精密压阻弹性体及力敏触觉传感器阵列

空气热氧化用多元醇溶剂热方法得到的金属钌纳米颗粒,可以得到纳米氧化钌颗粒,将其与金属钌纳米粉体混合,使其具有适当的聚集特性,将混合粉体与硅橡胶复合,呈现具有良好的压阻重复性和压阻敏感性,测量不同尺寸电极间的压阻行为,表明此种导电硅橡胶在毫米尺寸以上呈现一定的标度不变性,表明材料在一定尺寸范围内满足微型化要求,适用于集成的压阻弹性体应力测量阵列,我们制备了测量面载荷分布的阵列电极,设计了用于动态触觉传感测量的电路和支持软件,结果表明,针对压阻材料电阻/载荷敏感特性,通过每个压阻单元微秒级的信号获取和数据处理,可以实现毫米尺度的静态或动态载荷三维成像,该传感阵列的可重复和定量特性使其基本满足实用的人体工学器件要求。     

炭黑/硅橡胶导电复合材料力敏元件温度响应试验研究

利用炭黑/硅橡胶导电复合材料制作了大变形力敏传感元件,对其温度荷载下的电阻响应进行了试验研究,并根据其导电机理对温敏特性进行了深入分析.试验发现制作的大变形力敏传感元件具有正温度系数特性,电阻随温度的升高而增大;温度稳定时,具有电阻弛豫现象.硅橡胶基体随温度变化体积发生变化是造成复合材料温度敏感性的主要原因;同时,温度变化也会影响电子跃迁能力,进而影响到复合材料温度响应.橡胶基体的粘弹性以及试样具有一定厚度的尺寸效应是导致其温度响应滞后性的主要原因.     

新型智能机器人触觉传感服装阵列标定的研究

为使智能机器人在汽车冲撞试验中获得准确的触觉信息,研发了一种基于导电橡胶压阻特性的新型触觉传感服装阵列.针对该传感阵列设计了静态标定试验装置,在常温下(25℃)研究了不同型号的导电橡胶( N05,N10,N15)的压阻行为特性,选出压敏性最佳的N10作为触觉传感服装的敏感元件;在此基础上提出了标定方案,标定结果表明:高...     

炭黑/硅橡胶导电敏感复合材料可重复性试验研究

利用溶剂法工艺制备了炭黑/硅橡胶导电复合材料,对其进行了拉伸及压缩敏感试验,研究其可重复性。拉伸试验结果表明,各配方试样电阻-拉伸应变曲线均具有较好的可重复性(最大应变达到24%左右);C4与C6试样的可重复性略差于C8~C18试样,这主要是由于炭黑含量小于6%时,复合材料内部导电网络不太稳定造成的。压缩试验结果表明,复合材料的压阻敏感性也具有一定的可重复性(最大压力达到15 MPa左右)。总体看来,炭黑/硅橡胶复合材料的拉伸及压缩敏感性在较大拉伸应变及压应力范围内都具有较好的可重复性及线性度,满足开发传感器的基本性能要求。     

压阻式微型压力传感器微型 化限制因素的研究

本文初步探讨了对压阻式传感器的微型化起限制作用的多种因素:根据(100)晶面硅片各向异性腐蚀的特点,得出了器件芯片最小尺寸与硅片厚度的关系;根据方膜和矩形膜上应力分布曲线,得出了在一定的图形位置偏差下压力灵敏度与硅膜几何尺寸的关系曲线;讨论了硅片厚度均匀性与力敏电阻尺寸对器件总尺寸的限制作用,比较了全桥结构和横向压阻X型结构对器件几何尺寸的要求。最后介绍了两种实用的微型压力传感器设计与其主要技术参数。     

炭黑/纳米Al2O3填充柔性压敏导电硅胶体系的研究

基于柔性触觉传感器中用到的压敏导电硅橡胶,研究添加纳米Al2O3对导电硅橡胶电特性的影响.从理论上研究纳米Al2O3改性的微观和宏观机理,并通过实验对添加不同量纳米Al2O3的压敏导电硅橡胶导电性、室温下的导电稳定性、压阻特性进行比较分析.实验结果表明:在炭黑浓度恒定的压敏导电硅橡胶中适量添加纳米Al2O3,可有效提高复合材料的导电性,稳定性,增大复合材料的压力敏感范围.     

用于机器人皮肤的柔性多功能触觉传感器设计与实验

为实现智能机器人皮肤对三维力和温度的检测,设计并制作了一种柔性多功能触觉传感器.基于碳黑-硅橡胶显著的压阻效应设计了四电极对称结构的三维力传感器,基于碳纤维-PDMS(聚二甲硅氧烷)显著的温度敏感效应设计了叉指电极结构的温度传感器,分析了检测三维力和温度的工作原理.针对两种导电复合材料存在的力学/温度敏感特性交叉干扰问...     

大变形力敏传感元件温度响应试验研究

利用炭黑/硅橡胶导电复合材料制作了大变形力敏传感元件,对其温度荷载下的电阻响应进行了试验研究,并根据其导电机理对温敏特性进行了深入分析。试验发现制作的大变形力敏传感元件具有正温度系数特性,电阻随温度的升高而增大;温度稳定时,具有电阻弛豫现象。硅橡胶基体随温度变化体积发生变化是造成复合材料温度敏感性的主要原因;同时,温度变化也会影响电子跃迁能力,进而影响到复合材料温度响应。橡胶基体的粘弹性以及试样具有一定厚度的尺寸效应是导致其温度响应滞后性的主要原因。     

新型有机/无机触压传感器材料的制备及性能的研究

以硅橡胶做为基体,通过掺杂导电碳黑和Al2O3纳米粉制成了富有弹性、导电性好、稳定性优良的复合材料,找出了材料导电性突变时碳黑掺杂的体积分数为38%;并对碳黑体积分率不同时的复合材料进行了压阻特性的测量,发现随着材料中碳黑体积分率的增加,材料的弹性变差;进一步利用超声波分散技术将Al2O3纳米粉分散到材料当中,发现纳米粉的加入改善了材料的导电性能和弹性性能.文章最后计算了材料的压阻灵敏度,发现所制备材料的压阻灵敏度可达1.5 Ω/Pa.     

导电橡胶触觉传感器阵列的标定实验研究

导电橡胶传感器是智能机器人服装的核心机件;标定出导电橡胶传感器的压阻特性是实现智能机器人触觉传感服装的核心内容之一;实验中,将导电橡胶安装在柔性阵列电极板里制作成触觉传感器阵列服装。对该传感器提出多种测量方法,确立其标定模型;给出数据建模的一般步骤。指出导电橡胶传感器设计的改进方向与部分方法。     

Vortices around Janus droplets under externally applied electrical field

In this study, the Janus droplet is an oil droplet covered with aluminum oxide nanoparticles on one side of the droplet surface under applied DC electrical field. The vortices around Janus droplets fixed on a horizontal surface were studied in this paper. A numerical model was set up to simulate the vortices around the Janus droplet in electric field. The simulation results illustrate that the electric field determines the strength of the vortices around a fixed Janus droplet, and the surface coverage of the positively charged nanoparticles on a Janus droplet affects the size and location of the vortices. The numerically predicted results were further validated experimentally by visualizing the vortices around Janus droplets in an externally applied DC electric field. Furthermore, as the Janus droplets are generated in electric field, the surface coverage by the nanoparticles depends on the strength of the electric field; therefore, the effect of the electric field on the nanoparticle covered surface area of a Janus droplet and the vortices was analyzed.     

Synthesis of hollow, magnetic Fe/Ga-based oxide nanospheres using a bubble templating method in a microfluidic system

This paper describes a new approach to synthesize hollow nanospheres in a microfluidic system using air bubbles as templates. A new microfluidic system which integrates a micro-mixer, a micro-condenser channel, microvalves, a micro-heater, and a micro-temperature sensor, to form an automatic micro-reactor, is used to generate air bubbles that assist in the synthesis of hollow Fe/Ga-based oxide nanospheres. Experimental data show that Fe/Ga-based oxide nanoparticles with a diameter of 157 ± 26 nm can be successfully synthesized. The formation mechanism is that the seed nanoparticles are attaching themselves onto the bubbles to form a solid shell. The magnetic properties of the hollow Fe/Ga-based oxide nanospheres are also measured. This may be a promising platform to synthesize hollow nanoparticles for drug delivery applications.     

Self-assembling of micro-patterned titanium oxide films for gas sensors

Metal oxide nanoparticles are interesting building blocks for realizing films for a number of applications that include bio- and -chemical sensing. In the present work TiO₂ nanoparticles have been used for a self-assembling procedure to realize lined-up micro-patterned titanium oxide films. The high surface-to-volume ratio makes these structures suitable to adsorb gases. Morphological, compositional and structural characterization have been performed in order to determine the features of the assembling. The analysis of electrical behaviour of the ordered films in controlled atmosphere allowed us to test the gas sensing properties.     

低温氧化锆氧传感器的研究

研究了一种新型氧化锆氧传感器－低温氧传感器。它以氧化钇稳定的氧化锆作电池，以二氧化钌（ＲｕＯ２）代替常规的金属铂（Ｐｔ）作电极，即使工作温度降至３００℃，它仍有较小的电池内电阻和较快的响应速度，其理想工作温度下限比常规氧化锆氧传感器降低了５００℃左右。因此，延长了电池的使用寿命，扩大了该传感器的应用范围。     

Electrokinetic motion of single nanoparticles in single PDMS nanochannels

Electrokinetic motion of single nanoparticles in single nanochannels was studied systematically by image tracking method. A novel method to fabricate PDMS-glass micro/nanochannel chips with single nanochannels was presented. The effects of ionic concentration of the buffer solution, particle-to-channel size ratio and electric field on the electrokinetic velocity of fluorescent nanoparticles were studied. The experimental results show that the apparent velocity of nanoparticles in single nanochannels increases with the ionic concentration when the ionic concentration is low and decreases with the ionic concentration when the concentration is high. The apparent velocity decreases with the particle-to-channel size ratio (a/b). Under the condition of low electric fields, nanoparticles can hardly move in single nanochannels with a large particle-to-channel size ratio. Generally, the apparent velocity increases with the applied electric field linearly. The experimental study presented in this article is valuable for future research and applications of transport and manipulation of nanoparticles in nanofluidic devices, such as separation of charged nanoparticles and DNA molecules.     

一氧化氮电化学传感器研究进展

一氧化氮(NO)的诸多检测方法中,电化学传感法因具有灵敏度高、操作简便、检测快速等优点而备受关注.近年来,NO电化学传感器的研究进展主要集中于新型NO敏感功能材料的制备、表征及其应用.敏感功能材料主要包括碳纳米材料、金属及金属氧化物纳米颗粒、过渡金属配合物和导电聚合物四大类.将这些敏感功能材料进行归纳总结,对于新型高性能NO电化学传感器的研发具有重要的指导意义.     

Nanoparticles in polymer-matrix composites

Regarding the development of nanoparticles for polymer matrix composites the particle/agglomerate size and particle/agglomerate distribution in the composites, respectively, is often crucial. This is exemplarily shown for, e.g. optical applications with measurements of refractive index and transmittance. Classical blending techniques, where nanoparticles are dispersed in polymers or resins, are compared to a combination of a special gas-phase synthesis method with subsequent in-situ deposition of nanoparticles in high-boiling liquids. The particles/agglomerates were characterized regarding particle size and particle size distribution using transmission electron microscopy and dynamic light scattering. Additionally, important material properties like mechanical properties, relevant for application, or like viscosity, relevant for processing, are determined. It is shown, that with in-situ dispersed nanoparticles synthesized in a microwave plasma process composites with finely dispersed particles/agglomerates are attainable.     

Drop-on-demand inkjet printing of alumina nanoparticles in rectangular microchannels

A procedure has been developed for applying a piezoelectric drop-on-demand inkjet printing technology to deposit metal oxide nanoparticles such as alumina in stainless steel microchannels. The printability of inks having different solid concentrations, co-solvents, hydro-soluble polymers, viscosities, and surface tensions was tested. The effect of piezoelectric activation parameters on properties of generated microdrops such as drop size and velocity was investigated. Depending upon the ink composition, three different types of coated film shapes were observed in rectangular microchannels. A uniform coating in rectangular microchannels was achieved by correctly tuning the directional stability of microdrop, ink composition, and microdrop properties. It is observed that drying effects such as coffee ring effect have a large impact on the final shape of the deposited alumina layers. The adhesion of printed alumina layers was tested after drying and calcination in harsh environments such as ultrasonic baths, and it was satisfactory.     

Zeta-potential Analyses using Micro Electrical Field Flow Fractionation with Fluorescent Nanoparticles

Increasingly growing application of nanoparticles in biotechnology requires fast and accessible tools for their manipulation and for characterization of their colloidal properties. In this work we determine the zeta-potentials for polystyrene nanoparticles using micro electrical field flow fractionation (mu-EFFF) which is an efficient method for sorting of particles by size. The data obtained by mu-EFFF were compared to zeta potentials determined by standard capillary electrophoresis. For proof of concept, we used polystyrene nanoparticles of two different sizes, impregnated with two different fluorescent dyes. Fluorescent emission spectra were used to evaluate the particle separation in both systems. Using the theory of electrophoresis, we estimated the zeta-potentials as a function of size, dielectric permittivity, viscosity and electrophoretic mobility. The results obtained by the mu-EFFF technique were confirmed by the conventional capillary electrophoresis measurements. These results demonstrate the applicability of the mu-EFFF method not only for particle size separation but also as a simple and inexpensive tool for measurements of nanoparticles zeta potentials.