一种压阻式微悬臂梁免疫传感器及其动力学分析

针对传统光学读出微悬臂梁传感器所需测量系统复杂的局限,将生物素—亲和素系统的放大效应与压阻式微悬臂梁传感技术结合起来,成功构建了一种读出方式简单的压阻式微悬臂梁免疫传感器。利用构建的传感器对相思子毒素进行检测,检测限达8μg/L,反应在20 min内基本完成,具有很好的特异性和重现性,能满足水样、土壤、食品等实际模拟样品检测的要求。建立了压阻式微悬臂梁免疫传感器检测相思子毒素的反应动力学模型,并对实际检测数据进行了拟合分析,相关系数R值在0.971 1以上(P0.001)。根据拟合方程求出的传感器对不同浓度相思子毒素反应达到平衡的响应电压ΔU e、响应时间t0均与实测值非常接近。     

用于化学气体检测的压阻检测式二氧化硅微悬臂梁传感器

文中演示了一种高分辨率的压阻检测式二氧化硅微悬臂梁传感器及其制作方法,并利用该传感器实现了对化学气体的检测.通过传感器在线检测以及其它表征手段,验证了该传感器通过单分子自组装方法获得敏感层的可行性.经过Cu2 /巯基十一酸单分子自组装层修饰的微悬臂梁传感器可以对甲基膦酸二甲酯(DMMP)气体进行快速响应,最小检测浓度可达数ppb(×10-9).     

应力型微悬臂梁生化传感器响应机理研究进展

针对静态微悬臂梁表面特异性结合产生表面应力信号的响应机制问题,介绍了微悬臂梁生化传感器的工作原理,阐述了应力响应机制的简化模型,从纵向界面上和横向分子间2个方面对特异性吸附引起的悬臂梁表面应力的变化进行了剖析,讨论了界面能变化、位阻作用、静电力、氢键作用等与表面应力大小及方向之间的关系,总结了应力型微悬臂梁生化传感器的响应机理的研究。     

谐振微悬臂梁传感器的工作原理及其在生化检测中的研究进展

谐振微悬臂梁是一种可以将质量变化转换为频率信号的微质量型传感器，因其分辨率高、灵敏度高、成本低、易于集成和小型化等优点而备受关注。谐振微悬臂梁现已被广泛应用于流量控制、生物医学痕量检测、气态和液态分子分析等领域。近年来，随着微机电系统（Micro-Electro-Mechanical System,MEMS）技术的快速发展，针对谐振式微悬臂梁传感器的研究与应用越来越多，对近年来谐振式微悬臂梁传感器在环境检测、生物医学等领域的具体应用进行了综述，并对未来的发展方向做出了展望。     

检测棉条用压阻式传感器

提出了适用于纺织机械中的并条机、梳棉机等前纺设备的棉条在线检测及纺织质量检测的一种压阻式传感器。给出了传感器的结构模型和实测数据。在棉条质量检测上 ,具有精度高、线形度好、灵敏度高及动态性能好等特点     

用于痕量胺类同系物检测的谐振式微悬臂梁传感器

采用化学修饰法,将酸性羧基基团嫁接于高比表面的积的SBA- 15介孔材料中,然后将该功能化介孔材料负载于集成谐振式微悬臂梁表面,制得一种高性能的挥发性胺类同系物传感器.胺类分子的吸附将导致质量型微悬臂梁传感器谐振频率的下降,传感器检测下限可达ppb量级.对一系列胺类同系物的检测结果表明,胺类分子在羧基功能化介孔表面的吸...     

压力传感器动态性能分析及改进

传感器的动态性能是否符合要求对测试结果的准确性至关重要。通过压阻式压力传感器的动态校准实验数据，建立其动态数学模型，并由此求出动态特性指标，最后设计出动态补偿数字滤波器，明显提高了传感器动态响应的快速性和展宽了工作频带。     

基于DBN的硅压阻式压力传感器高精度温度补偿模型的研究

硅压阻式压力传感器因对温度具有敏感性,工作时受环境温度的影响会产生温度漂移现象,降低了测量精度,为提升压力传感器的检测精度,提出了一种基于深度信念网络(Deep Belief Network,DBN)的高精度温度补偿模型.研究了压阻式压力传感器的工作原理和温度补偿的数学模型,利用深度学习强大的数据表征能力,设计了区间定位的温度补偿模型构建算法,建立并优化DBN模型的网络结构,将DBN温度补偿模型对实验数据进行训练拟合,结果表明:温度补偿后的满量程相对误差由原来的7.013×10-3提升至8.240×10-5,验证了所提出的方法能具有较好的稳定性和温度补偿效果,较大幅度地提升了传感器的检测精度.     

分子印迹技术在水质检测传感器领域的应用

分子印迹技术是制备具有特异识别能力聚合物(分子印迹聚合物)的新兴化学合成技术,分子印迹聚合物可作为传感器识别元件,用于制备水质检测传感器。总结了分子印迹技术在水质检测传感器领域的应用研究现状,探讨了其发展趋势,指出以分子印迹聚合物作为敏感识别元件的水质检测传感器具有快速、准确、稳定和可反复利用等优点,可用于检测水体中农药、除草剂、神经毒剂以及无机离子化合物等,是实现水质现场快速检测的重要技术途径。     

产品介绍

MLG—2型加速度传感器是利用半导体材料的压阻效应,采用半导体集成工艺制成。由于设计制作了技术指标先进的ML型力敏应变片与集中应力式悬臂梁,因而该传感器具有体积小、重量轻、灵敏度高、低频响应好等特点,为目前加速度传感器中最新一代产品。用于检测低g值振动加速度。配合适当电路可测量振动速度     

Design and analysis of piezoresistive microcantilever for surface stress measurement in biochemical sensor

Piezoresistive microcantilever has been proposed to measure the surface stress generated by biochemical analytes. Such in situ measurement is desirable for biochemical sensors with on-chip microsystem integration. A two-dimensional model is presented to analyze the four-layer piezoresistive microcantilever subject to the surface stress effect generated by biochemical reaction and the thermal effect induced by the piezoresistive layer. Analysis shows that both effects are detrimental to sensor measurement. Conventional wisdom by changing the aspect ratio of a microcantilever is futile to achieve higher sensitivity. An improved design by having the stripe pattern on the immobilized layer is developed to increase the measurement sensitivity. Higher sensitivity can also be obtained by having thicker bottom insulation layer and thinner piezoresistive layer. It is shown that the microcantilever design is superior to the stress concentration region (SCR) design commonly seen in atomic force microscopy (AFM).     

Determination of exposure to engineered carbon nanoparticles using a self-sensing piezoresistive silicon cantilever sensor

A novel MEMS-based cantilever sensor with slender geometry is designed and fabricated to be implemented for determining personal exposure to carbon engineered nanoparticles (NPs). The function principle of the sensor is detecting the cumulative mass of NPs deposited on the cantilever surface as a shift in its resonant frequency. A self-sensing method with an integrated full Wheatstone bridge on the cantilever as a piezoresistive strain gauge is introduced for signal readout replacing optical sensing method. For trapping NPs to the cantilever surface, an electrostatic field is used. The calculated equivalent mass-induced resonant frequency shift due to NPs sampling is measured to be 11.78?±?0.01?ng. The proposed sensor exhibits a mass sensitivity of 8.33?Hz/ng, a quality factor of 1,230.68?±?78.67, and a temperature coefficient of the resonant frequency (TC _f ) of ?28.6?ppm/°C. These results and analysis indicate that miniaturized sensors based on self-sensing piezoresistive microcantilever can offer the performance to fulfill the requirements of real-time monitoring of NPs-exposed personnel.     

Investigation on the effect of different design of SCR on the change of resistance in piezoresistive micro cantilever

This paper presents the investigation on the effect of different designs of Stress Concentration Region (SCR) on the change of resistance in piezoresistive microcantilever using Finite Element (FE) analysis. Two steps solution using memMech and memPzr solvers in Conventor is used in FE analysis in order to obtain the resistance change directly from microcantilever. Simulation results show that cantilever with SCR circle design gives the desired highest magnitude and broader stress distribution region thus contributing to the most significant result for piezoresistive effect.     

微悬臂梁压阻桥式传感器的微弱信号检测技术研究

针对微悬臂梁压阻桥式传感器的输出信号非常微弱的特点,设计了基于该类传感器的微弱信号检测电路,采用锁相放大技术来提取淹没在强噪声背景下的微弱信号,通过理论和实验证明:该设计方法很好地提取了反映变化量性质的有用信号,同时也很好地提高了系统的信噪比,满足了实际情况的需要。     

Embedding conductive patterns of elastomer nanocomposite with the assist of laser ablation

This work introduces a simple and low-cost microfabrication technique utilizing laser ablation to embed conductive elastomer nanocomposite within an insulating bulk elastomer. Nanocomposite consisting of poly(dimethylsiloxane) and a network of carbon nanotubes functions as a piezoresistive sensor material. Microstructures are embedded with the assist of laser ablation which utilizes a focused laser beam to ablate through a thin polymer film following a path programmed via software. This approach eliminates hardware such as photo-mask or stamp, which offers distinct advantages in reducing fabrication time and cost in prototyping of sensor devices. Various patterns of polymer film and embedded nanocomposite are demonstrated with spatial resolution down to 34 μm. To characterize patterning quality, different fabrication conditions are tested and uniformity (width, thickness) data are measured with optical profiling. Sensor prototypes are demonstrated based on the piezoresistive response of nanocomposite under tensile strain. Strain sensors could detect large-range (>45%) tensile strain with sensing a factor of about 4, showing promising feasibility for various sensing applications.     

平面内谐振式微悬臂梁生化传感器的设计与制造

给出了一种新型的基于平面内谐振模态的电热驱动微悬臂梁的工作原理和制造方案。相比于传统的平面外谐振模态谐振式悬臂梁,该设计能有效地降低微悬臂梁在液体中工作时的拖曳力,从而降低其振动能量损失,使得其接入锁相环接口电路后的闭环品质因数达到了249。电热驱动和压阻检测方式便于工艺集成和快速检测。本文给出了基于SOI硅片和深反应离子刻蚀(DRIE)的悬臂梁制作方案,并分别在空气和水中对悬臂梁的谐振特性进行了测试。     

Improved All-Silicon Microcantilever Heaters With Integrated Piezoresistive Sensing

This paper presents the design, fabrication, and characterization of improved all-silicon microcantilever heaters with integrated piezoresistive sensing. The fabricated microcantilever heaters with piezoresistors are made solely from single crystal silicon with selective doping. Detailed characterization was performed to test the devices' electrical, thermal, and mechanical properties. The performance of and crosstalk between heater and piezoresistor elements were thoroughly tested. The resistive heater could reach temperatures of > 600degC, and its temperature coefficient of electrical resistance was (2.01 plusmn 0.04) times 10^-3 Omega/Omega ldr degC. When biased at 2 V in a Wheatstone bridge, the deflection sensitivity of the piezoresistor was (4.25 plusmn 0.05) times 10^-4 V/V ldr mum and remarkably, the heater circuit had a measurable deflection sensitivity of (7.9 plusmn 0.5) times 10^-5 V/V ldr mum. Both the piezoresistor and the resistive heater were interfaced with a commercial atomic force microscope system to measure their sensitivities during topography imaging. The sensitivity of the thermal reading was much greater than that of piezoresistive reading. Noise-limited resolution of thermal reading was better than 0.46 plusmn 0.03 nm/radicHz and piezoresistive reading was better than 3.4 plusmn 0.4 nm/radicHz. This is the first experimental comparison between thermal and piezoresistive topographic sensing, both of which can replace optical lever sensing. Four cantilevers in an array demonstrated parallel topographic sensing with both the heater and the piezoresistor.     

Fabrication and temperature coefficient compensation technology of low cost high temperature pressure sensor

For the purposes of pressure measurement at high temperature in oil drilling industry as well as in other industrial measurement and control systems, the strain gauge chip of piezoresistive pressure sensor is designed based on separation by implanted oxygen (SIMOX) SOI (silicon on insulator) technology, and then fabricated in the micro-machining work bay. Some kinds of sensor mechanical structures are designed for different customers and conditions. The thermal coefficients of expansion (TCE) mismatches between different materials within the high-pressure sensor system are investigated. The sensor is fabricated successfully by using high temperature packaging process. The temperature coefficient of sensitivity (TCS) and temperature coefficient of offset (TCO) compensation circuitry is demonstrated. Based on experimental data, the sensor is tested with high accuracy and good stability.     

Design, fabrication, and testing of VDP MEMS pressure sensors

In this paper, a four-terminal piezoresistive sensor commonly known as a van der Pauw (VDP) structure is presented for its application to MEMS pressure sensing. In a recent study, our team has determined the relation between the biaxial stress state and the piezoresistive response of a VDP structure by combining the VDP resistance equations with the equations governing silicon piezoresistivity and has proposed a new piezoresistive pressure sensor. It was observed that the sensitivity of the VDP sensor is over three times higher than the conventional filament type Wheatstone bridge resistor. To check our theoretical findings, we fabricated several (100) silicon diaphragms with both the VDP sensors and filament resistor sensors on the same wafer so both the sensor elements have same doping concentration. Several diaphragms had VDP sensors of different sizes and orientations to find out their geometric effects on pressure sensitivity. The diaphragms were subjected to known pressures, and the pressure sensitivities of both types of sensors were measured using an in-house built calibration setup. It was found that the VDP devices had a linear response to pressure as expected, and were more sensitive than the resistor sensors. Also, the VDP sensors provided a number of additional advantages, such as its size independent sensitivity and simple fabrication steps due to its simple geometry.