Fabrication Techniques and Sensing Mechanisms of Textile‑Based Strain Sensors:From Spatial 1D and 2D Perspectives

The intelligent textile sensors based on fiber(1D)and fabric(2D)are the ideal candidates for wearable devices.Their flexible weaving and unique structure endow them with flexibility,lightweight,good air permeability,and feasible integration with garments.In view of the spring-up of novel textile-based strain sensors,the novel materials and fabrication approaches were elaborated from spatial perspectives,i.e.,1D fibers/yarn and 2D fabric.The intrinsic sensing mechanism is the primary fac-tor affecting sensor sensitivity,and the variation trend of the sensing signal is closely related to it.Although existing studies have involved various sensing mechanisms,there is still lacking systematic classification and discussion.Hence,the sensing mechanisms of textile-based sensors were elaborated from spatial perspectives.Considering that strain sensors were mostly based on resistance variation,the sensing mechanisms of resistive textile-based strain sensors were mainly focused,mainly including fiber deformation,tunneling effect,crack propagation,fabric deformation,electrical contact and bridge connec-tion.Meanwhile,the corresponding resistance prediction models,usually used as important data fitting methodology,were also comprehensively discussed,which can reproduce the resistance trend and provide guidance for the sensor performance.Finally,the multifunctionality of textile-based strain sensors was summarized,namely multi-mode signal detection,visual interaction,energy collection,thermal management and medical treatment were discussed.It was expected to provide research insights into the multifunctional integration of textile sensors.

Large‑scale Fabrication of Snake‑skin‑inspired Protective Composite Textiles

Inspired by the overlapping structure of snake scales,a reinforced scale-like knitted fabric(R-SLKF)was created in this work.To achieve this,short carbon fibers in an epoxy resin(ER)matrix were incorporated into the scales of an SLKF.The resulting textile is a highly stable protective composite that is flexible,warm,and thermally insulated.In addition,supe-rior stab-resistance is ensured through rigid protective blocks in the R-SLKF,making up a hard overlapping scale region,besides satisfactory flexibility via soft twisted ultra-high-molecular-weight polyethylene yarn-based textiles.The R-SLKF achieves high stab resistance(peak load of approximately 600 N for a single scale thickness of 2 mm),good flexibility(~290 mN cm),and breathability(100 MPa,423 mm/s),coupled with good warmth retention and thermal insulation prop-erties(0.28℃/s),which are superior to previously reported protective composite textiles.From the results,the combination of desirable individual protection,excellent wearability and comfort enables human beings to survive in extremely danger-ous environments.Finite element simulations provided valuable insights into the factors influencing the stab resistance of R-SLKF and elucidated the underlying anti-puncture mechanism in accordance with the experimental findings.This study presents a novel strategy for the facile industrial fabrication of flexible and lightweight protective composite textiles,which is expected to enhance the structure and material design for future innovations and provide advantages for personal protec-tive equipment in various industrial fields.

2D multifunctional devices:from material preparation to device fabrication and neuromorphic applications

Neuromorphic computing systems,which mimic the operation of neurons and synapses in the human brain,are seen as an appealing next-generation computing method due to their strong and efficient computing abilities.Two-dimensional (2D) materials with dangling bond-free surfaces and atomic-level thicknesses have emerged as promising candidates for neuromorphic computing hardware.As a result,2D neuromorphic devices may provide an ideal platform for developing multifunctional neuromorphic applications.Here,we review the recent neuromorphic devices based on 2D material and their multifunctional applications.The synthesis and next micro–nano fabrication methods of 2D materials and their heterostructures are first introduced.The recent advances of neuromorphic 2D devices are discussed in detail using different operating principles.More importantly,we present a review of emerging multifunctional neuromorphic applications,including neuromorphic visual,auditory,tactile,and nociceptive systems based on 2D devices.In the end,we discuss the problems and methods for 2D neuromorphic device developments in the future.This paper will give insights into designing 2D neuromorphic devices and applying them to the future neuromorphic systems.

Novel fabrication techniques for ultra-thin silicon based flexible electronics

Flexible electronics offer a multitude of advantages,such as flexibility,lightweight property,portability,and high durability.These unique properties allow for seamless applications to curved and soft surfaces,leading to extensive utilization across a wide range of fields in consumer electronics.These applications,for example,span integrated circuits,solar cells,batteries,wearable devices,bio-implants,soft robotics,and biomimetic applications.Recently,flexible electronic devices have been developed using a variety of materials such as organic,carbon-based,and inorganic semiconducting materials.Silicon(Si)owing to its mature fabrication process,excellent electrical,optical,thermal properties,and cost efficiency,remains a compelling material choice for flexible electronics.Consequently,the research on ultra-thin Si in the context of flexible electronics is studied rigorously nowadays.The thinning of Si is crucially important for flexible electronics as it reduces its bending stiffness and the resultant bending strain,thereby enhancing flexibility while preserving its exceptional properties.This review provides a comprehensive overview of the recent efforts in the fabrication techniques for forming ultra-thin Si using top-down and bottom-up approaches and explores their utilization in flexible electronics and their applications.

A Twisting Fabrication Process for Wearable Electronic Devices

The advancement of integrated circuits has made it easier to reduce the size of increasingly potent wearable electronic devices.However,it is still difficult to seamlessly integrate electronic systems enabling unrestricted human behavior into wearable gadgets.The procedure of creating fiber devices by twisting fiber electrodes and incorporating them into textile systems is exhibited in recent work.These textile systems are highly resilient and flexible,which makes them ideal for various wearable applications,i.e.,thread lithium-ion batteries(TLIBs),multi-ply sensing threads(MSTs),and thread electroluminescent devices(TELDs).

Recent advances in fabrication and functions of neuromorphic system based on organic field effect transistor

The development of various artificial electronics and machines would explosively increase the amount of information and data,which need to be processed via in-situ remediation.Bioinspired synapse devices can store and process signals in a parallel way,thus improving fault tolerance and decreasing the power consumption of artificial systems.The organic field effect transistor(OFET)is a promising component for bioinspired neuromorphic systems because it is suitable for large-scale integrated circuits and flexible devices.In this review,the organic semiconductor materials,structures and fabrication,and different artificial sensory perception systems functions based on neuromorphic OFET devices are summarized.Subsequently,a summary and challenges of neuromorphic OFET devices are provided.This review presents a detailed introduction to the recent progress of neuromorphic OFET devices from semiconductor materials to perception systems,which would serve as a reference for the development of neuromorphic systems in future bioinspired electronics.

Near-zero-adhesion-enabled intact wafer-scale resist-transfer printing for high-fidelity nanofabrication on arbitrary substrates

There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates,so as to meet the fast-growing need for broad applications in nanoelectronics,nanophotonics,and fexible optoelectronics.Existing direct-lithography methods are difficult to use on fexible,nonplanar,and biocompatible surfaces.Therefore,this fabrication is usually accomplished by nanotransfer printing.However,large-scale integration of multiscale nanostructures with unconventional substrates remains challenging because fabrication yields and quality are often limited by the resolution,uniformity,adhesivity,and integrity of the nanostructures formed by direct transfer.Here,we proposed a resist-based transfer strategy enabled by near-zero adhesion,which was achieved by molecular modification to attain a critical surface energy interval.This approach enabled the intact transfer of wafer-scale,ultrathin-resist nanofilms onto arbitrary substrates with mitigated cracking and wrinkling,thereby facilitating the in situ fabrication of nanostructures for functional devices.Applying this approach,fabrication of three-dimensional-stacked multilayer structures with enhanced functionalities,nanoplasmonic structures with~10 nm resolution,and MoS2-based devices with excellent performance was demonstrated on specific substrates.These results collectively demonstrated the high stability,reliability,and throughput of our strategy for optical and electronic device applications.

Design and Fabrication of Flexible Thermoelectric String-Based Fabrics

Flexible thermoelectric(TE)materials that convert heat into electricity have been widely used in wearable electronics and other flexible devices.In this work,inorganic TE pillars were combined with thermoplastic polyurethane(TPU)to assemble a flexible string-shaped TE generator(TEG)for the fabrication of the thermoelectric fabric(TEF).Moreover,finite element analysis(FEA)was used to optimize the dimensions of the TE string and evaluate its performance.The FEA results showed that the inter-pillar spacing significantly affected the temperature difference,the output voltage and the internal resistance.A maximum power density of 3.43μW/cm^(2)(temperate gradientΔT=10.5 K)was achieved by the TE string with a diameter of 3.5 mm and an inter-pillar spacing of 2 mm.However,under the experimental condition,the achievable power density of the fabricated three-dimensional(3D)TEF was limited to 29%of the simulation result because of the inclination of the TE string within the fabric concerning heat plate contact and copper wire-TE pillar connections.The actual TE string also demonstrated high flexibility and stable mechanical properties after 450 bending cycles.Thus,the study would provide a foundation for future research in developing more efficient TEFs to offer a comfortable and conformable option for wearable energy harvesting applications.

Two-step Synthesis of TiC_(0.7)N_(0.3)@WC-MoC_2 Core-shell Microspheres and Fabrication of TiC_(0.7)N_(0.3)@WC-MoC_2-based Cermets by SPS

The precursor with TiC0.7N0.3@WO3-MO3 microspheres were prepared by a novel method from the WO3-MoO3 sol dipping. Subsequently, TiC0.7N0.3@WC-MoC2 core-shell structural microspheres were successfully obtained by carburizing the precursor at 900 °C in a flowing mixture of CH4 （20 ml·min-1） and H2 （200 ml·min-1） for 2 h. Then TiC0.7N0.3@WC-MoC2-15Co cermets were prepared utilizing the core-shell powders by spark plasma sintering （SPS）. Powders of the precursors with TiC0.7N0.3@WO3-MO3 microspheres, TiC0.7N0.3@WC-MoC2 microspheres and TiC0.7N0.3@WC-MoC2-15Co cermets were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and X-ray diffraction （XRD）. The obtained TiC0.7N0.3@WC-MoC2 microspheres have a dense WC-MoC2 coatings shell. The thickness of the shell could be easily controlled by adjusting the number of sol dipping cycles. It was found that the TiC0.7N0.3@WC-MoC2 microspheres were more beneficial to fabricate the ＂core-rim＂ structures by SPS.

Smart Cellulose‑Based Janus Fabrics with Switchable Liquid Transportation for Personal Moisture and Thermal Management

The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.

Identification of Stability Domains for Flow Parameters in Fused Filament Fabrication Using Acoustic Emission

In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow state is affected by multiple parameters,with temperature and volumetric flow rate(VFR)being the most critical.The study explores the stable extrusion of flow with a highly sensitive acoustic emission(AE)sensor so that AE signals generated by the friction in the annular region can reflect the flow state more effectively.Nevertheless,the large volume and broad frequency range of the data present processing challenges.This study proposes a method that initially selects short impact signals and then uses the Fast Kurtogram(FK)to identify the frequency with the highest kurtosis for signal filtration.The results indicate that this approach significantly enhances processing speed and improves feature extraction capabilities.By correlating AE characteristics under various parameters with the quality of extruded raster beads,AE can monitor the real-time state of material flow.This study offers a concise and efficient method for monitoring the state of raster beads and demonstrates the potential of online monitoring of the flow states.

FABRICATION OF Bi NANOWIRE ARRAY BY ELECTRODEPOSITION TECHNOLOGY

In the fabrication of Bi nanowire array thermoelectric materials,electrodeposition technology has been used to deposit bismuth into the nanopores of anodic alumina porous films.The experiments show that the temperature significantly affects the electrodepositing process,and the simple form of Bi 3+ in the solutions is helpful to the deposition of metal Bi.The pulse plating technique is necessary for the electrodeposition because of the diffusive difficulty of Bi 3+ into the nanopores of the films.The XRD analysis indicates that Bi nanowire arrays have been manufactured by this technology.

一种面向联盟链Hyperledger Fabric的并发冲突事务优化方法

随着区块链技术应用的普及,联盟链Hyperledger Fabric(简称Fabric)已成为知名区块链开源平台,并得到广泛关注.然而Fabric仍受困于并发事务间冲突问题,冲突发生时会引发大量无效交易上链,导致吞吐量下降,阻碍其发展.对于该问题,现有面向块内冲突的方案缺乏高效的冲突检测和避免方法,同时现有研究往往忽略区块间冲突对吞吐量的不利影响.提出了一种Fabric的优化方案Fabric-HT(fabric with high throughput),从区块内和区块间2方面入手,有效降低事务间并发冲突和提高系统吞吐量.针对区块内事务冲突,提出了一种事务调度机制,根据块内冲突事务集定义了一种高效数据结构——依赖关系链,识别具有“危险结构”的事务并提前中止,合理调度事务和消除冲突;针对区块间事务冲突,将冲突事务检测提前至排序节点完成,建立以“推送-匹配”为核心的冲突事务早期避免机制.在多场景下开展大量实验,结果表明Fabric-HT在吞吐量、事务中止率、事务平均执行时间、无效事务空间占用率等方面均优于对比方案.Fabric-HT吞吐量最高可达Fabric的9.51倍,是最新优化方案FabricSharp的1.18倍;空间利用率上相比FabricSharp提升了14%.此外,Fabric-HT也表现出较好的鲁棒性和抗攻击能力.

Assembly fabrication of linkers on glass surface and their effect on DNA synthesis and hybridization

Linkers were assembled on a glass surface based on the hydrolysis and condensation of 3-glycidoxy￣propyltrimethoxysilane (GPS). After the assembly of GPS, four approaches were tried to open the ending epoxide group of GPS or to further elongate the linkers. The effect of these approaches on DNA in situ synthesis and hybridization was investigated. For the spacing of the synthesis initiation sites, the wettability of the support and the length of the linking group that attaches the initiation site to the surface have direct influences on the yield of coupling reactions and the subsequent hybridization events. X-ray photoelectron spectroscopy (XPS) and mean contact angles of deionized water of the above slides were measured to assess the linker's characteristics in each procedure. It was proved that the glass slides were successfully modified and became excellent supports for the oligonucleotides synthesis. In addition, it proved best for the in situ oligonucleotides synthesis that a glass slide was in turn treated with ethylenediamine, glutaradehyde, ethanolamine and sodium borohydride solution at ambient temperature after silanized with GPS.

Fabrication of micro-honeycomb ceramics by cloth fabric pore-forming

Micro-honeycomb ceramics were successfully fabricated through brush-coating with cloth fabric as pore-forming agent. The influence of pore-forming agent and slurry’s moisture content on the micro-honeycomb ceramics was investigated. The results indicated that micro-honeycomb ceramics made from pore-forming agent cloth fabric with fibre diameter of 100 μm and slurry with 45% （mass fraction） moisture content have the porosity of 65% （volume fraction）, bending strength of 24.3 MPa, pore size of about 100 μm, cell wall thickness of about 50 μm and porosity of 1131 pore/cm2. It was suggested that the pore size and the porosity could be adjusted using the pore-forming agent and moisture content of the slurry respectively.

基于Fabric的海量交易数据上链预处理机制

Hyperledger Fabric是一种国内外广泛使用的联盟链框架,在基于Fabric技术的一些业务中具有协同组织众多、交易操作频繁、事务冲突增加等特点。Fabric采用的多版本并发控制技术能够在一定程度上解决部分交易冲突,提升系统并发性,但其机制不完善,会出现部分交易数据无法正常上链存储的问题。为了实现海量交易数据完整、高效、可信的上链存储,提出一种基于Fabric预言机的数据上链预处理机制。设计海量数据冲突预处理(MCPP)方法,通过检测、监听、延时提交、事务加锁、重排序缓存等方式实现主键冲突交易数据的完整上链。引入数据传输保障措施,在传输过程中利用非对称加密技术防止恶意节点伪造认证信息,确保交易数据链外处理前后的一致性。通过理论分析和实验结果表明,该机制可有效解决联盟链平台中海量交易数据上链时的并发冲突问题,当交易数据规模达到1 000和10 000时,MCPP的时效性比LMLS提高了38%和21.4%,且成功率接近100%,具有高效性和安全性,同时在无并发冲突情况下不影响Fabric系统性能。

Fabrication,magnetostriction properties and applications of Tb-Dy-Fe alloys:a review

As an excellent giant-magnetostrictive material, Tb-Dy-Fe alloys(based on Tb0.27-0.30Dy0.73-0.70Fe1.9-2Laves compound) can be applied in many engineering fields, such as sonar transducer systems, sensors, and micro-actuators. However, the cost of the rare earth elements Tb and Dy is too high to be widely applied for the materials. Nowadays, there are two different ways to substitute for these alloying elements. One is to partially replace Tb or Dy by cheaper rare earth elements, such as Pr, Nd, Sm and Ho; and the other is to use non-rare earth elements, such as Co, Al, Mn, Si, Ce, B, Be and C, to substitute Fe to form single MgCu_2-type Laves phase and a certain amount of Re-rich phase, which can reduce the brittleness and improve the corrosion resistance of the alloy. This paper systemically introduces the development, the fabrication methods and the corresponding preferred growth directions of Tb-Dy-Fe alloys. In addition, the effects of alloying elements and heat treatment on magnetostrictive and mechanical properties of Tb-Dy-Fe alloys are also reviewed, respectively. Finally, some possible applications of Tb-Dy-Fe alloys are presented.

基于CP-ABE算法的Fabric隐私保护模型

传统区块链系统缺少对区块数据的隐私保护。结合CP-ABE(基于属性加密的密文策略)算法和IPFS(星际文件系统),提出一种可以对Fabric区块链实现访问控制的隐私保护模型CP-PPM。CP-PPM的数据所有者可以灵活设置访问控制策略。仿真结果表明,与现有Fabric区块链系统相比,CP-PPM模型支持细粒度的访问控制,具有更强的隐私保护效果;CP-ABE算法可以安全初始化,对数据的加解密效率更高,同时增强了区块链系统的存储性能。

Technical Issues for the Fabrication of a CN-HCCB-TBM Based on RAFM Steel CLF-1

Reduced activation ferritic/martensitic steel （RAFM） is recognized as the primary candidate structural material for ITER＇s test blanket module （TBM）. To provide a material and property database for the design and fabrication of the Chinese helium cooled ceramic breeding TBM （CN HCCB TBM）, a type of RAFM steel named CLF-1 was developed and chaxacter^zed at the Southwestern Institute of Physics （SWIP）, China. In this paper, the R＆D status of CLF-1 steel and the technical issues in using CLF-1 steel to manufacture CN HCCB TBM were reviewed, including the steel manufacture and different welding technologies. Several kinds of property data have been obtained for its application to the design of the ITER TBM.

Fabrication and Thermal Properties of a New Heat Storage Concrete Material

A new type heat storage concrete material used in solar thermal power was fabricated by using aluminates cement to be the gelatinizer, and using high heat capacity materials, such as basalt and bauxite, as aggregate, and adding high heat conductivity graphite and high efficient water reducing agent. The experimental results show the addition of graphite can improve the thermal conductivity of the concrete, the value of thermal conductivity is about 2.34 W/mK which means the obtained concrete storage material has excellent thermal properties, and it is expected to be a good heat storage material used in solar power.