npj Flexible Electronics最新文献

{"title":"Reusable free-standing hydrogel electronic tattoo sensors with superior performance","authors":"Shuyun Zhuo, Alexandre Tessier, Mina Arefi, Anan Zhang, Chris Williams, Shideh Kabiri Ameri","doi":"10.1038/s41528-024-00335-x","DOIUrl":"10.1038/s41528-024-00335-x","url":null,"abstract":"Recently electronic tattoo sensors have attracted immense interest for health monitoring mainly due to their higher sensing performance than conventional dry sensors, owing to the ultra-low thickness which results in their conformability to the skin. However, their performance is worse than wet sensors. Further, these electronic tattoo sensors are not durable and reusable when free-standing because of their low thickness and being too delicate. Here, we report a remarkably high-performance freestanding, reusable, ultrathin and ultra-soft electronic tattoo sensor made of parylene-hydrogel double layer system with high water retention over extended periods that can be used for the extended period of 6 months. The hydrogel electronic tattoo (HET) sensors consist of electrically conductive self-adhesive hydrogel with a thickness of 20 µm and Young’s modulus of only 31 kPa at 37 °C, allowing for ultra-conformal contact to the skin microscopic features. Our HET sensors are fabricated using a scalable cost-effective method on ordinary tattoo papers and are laminated on the skin like temporary tattoos and were used for electrophysiological signals recording such as electrocardiography (ECG), electromyography (EMG), and skin hydration, temperature sensing. The HET sensors, for the first time, show 234% lower sensor-skin interface impedance (SSII) and significantly lower susceptibility to motion than gold standard medical grade silver/silver chloride wet gel electrodes which are known to have the lowest SSII and susceptibility to motion. Further, the low HET-skin interface impedance leads to a considerably larger signal amplitude and signal-to-noise ratio (SNR) of the electrophysiological signals recorded using HET sensors in comparison with those obtained using gold standard medical grade silver/silver chloride wet gel electrodes. The SNR of some types of electrophysiological signals such as EMG recorded using HET is up to 19 dB higher than gold standard medical grade electrodes due to higher signal amplitude, significantly lower susceptibility of HET to motion and lower motion artifacts. Also, the HET sensor is the first free-standing ultrathin tattoo sensor that can be transferred from the skin to tattoo paper and vice versa many times and the electrophysiological sensing quality remained high during repeated use for over 6 months.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-11"},"PeriodicalIF":12.3,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00335-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141880286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A kirigami-based reconfigurable metasurface for selective electromagnetic transmission modulation","authors":"Shuchang He, Chengjun Wang, Jie Tao, Haishan Tang, Zuojia Wang, Jizhou Song","doi":"10.1038/s41528-024-00334-y","DOIUrl":"10.1038/s41528-024-00334-y","url":null,"abstract":"Tunable three-dimensional (3D) electromagnetic metasurfaces are essential for achieving selective modulation of polarized waves, but they usually require complex designs and the use of smart materials, posing great implementation challenges. Here, we propose a novel kirigami-based reconfigurable electromagnetic metasurface, which consists of a kirigami-based deformable thin polyimide substrate and periodically arranged copper split-ring resonators. By simple stretch, the two-dimensional (2D) planar metasurface can be uniformly transformed into a 3D state, enabling it to effectively and selectively modulate linearly and circularly polarized waves. Experimental and numerical results reveal the mechanical deformation and transmission characteristics of the metasurface under applied strains. It is shown that the metasurface exhibits good selective transmission tunability while the resonant frequency remains basically unchanged for both transverse electric and transverse magnetic polarized waves. Furthermore, the selective tuning mechanism and the influence of geometrical parameters are also illustrated by the equivalent circuit analysis.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-9"},"PeriodicalIF":12.3,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00334-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141877669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-precision flexible sweat self-collection sensor for mental stress evaluation","authors":"Chenhao Wang, Zhengyu Wang, Wei Wei, Zhenjie Zhang, Anne Ailina Li, Guanghao Huang, Xian Li, Shuzhi Sam Ge, Lianqun Zhou, Hui Kong","doi":"10.1038/s41528-024-00333-z","DOIUrl":"10.1038/s41528-024-00333-z","url":null,"abstract":"As a stress hormone existing in the human body, cortisol can reflect the psychological stress and health status in daily life, and is a potential biomarker of the body’s stress response. To effectively collect sweat and accurately identify the target, this paper reports a flexible wearable cortisol detection device with outstanding reliability and sensitivity. Molecular imprinted polymer (MIP) ensures cortisol specificity. And carbon nanotubes (CNT) on electrodes increase sensitivity, expanding the detection range to 10−3 to 104 nM, with sensitivity at 189.2 nA/lg(nM). In addition, porous chitosan hydrogel (PCSH) collects sweat effectively, its adhesive properties and 80% swelling rate offer a low-cost alternative to microfluidics. Flexible printed circuit board (FPCB) and serpentine electrode (SE) ensure device durability. This non-invasive, highly sensitive device offers a novel method for mental stress monitoring and clinical diagnosis, advancing human physiological state monitoring.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-10"},"PeriodicalIF":12.3,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00333-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141790982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailored molecular for ultra-stability and biocompatible pseudohalide metal-free perovskite towards X-ray detectors with record sensitivity","authors":"Yutian Lei, Mengying Yin, Chang Shi, Lingxi Wu, Guoqiang Peng, Youkui Xu, Haoxu Wang, Rongbing Tang, ZhenHua Li, Zhiwen Jin","doi":"10.1038/s41528-024-00330-2","DOIUrl":"10.1038/s41528-024-00330-2","url":null,"abstract":"The emerging pseudohalide metal-free perovskite (pseudohalide–MFPs) X-ray detector caters to the demands of timely mobile diagnosis owing to its lightweight, flexibility, and cost-effectiveness. However, the performance of these devices is severely limited by poor X-ray absorption, ultra-wide band gap, relative instability, and their unknown biotoxicity. Herein, we construct heavy atom covalent bonds (C–Br/Cl) on the A-site organic cation to reinforce component coordination to modulate X-ray absorption and band gap in pseudohalide–MFPs and further enhance its stability. Molecular dynamics simulations demonstrate that the introduction of halogen atoms can strengthen hydrogen bonding interactions, thereby improving the coordination between different components. The resultant (MDABCOBr)–NH4(BF4)3 (MDABCO = N-methyl-N’-diazabicyclo[2.2.2]octonium) single crystal significantly increases X-ray absorption cross-section and crystalline density (from 1.728 to 1.950 g cm−3), and synergistically realizes the band nature modulation (from 7.4 to 5.5 eV) and enhanced ionic migration inhibition (628 meV) with optimized stability. As such, our X-ray detectors realized a sensitivity of 2377 μC Gyair−1 cm−2, an ultralow detection limit of 50.1 nGyair s−1, and impressive operation stability. Moreover, cytotoxicity assay confirmed the compatibility of pseudohalide metal-free perovskite. Finally, within this framework, we successfully fabricate the (MDABCOBr)–NH4(BF4)3-based flexible device to create an ideal in vitro wearable X-ray detection.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-10"},"PeriodicalIF":12.3,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00330-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141791124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Room temperature compressed air-stable conductive copper films for flexible electronics","authors":"H. Jessica Pereira, Oleg Makarovsky, David. B. Amabilino, Graham N. Newton","doi":"10.1038/s41528-024-00331-1","DOIUrl":"10.1038/s41528-024-00331-1","url":null,"abstract":"The state-of-the-art technology of fabricating printed copper electronics is focussed largely on thermal sintering restricting transition towards heat sensitive flexible substrates. Herein we report a pioneering technology which eliminates the need for conventional sintering. Biopolymer-stabilised copper particles are prepared such that they can be compressed at room temperature to generate air-stable films with very low resistivities (2.05 – 2.33 × 10−8 Ω m at 20 °C). A linear positive correlation of resistivity with temperature verifies excellent metallic character and electron microscopy confirms the formation of films with low porosity (< 4.6%). An aqueous ink formulation is used to fabricate conductive patterns on filter paper, first using a fountain/dip pen and then printing to deposit more defined patterns (R < 2 Ω). The remarkable conductivity and stability of the films, coupled with the sustainability of the approach could precipitate a paradigm-shift in the use of copper inks for printable electronics.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-12"},"PeriodicalIF":12.3,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00331-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexible adaptive sensing tonometry for medical-grade multi-parametric hemodynamic monitoring","authors":"Mengkang Deng, Chentao Du, Jiayuan Fang, Changshun Xu, Chenhui Guo, Jiantao Huang, Kang Li, Lei Chen, Yuan-Ting Zhang, Yu Chang, Tingrui Pan","doi":"10.1038/s41528-024-00329-9","DOIUrl":"10.1038/s41528-024-00329-9","url":null,"abstract":"Continuous hemodynamic monitoring in a wearable means can play a crucial role in managing hypertension and preventing catastrophic cardiovascular events. In this study, we have described the fully wearable tonometric device, referred to as flexible adaptive sensing tonometry (FAST), which is capable of continuous and accurate monitoring of hemodynamic parameters within the medical-grade precision. In particular, the FAST system integrates a 1 × 8 unit array of highly sensitive and highly flexible iontronic sensing (FITS) with 1 mm spatial resolution and a closed-loop motion system. The flexible tonometric architecture has been used to determine the radial arterial position with high sensitivity and high conformability, which simplifies the biaxial searching process of the traditional applanation tonometry into a highly efficient uniaxial applanation while keeping the medical-precision assessments. Importantly, a self-calibration algorithm can be automatically implemented during the applanation process, from which the intra-arterial blood pressure wave can be continuously predicted within the medical-grade precision, and subsequently, multi-parametric hemodynamic analysis can be performed in real-time. Experimental validations on health volunteers have demonstrated that the FAST measurements are all within the required accuracy of the clinical standards for continuous pulse wave assessments, blood pressure monitoring as well as other key hemodynamic parameter evaluations. Therefore, the FAST system, by integrating the flexible iontronic sensing array, provides a real-time, medical-grade hemodynamic monitoring solution in a continuously wearable manner, from which remote patient-centered monitoring can be delivered with both medical precision and convenience.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-16"},"PeriodicalIF":12.3,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00329-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intrinsically stretchable OLEDs with a designed morphology-sustainable layer and stretchable metal cathode","authors":"Je-Heon Oh, Kun-Hoo Jeon, Jin-Woo Park","doi":"10.1038/s41528-024-00332-0","DOIUrl":"10.1038/s41528-024-00332-0","url":null,"abstract":"The development of wearable devices has increased the need for organic light-emitting diodes (OLEDs) that are soft, stretchable, and can integrate seamlessly with the human body. Traditional intrinsically stretchable OLEDs (is-OLED) often suffer from reduced performance due to orthogonal solvent problem and lamination fabrication process, which can cause defects and delamination. To overcome these challenges, we developed a sequentially coated is-OLED and confirmed the maintenance of the designed morphologies of each layer and a highly stretchable metallic is-cathode. Our is-OLEDs achieved a maximum total luminance of 3151 cd m–2 and a total current efficiency of 5.4 cd A–1. It also demonstrated superior durability, with the ability to stretch up to 70% and maintain 80% luminance after 300 cycles at 40% strain. This advancement suggests a promising future for durable and efficient soft electronic devices.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-10"},"PeriodicalIF":12.3,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00332-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stabilizing Schottky junction in conjugated polymer diodes enables long-term reliable radio-frequency energy harvesting on plastic","authors":"Yongwoo Lee, Boseok Kang, Sungjune Jung, Jimin Kwon","doi":"10.1038/s41528-024-00326-y","DOIUrl":"10.1038/s41528-024-00326-y","url":null,"abstract":"Due to their inherent flexibility, solution-processable conjugated polymers are increasingly being considered for the cost-effective production of thin-film semiconductor devices used in Internet of Everything (IoE) applications. With considerable improvements in charge carrier mobilities, the final challenge impeding the commercialization of conjugated polymers may be improving their environmental and electrical stabilities. Recent studies have improved the stability of computing devices (i.e., transistors) by eliminating interface traps and water molecules within conjugated polymers. However, the stability issue of Schottky diodes, which play a crucial role in configuring thin-film IoE devices used in wireless communication and energy harvesting, has been largely overlooked. This study reveals that aluminum, which is commonly used as a cathode metal in polymer Schottky diodes, creates a nonstoichiometric effect when deposited on conjugated polymers, thereby leading to the formation of charge traps over time, which reduces the rectification ratio of the Schottky diodes and induces a significant bias stress effect during operation. To address this issue, we introduce a zinc-oxide sacrificial interlayer between the conjugated polymer and cathode. This interlayer effectively eliminates the penetrated Al metal or ionized Al-induced nonstoichiometric effect without reducing the charge injection efficiency, achieving exceptional environmental and operational stability. The printed polymer Schottky diodes demonstrate consistent rectifying operation at 13.56 MHz for several months with negligible changes in electrical characteristics.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-11"},"PeriodicalIF":12.3,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00326-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141730416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-area magnetic skin for multi-point and multi-scale tactile sensing with super-resolution","authors":"Hao Hu, Chengqian Zhang, Xinyi Lai, Huangzhe Dai, Chengfeng Pan, Haonan Sun, Daofan Tang, Zhezai Hu, Jianzhong Fu, Tiefeng Li, Peng Zhao","doi":"10.1038/s41528-024-00325-z","DOIUrl":"10.1038/s41528-024-00325-z","url":null,"abstract":"The advancements in tactile sensor technology have found wide-ranging applications in robotic fields, resulting in remarkable achievements in object manipulation and overall human-machine interactions. However, the widespread availability of high-resolution tactile skins remains limited, due to the challenges of incorporating large-sized, robust sensing units and increased wiring complexity. One approach to achieve high-resolution and robust tactile skins is to integrate a limited number of sensor units (taxels) into a flexible surface material and leverage signal processing techniques to achieve super-resolution sensing. Here, we present a magnetic skin consisting of multi-direction magnetized flexible films and a contactless Hall sensor array. The key features of the proposed sensor include the specific magnetization arrangement, K-Nearest Neighbors (KNN) clustering algorithm and convolutional neural network (CNN) model for signal processing. Using only an array of 4*4 taxels, our magnetic skin is capable of achieving super-resolution perception over an area of 48400 mm2, with an average localization error of 1.2 mm. By employing neural network algorithms to decouple the multi-dimensional signals, the skin can achieve multi-point and multi-scale perception. We also demonstrate the promising potentials of the proposed sensor in intelligent control, by simultaneously controlling two vehicles with trajectory mapping on the magnetic skin.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-12"},"PeriodicalIF":12.3,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00325-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141730423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient shuttle for a widespread neural probe with minimal perturbation","authors":"Yeonwook Roh, Hyeongseok Kim, Eun-A Kim, Kyungbin Ji, Minji Kang, Dohyeon Gong, Sunghoon Im, Insic Hong, Jieun Park, Soo Jung Park, Yiseul Bae, Jae-Il Park, Je-Sung Koh, Seungyong Han, Eun Jeong Lee, Daeshik Kang","doi":"10.1038/s41528-024-00328-w","DOIUrl":"10.1038/s41528-024-00328-w","url":null,"abstract":"Bioelectronic implants in the deep brain provide the opportunity to monitor deep brain activity with potential applications in disease diagnostics and treatment. However, mechanical mismatch between a probe and brain tissue can cause surgical trauma in the brain and limit chronic probe-based monitoring, leading to performance degradation. Here, we report a transient shuttle-based probe consisting of a PVA and a mesh-type probe. A rigid shuttle based on PVA implants an ultrathin mesh probe in the target deep brain without a tangle, while creating both a sharp edge for facile penetration into the brain and an anti-friction layer between the probe and brain tissue through dissolving its surface. The capability to shuttle dissolved materials can exclude the retracted process of the shuttle in the brain. Complete dissolution of the shuttle provides a dramatic decrease (~1078-fold) in the stiffness of the probe, which can therefore chronically monitor a wide area of the brain. These results indicate the ability to use a simplistic design for implantation of wide and deep brain probes while preventing unnecessary damage to the brain and probe degradation during long-term use.","PeriodicalId":48528,"journal":{"name":"npj Flexible Electronics","volume":" ","pages":"1-11"},"PeriodicalIF":12.3,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41528-024-00328-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141608168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}