Smart Fibers for Self‑Powered Electronic Skins

Smart fibers are considered as promising materials for the fabrication of wearable electronic skins owing to their features such as superior flexibility,light weight,high specific area,and ease of modification.Besides,piezoelectric or triboelectric electronic skins can respond to mechanical stimulation and directly convert the mechanical energy into electrical power for self-use,thereby providing an attractive method for tactile sensing and motion perception.The incorporation of sensing capabilities into smart fibers could be a powerful approach to the development of self-powered electronic skins.Herein,we review several aspects of the recent advancements in the development of self-powered electronic skins constructed with smart fibers.The summarized aspects include functional material selection,structural design,pressure sensing mechanism,and proof-to-concept demonstration to practical application.In particular,various fabrication strategies and a wide range of practical applications have been systematically introduced.Finally,a critical assessment of the challenges and promising perspectives for the development of fiber-based electronic skins has been presented.

Field Sensing Characteristic Research of Carbon Fiber Smart Material

In order to research the field sensing characteristic of the carbon fiber smart material, the Tikhonov regularization principle and the modified Newton-Raphson(MNR) algorithm were adopted to solve the inverse problem of the electrical resistance tomography(ERT). An ERT system of carbon fiber smart material was developed. Field sensing characteristic was researched with the experiment. The experimental results show that the specific resistance distribution of carbon fiber smart material is highly consistent with the distribution of structural strain. High resistance zone responds to high strain area, and the specific resistance distribution of carbon fiber smart material reflects the distribution of sample strain in covering area. Monitoring by carbon fiber smart material on complicated strain status in sample field domain is realized through theoretical and experimental study.

Smart Behavior of Carbon Fiber Reinforced Cement-based Composite

The electrical characteristics of cement-based material can be remarkably improved by the addition of short carbon fibers. Carbon fiber reinforced cement composite (CFRC) is an intrinsically smart material that can sense not only the stress and strain, but also the temperature. In this paper, variations of electrical resistivity with external applied load, and relation of thermoelectric force and temperature were investigated. Test results indicated that the electrical signal is related to the increase in the material volume resistivity during crack generation or propagation and the decrease in the resistivity during crack closure. Moreover, it was found that the fiber addition increased the linearity and reversibility of the Seebeck effect in the cement-based materials. The change of electrical characteristics reflects large amount of information of inner damage and temperature differential of composite, which can be used for stress-strain or thermal self-monitoring by embedding it in the concrete structures.

Characteristics of Smart Concrete with Fiber Optical Bragg Grating Sensor

Based on the advantages of the fiber Bragg grating sensing technology,this paper presents a principle of a novel smart concrete with fiber optical Bragg grating sensor,analyses the theory and characteristics,illustrates the key technology and method to make the fiber Bragg grating sensor for the smart concrete,and proves the feasibility with experiments.The results indicate that the smart concrete with fiber Bragg grating sensors is feasible in the structure monitoring and damage diagnosing in the long run.

The Smart Behavior of Cement-based Composite Containing Carbon Fibers under Three-point-bending Load

The influences of the fiber volume fraction on the electrical conductivity and the fraction change of electrical resistance under three-point-bending test were discussed.It is found that the relationship beween the electrical conductivity of composites and the fiber volume fraction can be explained by the percolation theory and the change of electrical resistance of specimens reflects to the process of loading.The sensitivity and the response of the change of electrical resistance to the load for specimens with different fiber volume fractions are quite different.which provide an important guide for the manufacture of conductive and intrinsically smart carbon fiber composite.

Carbon-Coated-Nylon-Fiber-Reinforced Cement Composites as an Intrinsically Smart Concrete for Damage Assessment during Dynamic Loading

Concrete containing short carbon-coated-nylon fibers (0.4-2.0 vol. pct) exhibited quasi-ductile response by developing a large damage zone prior to fracture localization. In the damage zone, the material was microcracked but continued to local strain-harden. The carbon-coated-nylon-fiber-reinforced concrete composites (NFRC) were found to be an intrinsically smart concrete that could sense elastic and inelastic deformation, as well as fracture. The fibers served to bridge the cracks and the carbon coating gave the conduction path. The signal provided came from the change in electrical resistance, which was reversible for elastic deformation and irreversible for inelastic deformation and fracture. The resistance decrease was due to the reduction of surface touch resistance between fiber and matrix and the crack closure. The resistance irreversible increase resulted from the crack opening and breakage of the carbon coating on nylon fiber.

埋入式光纤模式功率调制传感原理及实验研究——航天smart结构

对 Smart材料 /结构中的光纤传感原理进行了探讨 ,并进行了实验研究。这种新研制的传感器工作原理是基于模式功率调制。远场光强将反映结构内的变形场 ,亦即光纤受到外界加载或扰动后所产生的变形。最后提出了应用多模光纤在编织复合材料 Smart结构中进行远场光强测量的方案 ,建立了实验装置 ,给出了实验结果并进行了讨论。

埋入式光纤传感原理及实验研究——航天Smart结构

对Ｓｍａｒｔ材料／结构中的光纤传感原理进行了探讨，并进行了实验研究。首先介绍了Ｓｍａｒｔ结构中常见的埋入式光纤传感器的特点及其工作原理，然后提出了应用多模光纤在编织复合材料Ｓｍａｒｔ结构中进行应变场测量的方案，建立了实验装置，给出了实验结果并进行了讨论。

玻纤企业绩效评价新思路——基于G-SMART原则的低碳经济增加值指标

我国已成为玻纤生产第一产能大国,针对玻纤生产企业,可以从管理层面建立起低碳绩效评价指标,通过衡量低碳绩效反应企业低碳生产水平,从而实现低碳发展。基于传统的绩效评价SMART原则利用经济增加值评价方法,考虑企业碳和污染物排放水平,创新性地提出运用G-SMART原则并结合专家访谈和问卷调查构建低碳经济增加值指标,通过因子分析提取综合指标并得到各综合指标权重来计算各项指标低碳经济增加值,评价企业的低碳绩效。

Three dimensional photovoltaic fibers for wearable energy harvesting and conversion

As the development of smart electronics, self-powered sources have been attracting increasing attention.This review summarizes research progress of photovoltaic fibers and their integrated power sources with multi-stage energy conversion. Recent development of three dimensional photovoltaic fibers is glanced with special attention to structure design and materials of typical photovoltaic types（inorganic, organic,dye/quantum dot sensitized and perovskite solar cells）. The application of carbon materials in fiber energy is focused as it is a hot topic recently. The hybrid energy systems based on fiber solar cells and fiber supercapacitors, fiber batteries and fiber nanogenerators are summarized together with hybrid energy textiles. This review provides a macroscopic view of novel energy fibers and will attract research interest in flexible/wearable fiber electronics and energy textiles.

Resistance Responses of Carbon Fiber Cement to Cycled Compressive Stresses

The stress-resistance relationship of carbon fiber cement was studied.Attention has been paid to explore the improvement of the stress-resistance sensitivity under cycled stress restriction.The prismy carbon fiber cement sensors were pre-fabricated.The factors such as contents of carbon fibers.silica fume,dispersant and the w/c were taken into account.The electrical resistance variations with the dynamic and static loads were simulated using a strain-controlled test machine.The test results show that there is an optimal fiber content,with which the compression-sensitivity achieves a high level.The addition of silica fume can improve the sensitivity.Under the optimal test conditions,the measured resistances can greatly correspond with the changes of the load.

Performance Improvement Method of CFRP with Embedded Optical Fiber

Optical fiber-based sensors are usually applied in structural health monitoring(SHM)as part of smart materials.The weak interface between the optical fiber and the host material will reduce the mechanical performance of the smart materials.Normally,the principal parts of the optical fibers are inorganic,while the matrix of host material is organic.These two kinds of materials can not be combined.Micro-fracture can be found in smart materials.Two methods for improving the interface are proposed.Firstly,the influence of the interface size on the strength is studied.Secondly,interfacial treatment before embedding the optical fiber into the composite is analyzed.Compressive tests of composite laminated specimens are conducted to evaluate the proposed methods.The specimens are produced from T300Carbon/epoxy prepreg,with different treated optical fiber embedded inside.The experimental results indicate that smaller interface size and proper treatment will strengthen the whole structure.

基于CiteSpace的智能纺织服装产品研究进展

为揭示智能纺织服装的研究现状、热点和趋势,以CNKI数据库和WOS数据库中2012—2022年的相关文献为研究对象,采用CiteSpace可视化分析软件绘制知识图谱,分析智能纺织服装产品在国家、机构、作者方面的分布现状及合作情况,对研究热点和前沿趋势进行梳理。结果表明,2012—2022年,CNKI数据库发文量稳步上升,WOS数据库发文量快速增长且中国学者发文量较多;CNKI数据库研究合作强度较低且以东华大学和江南大学为主体;WOS数据库合作关系密切,研究集中度和合作强度大;CNKI数据库研究方向更注重应用和设计模式,WOS数据库则更注重电子元件制造和智能纤维与面料的开发;健康检测、变色肌理、仿生设计、生物材料、可穿戴应变等是目前智能纺织服装领域的前沿热点,电子元件制造、智能纤维及面料智能化研究是未来智能纺织服装领域研究的热点及趋势。

Modification of Interfacial Performance of Fiber Bragg Grating Embedded in the Composite Materials

The interfacial performance of the Fiber Bragg grating（FGB） embedded in the composite was studied and the influence of interface modification on the final profile of the spectra of the FBG sensor was examined. A type of polyamine（Pentaethylenehexamine, PEHA） was proposed to modify the coating of PI on FBG, and the interfacial performance was evaluated by a pull-out test. Sharp improvements of the interfacial shear strength（77%） were obtained by 40 min treatment of PEHA. Compared with untreated specimen, FGB spectra of treated specimen in the tensile tests show improved linearity within the test regime, which proves that the enhanced interface is beneficial for the sensing performance.

SIZE EFFECT AND LOADING RATE DEPENDENCE OF THE PRESSURE-SENSITIVITY OF CARBON FIBER REINFORCED CONCRETE(CFRC)

Carbon fiber reinforced concrete(CFRC) was found to be anintrinsically smart material. An experi- mental study is presented toexamine the influence of size effect and loading rate on thepressure-sensitivity of CFRC during the elastic regime. The resultsshow that the sensitiv- ity increases with the size of specimenincreasing and load- ing rate makes no influence on it. The former isbecause the deformation of higher specimen is larger than lower oneunder the same compressive stress. The behind is because thedeformation of specimen is the same under the same com- pressivestress although the loading rate is different. Therefore, the smartbeharvior of CFRC also reflects the Deformation of material undercompressive stress.

基于智能跑道光栅阵列传感器的机型辨识方法

针对当前机型辨识方法易受环境影响的不足,提出了一种新的基于智能跑道光栅阵列传感器的机型辨识方法。利用光栅阵列横向布置光缆采集飞机滑跑通过时的分布式振动响应,通过分析多测区时程脉冲响应特征,确定主辅起落架通过光缆的时差。通过光栅阵列纵向布置光缆感知飞机的滑行轨迹,采用多项式拟合确定飞机滑行速度。基于飞机主辅起落架的测试值与理论值的匹配关系对飞机型号进行辨识,利用某机场试飞及开航2个月内的航班信息进行方法检验。结果显示,提出的机型辨识方法识别准确率可达98.44%,可以对B757、B738、A320和A321机型进行有效辨识。

A refined finite element method for bending analysis of laminated plates integrated with piezoelectric fiber-reinforced composite actuators

This research presents a finite element formulation based on four-variable refined plate theory for bending analysis of cross-ply and angle-ply laminated composite plates integrated with a piezoelectric fiber-reinforced composite actuator under electromechanical loading. The four-variable refined plate theory is a simple and efficient higher-order shear deformation theory, which predicts parabolic variation of transverse shear stresses across the plate thickness and satisfies zero traction conditions on the plate free surfaces. The weak form of governing equations is derived using the principle of minimum potential energy, and a 4-node non-conforming rectangular plate element with 8 degrees of freedom per node is introduced for discretizing the domain. Several benchmark problems are solved by the developed MATLAB code and the obtained results are compared with those from exact and other numerical solutions, showing good agreement.

智能纤维及智能针织产品的发展与应用

智能纤维及智能针织产品是一项蓬勃发展的领域,随着先进技术及材料的发展,智能针织产品为人们的生活提供了诸多的便利。探讨当前智能纤维材料及智能针织产品的最新进展和趋势。首先,介绍了智能纤维的特点、分类和生产方法等,包括智能变色纤维、形状记忆纤维、智能调温纤维、光导纤维、电子智能纤维以及智能凝胶纤维。然后,分析了智能针织产品的生产技术以及应用领域。最后,探讨了智能纤维和智能针织产品存在的问题和面临的挑战,并且给出了未来智能针织产品的发展方向。通过深入研究和创新,智能纤维及智能针织产品将为我们的生活带来更多可能性,促进智能生产与生活的实现。

基于GOOSE反馈机制的智能变电站过程层网络备用方法

智能变电站过程层光纤网络一旦发生故障,会使二次系统功能失效,故障修复效率低,可靠性降低。为此,提出一种基于GOOSE反馈机制的智能变电站过程层网络备用方法。文章根据二次系统对过程层网络的传输要求,对间隔抖动、丢帧率和光功率等指标建立相应的危害程度量化模型;建立了备用光纤光口单指标和综合指标启动判据;利用GOOSE反馈机制实现对主光纤光口的备用。仿真表明,所提方法可快速完成故障光纤光口的备用切换,提高了过程层网络的可靠性。

一维结构可穿戴柔性传感器研究进展

随着智能可穿戴技术的发展,人们对智能化、多功能、易携带的可穿戴设备需求日益增长,可穿戴柔性传感器受到广泛关注并逐渐成为柔性电子领域的研究热点。一维结构柔性传感器具备优异适形性、高集成度和性能稳定等优势,有助于开发高性能、可连续生产、多场景应用的可穿戴柔性电子产品。文章分析了用于一维结构穿戴柔性传感器的导电敏感材料和柔性基底材料,对一维结构穿戴柔性传感器的制备工艺进行划分,从表面涂层、纤维制备以及结构变化方面总结了各种一维结构穿戴柔性传感器的设计和应用。文章讨论了一维结构柔性传感器当前研究中需要突破的工作,对其在可穿戴应用领域的发展前景提出展望,为相关可穿戴柔性器件的研究提供理论价值和工程参考意义。