基于MXene的电化学传感研究进展EI北大核心CSCD

MXene是一种早期过渡金属碳化物、氮化物或碳氮化物组成的二维(2D)层状材料。由于MXene具有独特的层状形态、高电导率、高比表面积、优异的亲水性和良好的热稳定性等特性,在物理、化学和纳米技术领域具有广阔的应用前景,可应用于催化、储能和传感器等多种科学领域。本文主要综述基于MXene的电化学传感器的研究进展,介绍电化学传感器的原理、构成,传感界面修饰和MXene制备方法,着重讨论MXene在电化学酶传感器、电化学非酶传感器、电化学免疫传感器、电化学适体传感器和电化学分子印迹传感器方面的研究进展,指出MXene电化学传感领域工业化和商业化利用不足、新种类MXene开发的挑战,对其在各类分析物检测、更多潜在领域的应用进行展望。     

磁性传感材料与器件研究进展

磁性材料是一种既古老又新颖的功能材料,磁性材料本身具有诸多特殊性质,正是基于此类特性,磁性材料可以完成外界物理量与磁信号之间的相互转换,由此制成各种类型的磁性传感器.随着传感器向着智能化、微型化、多功能化、高灵敏度、低功耗、高可靠性发展,新型磁性传感器种类也迅速增加,应用场景愈加广阔.然而,由于人类对磁信号的探测及处理远不如电学信号成熟,磁性传感器的应用仍有诸多问题尚未解决.材料的研究者们更关注新磁学现象,而能成功应用于传感器的磁性材料除了其特有的磁敏特性外,还应根据其具体应用场景提高它的其他物理性能,而传感器的研究者们在解决传感器微型化、高灵敏度等问题时并不会优先从材料角度考虑问题,导致某一类磁性材料从发现到其成熟应用于传感器所经历的周期过长,而很多已发现的磁性材料并未找到合适的应用场景.从材料角度而言,目前在传感器领域应用最多的是磁电阻材料,其广泛应用于位移传感器、角速度传感器、硬盘磁头、非接触电流测量等领域.其他研究较成熟的磁性材料如软磁材料、磁致伸缩材料、磁电复合材料、磁流体材料等在传感器领域也有一定的应用,如力学传感器、生物传感器、光学传感器等.为了使磁性传感器有广泛的应用,磁性材料及磁性传感器的研究者们应从应用角度出发,根据不同应用场景,提出更为全面具体的材料性能要求,以此为目标,对现有的磁性材料进行改性处理,或研发新型磁性材料,加快磁性材料及磁性传感器领域的发展.本文综述了多种磁性材料(包括磁电阻材料、高磁导率软磁材料、巨磁阻抗材料、磁致伸缩材料、磁光材料、磁电复合材料、磁流体材料等)在磁场探测、光学传感、力学传感、生物传感、电流传感等方面的应用以及研究进展,并从应用的角度出发,展望了未来磁性材料及磁性传感器的发展前景,以期为新型磁性传感器的制造及应用提供参考.     

基于PSO算法的MFF模型的参数辨识与优化

基于磁链理论和Monte-Carlo法,建立了磁流体薄膜(MFF)传感模型和MFF透射模型,分析了磁流体透射特性。采用粒子群算法对MFF透射模型进行了参数辨识,分析了群体数目、迭代次数、惯性权重、加速度因子等参数选值对算法运行结果的影响,并选取了最佳参数组合。搭建了MFF电流传感器实验平台,运用MFF透射模型对MFF电流传感器进行了仿真预测,分析了MFF厚度和粒子浓度对MFF透射性的影响,实验及仿真结果表明该模型预测误差在2.3%以内,该MFF电流传感器的测量灵敏度达到12 μW/A。     

细菌视紫红质在生物传感器中的应用进展

生物传感器是生物敏感材料、理化换能器与电信号放大装置等多学科交叉的综合集成技术装置.典型的生物传感器以特异性感知的生物活性材料作为敏感元件,结合基于微电子器件的物理化学换能器和调理电路,实现生物敏感信息的电信号转换及放大.换能器的灵敏度、抗干扰能力等因素直接影响生物传感器的性能.从嗜盐菌中提取的细菌视紫红质是一种具有良好光敏特性的生物材料,可直接将光信号转化成电信号,从而实现将敏感元件和换能器合二为一的功能,已广泛应用于多种生物传感器中.细菌视紫红质的感光灵敏度和稳定性适用于开发具有颜色灵敏度的光传感器,最早的应用方向是人工视网膜;其光敏感和换能一体化特性可实现使用单个传感元件进行光学运动检测的功能,应用可扩展到运动传感领域.除了在视觉传感领域的应用,细菌视紫红质在病原体检测、水体pH检测、细胞膜电位检测等领域均表现出良好的灵敏性、稳定性和特异性.其不仅在生物传感领域具有应用价值,而且为半导体传感方法的研究提供了新途径.本文在简述细菌视紫红质的质子泵和光电响应特性等基本功能的基础上,阐述了细菌视紫红质构建生物传感器的应用进展,分析了不同传感器的特点,以期为细菌视紫红质的机理及其应用研究提供参考.     

激发态分子内质子转移:一种新型的传感机制及其在荧光传感器中的应用

荧光传感器具有灵敏度高、专一性强、样品处理简易及操作过程方便、响应速度快、可用于体内和体外成像研究等优点,颇受人们的青睐。在新型荧光传感器的设计中,传感器识别单元与信号报告单元之间的传感机制一直受到人们的广泛关注。随着超分子科学的发展,一些新型的传感机制被应用于传感器的设计中。其中,基于激发态分子内质子转移(ESIPT)机理的荧光传感器通常具有发光强、斯托克斯位移较大、光稳定性好等优异特性,表现出良好的传感性能。综述了ESIPT这种新型的荧光传感机制的研究进展,包括此传感机制的基本原理,其在荧光传感器设计中的应用,并展望了该领域的发展趋势。     

磁流体动力学角速率传感技术发展现状

针对飞行器内微幅、宽频微角振动测量的困难,美国ATA公司研制了基于磁流体动力学(MHD)角速率传感器。与光纤陀螺等器件相比,该传感器具有测量精度高、频谱范围宽、结构简单等特点,在航空航天、地基武器、地震监测等领域具有潜在应用。从MHD角速率传感技术的应用背景出发,通过系统描述高精度、低频等五类MHD角速率传感技术的基本原理、结构组成、关键参数等内容,梳理MHD角速率传感器的发展脉络,并探索性研究MHD角速率传感技术未来发展可能所需突破的关键技术。     

磁流体的光学特性及其在光电信息传感领域中的应用

详细介绍了磁流体的光学性质,包括磁流体的热透镜效应、磁光效应.磁流体折射率的可控性以及磁致分色效应.由于磁流体的光学性质具有可调谐性,这为磁流体在新型光子器件与光纤传感器的设计和研究提供了新原理.新材料.论述了应用磁流体设计的多路复用器、光开关、光纤调制器、可调谐磁流体光栅与可调谐滤波器,以及基于磁流体的光纤电流传感器原理和结构.     

正交异性压电传感器在结构健康诊断中的应用

通过正交异性压电（Orthotropic Piezoelectric Composite Materials,简称OPCM）传感器与普通压电（PZT）传感器的传感特性比较,证明了OPCM传感器对同平面内相互正交的AE信号具有不同的响应特性.基于OPCM传感器的这一特性,将其作为结构健康诊断系统中的声发射传感器,可减少结构侧面等边界反射的影响,有效保留损伤和/或缺陷的有用信息.结合Gabor小波时频分析方法和透射波法,能增强声发射技术探测结构损伤的能力,并减少了测试仪器的通道数量,为实用的结构健康诊断提出了新的思路并建立了相关的理论模型.     

多孔有机聚合物在传感领域中的研究进展

多孔有机聚合物(POPs)是由轻质元素(C、H、O、N、B等)通过较强的共价键相互连接而形成的一类二维或三维多孔网状结构的多孔材料。其由于具有较大的比表面积，丰富的孔隙结构，极高的孔隙率，物理化学稳定性，以及易于功能化等特性，近年来人们在传感器应用领域中进行了较为深入的研发。总结了近年来各种POPs在气体传感、金属离子传感、爆炸物传感、药物传感、生物传感等领域的研究进展，并探讨了未来的技术发展方向与前途。     

PVDF薄膜压电传感特性及其在工程结构监测应用研究进展

PVDF压电薄膜因其体积小、质量轻、稳定性高、传感灵敏度高、制作成本低等优点而被广泛应用于工程结构监测体系中。总结了PVDF压电薄膜基本特点、工作原理及静/动态传感特性,并指出其用作应变传感器在工程结构或构件局部监测中具有的优势;分析了以PVDF压电薄膜作为传感元件在工程实际监测中应用实例,最后对其在结构监测方面应用前景做了相关展望。     

微传感器最新发展

近年来，微传感器受到国际传感技术界的广泛关注，本文介绍十多个微传感器，包括三轴加速度计，单，双轴加速度计片，表面微机械陀螺（角速度传感器），微惯性导航系统，微磁通门传感器，磁阻传感器，纳米皮拉尼压力传感器，微科氏质量流量计，毫米波图像传感器，GPS手表（1cm^3)，二氧化碳传感器和微/超微角位移传感器，文事简要介绍它们的基本结构。敏感机理，特点等，从中可以看出微传感器已成为传感技术中有重要应用前景的组成部分。     

The resolving power of magneto-modulation sensors with an amorphous ferromagnetic core

The resolving power of magnetic-field magneto-modulation sensors with an amorphous ferromagnetic core with respect to energy, magnetic flux and induction in the low-frequency range is considered. It is shown that the high energy sensitivity and resolution with respect to the magnetic flux does not always correspond to the lowest sensitivity threshold of the magnetic-induction sensor.     

Optimization of magnetic calorimeters

The properties and performance of magnetic calorimeters based on Au containing a few hundred ppm of Er can be fully described by equilibrium thermodynamics. As a consequence, the magnitude of the change of magnetization of the sensor, resulting from the absorption of a particle, can be calculated with confidence. The magnetization change depends upon a number of parameters such as the external magnetic field, the temperature and the concentration of the Er ions. This theoretical understanding of the calorimeter also allows us to calculate the flux signal detected by a SQUID and how that signal depends on the detector geometry and other relevant parameters. To date we have measured only cylindrically shaped sensors, which are located directly in a circular SQUID loop. However, a sensor having the shape of a thin strip, possibly in form of a meander pattern, enclosed by a loop of the same geometry, has the potential of providing enhanced flux coupling to the SQUID. We discuss the relation of sensor geometry to other parameters such as the dimensions and heat capacity of an attached particle absorber. The values of the adjustable parameters that optimize the performance of a magnetic calorimeter are investigated under a number of different experimental constraints.     

Quantification of multiple bioagents with wireless, remote-query magnetoelastic microsensors

This paper presents a micromagnetoelastic sensor array for simultaneously monitoring multiple biological agents. Magnetoelastic sensors, made of low-cost amorphous ferromagnetic ribbons, are analogous and complementary to piezoelectric acoustic wave sensors, which track parameters of interest via changes in resonance behavior. Magnetoelastic sensors are excited with magnetic ac fields, and, in turn, they generate magnetic fluxes that can be detected with a sensing coil from a distance. As a result, these sensors are highly attractive, not only due to their small size and low cost, but also because of their passive and wireless nature. Magnetoelastic sensors have been applied for monitoring pressure, temperature, liquid density, and viscosity, fluid How velocity and direction, and with chemical/biological responsive coatings that change mass or elasticity, various biological and chemical agents. In this paper, we report the fabrication and application of a six-sensor array for simultaneous measurement of Escherichia coli O157:H7, staphylococcal enterotoxin B, and ricin. In addition, the sensor array also monitors temperature and pH so the measurements are independent from these two parameters.     

Use of membranes in sensor technology

In this article, Editorial Board member Dr Peter Ball discusses how microporous membranes can be used in a variety of applications in the construction of sensors. This includes their uses as a surface to which molecules involved in the detection function of the sensor are coupled, as a reading surface in the sensor for measurement of a signal and as a barrier to passage of undesired components of the fluid being analysed. The physical and chemical properties of microporous membranes make them well-suited to this role. This article discusses these properties and gives examples of how membranes may be utilised in sensors.     

Modeling of piezoelectric sensor fidelity

Ideal piezoelectric sensors should measure the response of a structure in a nonintrusive manner. The size of the sensor should be relatively small and its properties well matched to the structure. The voltage response of a piezoelectric sensor embedded in a fluid loaded plate structure is modeled using a hybrid finite element approach. The structure is excited by an obliquely incident acoustic signal. Finite element modeling is used for the structure and the fluid surrounding the transducer region, and a plane wave representation is invoked to match the displacement field on a mathematical boundary. On this boundary, continuity of field derivatives is enforced by using a penalty factor and to further achieve transparency at the mathematical boundary, drilling degrees of freedom (d.o.f.) are introduced in the finite element representation. Another novel feature in the FEM is the use of solid elements for the acoustic fluid augmented by an irrotational constraint to render the fluid inviscid. Numerical results are presented for the sensor response of an immersed plate structure. The voltage excited in the piezoelectric sensor is studied as a function of sensor and host material properties, size of sensor, and poling direction of the sensor with respect to the structure. The effect of multiple sensors on one another is also studied. It is found that piezoelectric sensors can be nonintrusive and sensitive to the characteristics of the structure     

磁流变弹性体压缩模式动态力学性能测试

磁流变弹性体是一种新型的磁流变材料,已被成功地应用于变刚度器件设计中。为了评价磁流变弹性体材料性能,迫切需要建立一套磁流变弹性体性能测试系统。利用电磁振动台的线性扫频功能,采用激光位移传感器同步获取测试系统在不同磁感应强度下测试系统的激励与响应信号,通过系统的运动力学模型和相关理论计算,实现压缩模式下的磁流变弹性体刚度与阻尼性能的测试。该测试系统的建立为研制高性能的磁流变弹性体提供了动态压缩模式下的评价手段。     

Bead Capture on Magnetic Sensors in a Microfluidic System

The accumulation of magnetic beads by gravitational sedimentation and magnetic capture on a planar Hall-effect sensor integrated in a microfluidic channel is studied systematically as a function of the bead concentration, the fluid flow rate, and the sensor bias current. It is demonstrated that the sedimentation flux is proportional to the bead concentration and has a power law relation to the fluid flow rate. The mechanisms for the bead accumulation are investigated and it is found that gravitational sedimentation dominates the bead accumulation, whereas the stability of the sedimented beads against the fluid flow is defined by the localized magnetic fields from the sensor.      

Output Properties of Zero-Speed Sensors Using FeCoV Wire and NiFe/CoFe Multilayer Thin Film

Output properties of magnetic sensors generating pulse voltages are described. The sensors principally consisted of double magnetic layers with different coercive forces. Both of thin-film-based material and wire-based material were used for the double layers. When the magnetization of one of the layers was switched by an external magnetic field, a pulse voltage was induced in a pickup-coil wound around the materials. The magnetic sensor using a twisted FeCoV wire, the conventional material for the Wiegand effect, had the disadvantage of the asymmetric output voltage generated by the alternative magnetic field. It was found that a magnetic wire, whose ends were slightly etched, exhibited symmetric output voltage. The sensor element consisting of a patterned NiFe/CoFe multilayer thin film was also studied. Constant output voltage was obtained from this thin-film sensor using an excitation magnetic field at frequencies down to 0.1 Hz.