive efficiency of 18.5% and exhibited excellent photo- and thermal stability. A similar approach was applied to another polymer donor, resulting in an even higher efficiency of 18.8%. This work highlights the effectiveness of local isomerization in enhancing the photovoltaic performance and stability of OPVs based on fused ring NFAs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Shengfan Wu, Jie Zhang, Minchao Qin, Fengzhu Li, Xiang Deng, Xinhui Lu, Wen-Jung Li, Alex K. -Y. Jen
Summary: By incorporating a cross-linkable organic ligand into the perovskite precursor solution, the facet orientation of polycrystalline perovskite films can be controlled, leading to enhanced performance of perovskite-based devices. The resulting low-dimensional perovskites (LDPs) can passivate defects and improve the efficiency and stability of perovskite solar cells (PSCs), with power conversion efficiencies (PCE) of 24.12% (rigid) and 23.23% (flexible). Furthermore, the ligand enables the derived LDPs to be crosslinked, enhancing the mechanical bending durability of flexible devices.
Article
Multidisciplinary Sciences
Vaithinathan Karthikeyan, James Utama Surjadi, Xiaocui Li, Rong Fan, Vaskuri C. S. Theja, Wen Jung Li, Yang Lu, Vellaisamy A. L. Roy
Summary: For decades, thermoelectric generators have been limited by heat stagnation and brittleness, which hampers power conversion efficiency and durability. However, by utilizing a cellular architecture with enhanced thermal impedance and partial carbonization for strength and ductility, we have developed 3D architected thermoelectric generators that exhibit high energy absorption and power conversion efficiency. Our work seeks to improve future thermoelectric generator designs by combining excellent thermoelectric properties with mechanical robustness through additive manufacturing.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Weijia Wang, Maria Merlyne De Souza, Rami Ghannam, Wen Jung Li, Vellaisamy A. L. Roy
Summary: The miniaturization and integration of sensors on a chip is crucial for the advancements of artificial intelligence and the Internet of Things. Current microbend optical stress sensors are too large to be integrated on a chip, thus requiring a fundamental change in structural design for micron-sized lithography. In this study, we present the design and analysis of a multi-layer microbend optical stress sensor using an advanced Multiphysics simulation model. The optimized structure and materials of the sensor architecture result in high sensitivity and linearity, paving the way for embedding microbend optical stress sensors on chips for communication and information technologies.
JOURNAL OF COMPUTATIONAL ELECTRONICS
(2023)
Article
Chemistry, Multidisciplinary
Dani S. Assi, Hongli Huang, Vaithinathan Karthikeyan, Vaskuri C. S. Theja, Maria Merlyne de Souza, Ning Xi, Wen Jung Li, Vellaisamy A. L. Roy
Summary: Neuromorphic artificial intelligence systems are the future of ultrahigh-performance computing clusters. Quantum topological neuristors (QTN) with low energy consumption and higher switching speed are introduced to mimic the synapses of mammalian brains. With improved design, QTNs demonstrate top-notch neuromorphic behavior and can be interfaced with artificial neural networks for decision-making operations.
Article
Materials Science, Multidisciplinary
Wen-Jung Li, Kwang-Lung Lin
Summary: The possibility of monitoring the mechanical property, Vickers hardness, of Inconel 600 alloy with electric current stressing was investigated. A combined parameter tD/N, which is the product of current stressing duration tD and current stressing cycle N, was used as the control factor. By appropriately controlling the combined parameter and current stressing density of 7 x 103 A/cm2, a maximum enhancement of microhardness by 19.5% compared to the heat treated benchmark specimen was achieved. The study examined the strengthening mechanism through various techniques including EBSD, XRD, and HRTEM, focusing on grain orientation, grain size, phase transformation, precipitation, and dislocation. A maximum dislocation density of 5 x 1016 m-2 in the 111 direction was observed at ln(tD/N) of -0.69. The enhancement in microhardness was attributed to strain hardening caused by dislocation formation during current stressing.
Review
Engineering, Manufacturing
Jianfei Wang, Jiao Suo, Zhengxun Song, Wen Jung Li, Zuobin Wang
Summary: Nanomaterial-based flexible sensors (NMFSs) are versatile tools for monitoring human physiological information, providing medical data, and exploring metaverse spaces. The use of various nanomaterial frameworks, such as nanoparticles, nanowires, and nanofilms, has advanced the development of NMFSs. Additionally, different triggering interaction interfaces between NMFSs and metaverse/VR applications, as well as the application of machine learning algorithms for virtual interaction technologies, have been discussed in this review.
INTERNATIONAL JOURNAL OF EXTREME MANUFACTURING
(2023)
Article
Computer Science, Information Systems
Meng Chen, Hui Fang Szu, Hsin Yen Lin, Yifan Liu, Ho-Yin Chan, Yufan Wang, Yuliang Zhao, Guanglie Zhang, Jeffrey Da-Jeng Yao, Wen Jung Li
Summary: This study utilized a smart Internet of Things wristband motion sensor and a phase-based feature selection method to implement data-based sports performance evaluation for improving athlete's skills. By analyzing and identifying the skill levels of volleyball serves using machine learning algorithms, the researchers were able to assess the quality of motions. They also extracted performance metrics based on biomechanical principles to provide feedback and training suggestions to coaches and players, aiming to enhance future performances.
IEEE INTERNET OF THINGS JOURNAL
(2023)
Article
Automation & Control Systems
Yuliang Zhao, Tianang Sun, Zhongjie Ju, Fanghecong Dong, Le Yang, Xiaoyong Lv, Chao Lian, Meng Chen, Wen Jung Li
Summary: In this article, a new time-series skeleton joint data imaging method is introduced into an improved convolutional neural network to address the limitations of traditional methods in terms of computations and holistic learning of human skeletal sequences. Experimental results show that the method achieves an impressive accuracy of 98.02% in recognizing 25 daily human activities.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Engineering, Electrical & Electronic
Chao Lian, Yiming Yang, Xiaodong Yu, Hui Sun, Yuliang Zhao, Guanglie Zhang, Wen Jung Li
Summary: Arrhythmia is a significant symptom of cardiovascular diseases and accurately measuring heart rate is crucial for its detection. This study proposes a method that uses a smartphone camera to accurately measure human heart rate. By employing signal fusion, region of interest selection, and fast Fourier transform analyses, the method achieves a 95.84% detection rate compared to electrocardiography measurements.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Nanoscience & Nanotechnology
Ka Wai Kong, Keer Wang, Alice Yeuk Lan Leung, Hongyu Zhang, Jiao Suo, Meng Chen, Guanglie Zhang, Fei Fei, Jiangang Shen, Wen Jung Li
Summary: We present a new flexible capacitive pressure-pulse sensor array that combines droplet-dispensed graphene oxide (GO) sensing elements with flexible electronics. The use of droplet dispensing technology allows for the rapid fabrication of multiple capacitive sensing elements, resulting in highly sensitive pressure sensors with excellent repeatability. Preliminary characterization shows that these sensors have a sensitivity of approximately 10(-3) kPa(-1) and a relative permittivity of around 6 at a frequency of 600 kHz. Moreover, the printed sensing elements have been successfully used for human wrist pulse sensing. This technology has the potential to be applied in wearable electronics for healthcare applications.
IEEE OPEN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Automation & Control Systems
Yifan Liu, Meng Chen, Chishing Chan, Ho-yin Chnnan, Jianping Wang, Xinge Yu, Xinyue Li, Wen Jung Li
Summary: This article introduces a wireless IoT motion sensor weighing only 2g, which can be attached to mice to collect continuous motion data for multiple days. It also presents a combined segmentation method and imbalanced learning process for recognizing common and random mouse behaviors in cages, achieving a macro-recall rate of 94.55%.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Automation & Control Systems
Rui Liu, Yudi Zhu, Cong Wu, Hao Guo, Wei Dai, Tianyi Wu, Min Wang, Wen Jung Li, Jun Liu
Summary: Cell counting is an essential step in many biomedical applications, but the traditional microscopic cell counting method is time-consuming and prone to errors. To address these challenges, we propose an interactive dual-network framework that utilizes deep learning to automatically count cells. The framework trains a deep learning model to regress a density map from a given microscope image, and the number of cells can be estimated by integrating over the density map. We also design a hierarchical multi-scale attention-based architecture to accurately regress high-quality density maps. Evaluation experiments demonstrate the superiority of our method.
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
(2023)
