共查询到20条相似文献，搜索用时 15 毫秒
1.
为获得优异力学性能的复合材料,选用石墨烯作为增强体.本文采用粉末冶金方法,经高能球磨法、冷压、烧结、热压和热挤压制备了AZ31镁合金及石墨烯(GNPs)增强AZ31镁基复合材料棒状试样,通过光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射(XRD)和室温拉伸、压缩表征了该材料的组织和力学性能.结果表明:制备的复合材料及基体中生成了Mg_(17)Al_(12)和MgO,加入GNPs后复合材料的屈服强度与维氏硬度都优于基体材料;加入GNPs质量分数为0.5%和1.0%的GNPs复合材料分别比基体屈服强度增加13.2%和14.2%(258和259 MPa),显微维氏硬度分别增加11.4%和14.3%(78和80 HV),主要的强化机制为载荷转移强化、奥罗万强化、热错配强化,但材料的拉伸延伸率分别降低到3.9%和4.3%,比基体分别降低了38%和32%,材料的致密度分别为99.6%、98.5%、97.8%,随着GNPs的增加,致密度降低;GNPs的加入未改变材料的断裂方式,材料的断裂方式均主要为脆性断裂;GNPs的添加使复合材料的基面{0002}织构弱化,从而降低材料的屈服不对称性. 相似文献
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Flexible wearable sensors are expected to be the future generation of personal health monitoring devices with large‐area, multimodal, multipoint sensing, and complicated data analysis. However, multimaterial interfacial coalescence and mechanical matching critically challenge the advancement of flexible devices and multifunction integration. Graphene, with characteristic carbon sheet 2D material, is endowed with good transparency, stability, superior electron mobility, heat conductivity, excellent flexibility, and mechanical performance. A summary of the progresses of flexible graphene‐based sensors in terms of material processing, sensor configuration, and property is presented. Various assembly structures could perform different electrical behaviors with unitary graphene material. The diversity of graphene‐based temperature, humidity, pressure, strain, and integrated multifunctional sensors developed in recent years is detailed. Benefitting from the commendable flexible mechanical performance and high durability, flexible graphene‐based sensors promote practical applications in body temperature monitoring, voice recognition, pulse‐beating, motion, and respiration detection. Finally, future research following the development trends and challenges of integrated graphene‐based sensors to develop their potential in human health monitoring and human–machine interfaces are discussed. 相似文献
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Aqsa Javaid;Muhammad Hamza Zulfiqar;Muhammad Shoaib Saleem;Muhammad Atif Khan;Muhammad Zubair;Yehia Massoud;Muhammad Qasim Mehmood; 《Advanced Engineering Materials》2024,26(10):2301138
Tremendous development in intelligent wearable gadgets creates opportunities for flexible strain sensors. Comfortable and safe flexible strain sensors have high demand in wearable applications and therefore the textile-based strain sensors are desired. Achieving attributes like easy fabrication, cost-effectiveness, high sensitivity, good stability, and portability is still a challenge to overcome. In this regard, textile-based flexible strain sensors, one on jeans fabric and other on cotton fabric, are presented. A conventional interdigitated electrode structure is adopted and sensors are prepared by facile and economical fabrication process. Both sensors own high sensitivity factors, i.e., gauge factor >200 and stability of ≈10 000 cycles. The anticipated works show a linear response R2 = 0.99, low hysteresis <5%, and minimum resolution <7°. The intended sensors are implemented for real-time application, i.e., the physiotherapy of the knee and neck. The jeans-fabric-based sensor is used for knee therapy and the cotton for neck. The daily therapy sessions are recorded and examined. The sensors respond well to the applied strain during therapy sessions, proving to be an outstanding choice for integration into biomedical wearable devices for therapeutic purposes. The proposed sensors can also be auspicious candidates for targeting many other wearable applications. 相似文献
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Chunya Wang Kailun Xia Huimin Wang Xiaoping Liang Zhe Yin Yingying Zhang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(9)
Flexible and wearable electronics are attracting wide attention due to their potential applications in wearable human health monitoring and care systems. Carbon materials have combined superiorities such as good electrical conductivity, intrinsic and structural flexibility, light weight, high chemical and thermal stability, ease of chemical functionalization, as well as potential mass production, enabling them to be promising candidate materials for flexible and wearable electronics. Consequently, great efforts are devoted to the controlled fabrication of carbon materials with rationally designed structures for applications in next‐generation electronics. Herein, the latest advances in the rational design and controlled fabrication of carbon materials toward applications in flexible and wearable electronics are reviewed. Various carbon materials (carbon nanotubes, graphene, natural‐biomaterial‐derived carbon, etc.) with controlled micro/nanostructures and designed macroscopic morphologies for high‐performance flexible electronics are introduced. The fabrication strategies, working mechanism, performance, and applications of carbon‐based flexible devices are reviewed and discussed, including strain/pressure sensors, temperature/humidity sensors, electrochemical sensors, flexible conductive electrodes/wires, and flexible power devices. Furthermore, the integration of multiple devices toward multifunctional wearable systems is briefly reviewed. Finally, the existing challenges and future opportunities in this field are summarized. 相似文献
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《Advanced Materials Technologies》2017,2(12)
This paper reports on a simple and versatile method for patterning and transferring graphene‐based nanomaterials onto various types of tape to realize flexible microscale sensors. The method involves drop‐casting a graphene film on a prepatterned polydimethylsiloxane (PDMS) surface containing negative features by graphene suspensions, applying Scotch tape to remove the excess graphene from the nonpatterned areas of the PDMS surface, and then transferring the patterned graphene from the inside of the negative features at the PDMS surface onto a target tape. The feature size of transferred graphene patterns on the final tape is as small as a few micrometers. This method is easy to implement, but does not require the use of expensive equipment, except for needing a PDMS substrate containing negative features. This method has a high versatility in producing micropatterns of graphene‐based nanomaterials on different types of adhesive tape. For the purpose of application demonstration, flexible mechanical sensors and sensor arrays, smart gloves, and plant leaf sensors on tapes to realize real‐time monitoring of important signals indicating human motion and plant water transport behavior have been developed. This technology will open a new route for low‐cost, scalable, and roll‐to‐roll production of graphene‐based sensors on tape. 相似文献
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Xueyang Ge;Zhengcan Sun;YongXin Guo;Chenbo Gong;Runyi Han;Jingrui Feng;Zichen Qi;Jing Gao;Dong Wen;Fei Bian;Zhaopeng Xu; 《Advanced Materials Technologies》2024,9(10):2302083
Wearable health monitoring sensors, when employed to monitor pulse and sweat volume in real-time during human physical activity, serve as an effective preventative measure against abnormal health conditions, such as elevated heart rate or excessive dehydration. Herein, a dual-functional sensor based on a sandwich structure composed of polyvinylidene fluoride hexafluoropropylene / conductive carbon black perforated film (named PCp film) and corncob sponge is designed to monitor pulse and sweat volume. The PCp film prepared by the breath figure method serves as a piezoresistive sensor with high sensitivity (0.06 kPa−1), a fast response time (0.9 ms), and high reusability for pulse monitoring. Furthermore, the PCp film has excellent water permeability (27.3 L m−2 h−1); thus, the sweat permeating through the PCp film can be absorbed by the corncob sponge. The sandwich-structured capacitive sensor is also highly sensitive (6.021 pF nL−1) to the absorbed sweat and is highly reusable. In addition, the dual-functional sensor is successfully integrated into a sports bracelet system to display real-time pulse and sweat-volume data of the wearer. This approach provides a dependable foundation for the advancement of multifunctional sensors in the field of sports monitoring. 相似文献
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Weijie Liu Nishuang Liu Yang Yue Jiangyu Rao Feng Cheng Jun Su Zhitian Liu Yihua Gao 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(15)
Piezoresistive sensor is a promising pressure sensor due to its attractive advantages including uncomplicated signal collection, simple manufacture, economical and practical characteristics. Here, a flexible and highly sensitive pressure sensor based on wrinkled graphene film (WGF)/innerconnected polyvinyl alcohol (PVA) nanowires/interdigital electrodes is fabricated. Due to the synergistic effect between WGF and innerconnected PVA nanowires, the as‐prepared pressure sensor realizes a high sensitivity of 28.34 kPa?1. In addition, the device is able to discern lightweight rice about 22.4 mg (≈2.24 Pa) and shows excellent durability and reliability after 6000 repeated loading and unloading cycles. What is more, the device can detect subtle pulse beat and monitor various human movement behaviors in real‐time. 相似文献
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Zhiming Lin Zhiyi Wu Binbin Zhang Yi‐Cheng Wang Hengyu Guo Guanlin Liu Chaoyu Chen Yuliang Chen Jin Yang Zhong Lin Wang 《Advanced Materials Technologies》2019,4(2)
Accurately monitoring human gait is critical for health evaluation and/or early diagnosis, especially for elder and injured people's healthcare. The presence of gait abnormalities could be important predictors of the risk of developing diseases. Herein, a triboelectric nanogenerator (TENG)‐based smart insole for real‐time gait monitoring is reported. Due to the novel air‐pressure‐driven structural design, the elastic TENG‐based sensors exhibit compelling features including simple fabrication, fast response time, high durability, and excellent mechanical robustness. The TENG‐based sensors can be easily integrated into the conventional insole so that it can convert the mechanical triggering/impact into electrical output. By analyzing such electrical signals, the smart insole could accurately monitor and distinguish various gait patterns in real time, including jump, step, walk, and run. The smart insole could also be used to monitor the abnormality of gait for rehabilitation assessment. In addition, the smart insole can play another important role in healthcare applications, for example, serving as a fall‐down alert system for elder people or patients. This work not only paves a new way for real‐time and long‐term gait monitoring, but also presents a new perspective for the practical applications of remote clinical biomotion analysis. 相似文献
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Haomin Wang Shuo Li Haojie Lu Mengjia Zhu Huarun Liang Xunen Wu Yingying Zhang 《Small Methods》2023,7(2):2201340
Traditional public health systems suffer from incomprehensive, delayed, and inefficient medical services. Convenient and comprehensive health monitoring has been highly sought after recently. Flexible and wearable devices are attracting wide attention due to their potential applications in wearable human health monitoring and care systems. Using carbon materials with overall superiorities can facilitate the development of wearable and flexible devices with various functions and excellent performance, which can comprehensively and real-time monitor human health status and prevent diseases. Herein, the latest advances in the rational design and controlled fabrication of carbon materials for applications in health-related flexible and wearable electronics are reviewed. The fabrication strategies, working mechanism, performance, and applications in health monitoring of carbon-based flexible devices, including electromechanical sensors, temperature/humidity sensors, chemical sensors, and flexible conductive wires/electrodes, are reviewed. Furthermore, integrating multiple carbon-based devices into multifunctional wearable systems is discussed. Finally, the existing challenges and future opportunities in this field are also proposed. 相似文献
12.
Hua Xu Ming Kun Zhang Yi Fei Lu Jia Jia Li Si Jia Ge Zhong Ze Gu 《Advanced Materials Technologies》2020,5(2)
Wearable strain sensors with high sensitivity and broad sensing ranges to detect both subtle and large human motion are highly desirable in health monitoring systems. Here, a novel, dual‐mode strain sensor based on the reduced graphene oxide (rGO)/polydimethlsiloxane (PDMS) film adhered to micropatterning elastomer colloidal crystal film is proposed to realize these goals. The rGO/PDMS film is designed for detecting subtle human motion via its resistance change, while the colloidal crystal film is used for detecting large human motion via its simple colorimetric changes or reflection peak shifts and simultaneously as a microstructured substrate for graphene film to improve their sensitivity. Investigation of their detection ability displays that the colloidal crystal film exhibits a wide sensing range up to 68.2% strain and the rGO/PDMS film demonstrates a high gauge factor value of 4.78 within 30% strain with rapid response time and excellent reversibility. Such superior performance endows the dual‐mode sensor for detecting various large human joint movements and subtle human physiological motions. This research provides new insights into the design and fabrication of high‐performance strain sensor for full‐range human motions' detection and the proposed sensor has great potential for application in human motion recognition and healthcare monitoring. 相似文献
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Fengxiao Niu Zhen Qin Lizhen Min Biao Zhao Yuhuan Lv Xiaohui Fang Kai Pan 《Advanced Materials Technologies》2021,6(11):2100394
3D aerogel-based piezoresistive sensors have attracted tremendous attention due to their high sensitivity and excellent mechanical properties. Here, a novel piezoresistive sensor with ultrahigh linear sensitivity is tactfully designed and prepared based on nanofiber-reinforced MXene–reduced graphene oxide aerogel. The presence of MXene endows the piezoresistive sensor with high conductivity. Besides, the nanofibers can act as a scaffold to improve the compression resilience of the aerogel significantly by penetrating the entire aerogel network. Furthermore, due to the synergy effect among the multiple components, the prepared piezoresistive sensor exhibits outstanding performance, including high linear sensitivity (331 kPa−1 from 0 to 500 Pa, 126 kPa−1 from 500 Pa to 7.5 kPa), fast response time (load 71 ms, recovery 15 ms), and low detection limit (1.25 Pa). More importantly, it can maintain stable signal output even after 17 000 compression cycles. Furthermore, the prepared sensor can efficiently detect breathing, heartbeat, and vocalization of the human body in real time. Based on these advantages, the prepared sensor is expected to show significant potentials in future flexible wearable electronic devices. 相似文献
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Qi Zhang Yu Lu Wang Yun Xia Peng Fei Zhang Timothy V. Kirk Xiao Dong Chen 《Advanced Materials Technologies》2019,4(10)
Wearable sensors promise advances in monitoring for athletes and patients, and offer the possibility of convenient longitudinal data collection without compromising lifestyle or comfort. To fully realize these possibilities, devices should be easily integrated into the clothing, accessories, and medical products that best suit consumers. An effective capacitive strain sensor whose components consist solely of fibers with a textile thread‐like morphology, i.e., that requires no solid polymer matrix that complicates integration, and can be woven directly into the fabric of clothing, bandages, and other products is presented. It is produced by twisting two core‐spun yarns into a fine double‐ply yarn. The core‐spun yarns are fabricated by wrapping silver‐coated nylon fibers with cotton fibers, and fixing them with polyurethane. Excellent capacitive linearity is displayed, with high dielectric stability over 10 000 cycles of endurance testing. Other detection properties are in line with existing sensors, though with lower ultimate strain and elastic limit. Textile integration is demonstrated via incorporation with kneepads and gloves without compromise of comfort or range of motion. All materials are compatible with medical sterilization methods. Additional versatility is illustrated by weaving the core‐spun yarn into pressure sensor arrays, which can be blended into wearable fabrics. 相似文献
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Flexible piezoresistive pressure sensors have been attracting wide attention for applications in health monitoring and human‐machine interfaces because of their simple device structure and easy‐readout signals. For practical applications, flexible pressure sensors with both high sensitivity and wide linearity range are highly desirable. Herein, a simple and low‐cost method for the fabrication of a flexible piezoresistive pressure sensor with a hierarchical structure over large areas is presented. The piezoresistive pressure sensor consists of arrays of microscale papillae with nanoscale roughness produced by replicating the lotus leaf's surface and spray‐coating of graphene ink. Finite element analysis (FEA) shows that the hierarchical structure governs the deformation behavior and pressure distribution at the contact interface, leading to a quick and steady increase in contact area with loads. As a result, the piezoresistive pressure sensor demonstrates a high sensitivity of 1.2 kPa−1 and a wide linearity range from 0 to 25 kPa. The flexible pressure sensor is applied for sensitive monitoring of small vibrations, including wrist pulse and acoustic waves. Moreover, a piezoresistive pressure sensor array is fabricated for mapping the spatial distribution of pressure. These results highlight the potential applications of the flexible piezoresistive pressure sensor for health monitoring and electronic skin. 相似文献
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This study aims to develop self-powered smart shoes that can monitor the changes in the bodyweight of a user. A tension-type energy harvester and strain sensor are fabricated using polyvinylidene fluoride-based ribbons and nanopowder containing piezoresistive ribbons, respectively. Two different conducting nanopowders (carbon black and multi-walled carbon nanotubes) are used as stretchable sensors, and the most appropriate mixing ratio of the nanopowders is determined. The energy harvesting performance of the tension-type ribbon harvesters is experimentally investigated based on the combination patterns of ribbons and gait patterns, and a method is introduced to apply the harvesting ribbon to shoes. Tension-type ribbon sensors that detect bodyweight are installed in an acrylic insole with four rectangular holes. The connecting method between the sensors, which guarantees the stability and high sensitivity of the sensor signals, is investigated. Finally, electronic circuits are designed for energy harvesting, data communication, and switching power sources. These designed circuits are implemented in smart shoes. 相似文献
20.
Shantonu Biswas Yitian Shao Taku Hachisu Tung Nguyen‐Dang Yon Visell 《Advanced Materials Technologies》2020,5(8)
Recent developments in stretchable electronics hold promise to advance wearable technologies for health monitoring. Emerging techniques allow soft materials to serve as substrates and packaging for electronics, enabling devices to comply with and conform to the body, unlike conventional rigid electronics. However, few stretchable electronic devices achieve the high integration densities that are possible using conventional substrates, such as printed rigid or flexible circuit boards. Here, a new manufacturing method is presented for wearable soft health monitoring devices with high integration densities. It is shown how to fabricate soft electronics on rigid carrier substrates using microfabrication techniques in tandem with strain relief features. Together, these make it possible to integrate a large variety of surface mount components in complex stretchable circuits on thin polymer substrates. The method is largely compatible with existing industrial manufacturing processes. The promise of these methods is demonstrated by realizing skin‐interfaced devices for multimodal physiological data capture via multiwavelength optoelectronic sensor arrays comprised of light emitting diodes and phototransistors. The devices provide high signal‐to‐noise ratio measurements of peripheral hemodynamics, illustrating the promise of soft electronics for wearable health monitoring applications. 相似文献