植入式葡萄糖传感器的模拟分析

介绍一种植入式葡萄糖传感器的模型。对糖尿病患者的血糖或组织糖浓度的连续监测是生物传感器的重要应用。由于影响传感器设计的因素很多,反复实验优化传感器的研究是很耗时的。使用此模型,对传感器测量特性(校正曲线、测量范围,灵敏度)与传感器设计参数(几何形状,尺寸)的关系进行了模拟。使用系统的计算模拟方法可以对植入葡萄糖传感器特性优化。     

用生物传感器对葡萄糖互变 异构动力学的研究

报道一种新的用生物传感器测定Ｄ－葡萄糖互变系数的方法，该生物传感器由固定葡萄糖氧化酶酶膜和流动注入分析式氧电极所组成，传感器测得的互变系数与旋光法测定的和文献上所给出的数值基本上符合，并验证磷酸根对Ｄ－葡萄糖互变反应有催化作用，其互变系数与浓度呈线性关系。     

基于空心微针阵列的连续监测葡萄糖传感器

研制了一种基于空心微针阵列并可微痛刺入皮下实时连续监测人体血糖浓度的葡萄糖传感器.微针阵列由等间距的三根微针组成,分别作为工作电极、辅助电极和参比电极,其中工作电极与辅助电极采用表面溅射了Ti/Pt的空心不锈钢微针来制作,采用戊二醛-牛血清白蛋白交联法将葡萄糖氧化酶固定并仅置于作为工作电极的针尖通孔处;参比电极采用Ag/AgCl实心微针制作.测试结果表明:葡萄糖浓度在0～21 mmol·L-1范围内传感器输出电流为线性,灵敏度为0.575 μA/(mmol·L-1),响应时间为16s,且具有很好的抗干扰性.     

碳纳米管/PDMS复合材料柔性阵列压力传感器制备与实验

以碳纳米管（CNTs）作为导电填料,聚二甲基硅氧烷（PDMS）为基体材料,采用溶液法制备出CNTs/PDMS导电复合材料。研究了碳纳米管浓度对复合材料的电学特性和压阻特性的影响规律,得到碳纳米管在PDMS中的渗滤区域。通过复合材料的压力灵敏度优化碳纳米管浓度。以制备的复合材料为敏感材料,FPCB工艺加工的柔性基板为电极,设计制备了一种简单结构和工艺的柔性阵列压力传感器。用零电势法设计了阵列电阻读出电路与LabVIEW实现的上位机配合,实现信号读取和显示。最后通过一个应用实例表明,该柔性阵列压力传感器及信号处理系统可以实现压力分布与大小的实时监测,可为柔性阵列压力传感器设计与制备提供参考。     

PI电容温度传感器结构改进与性能分析

本文分析了电容型湿度传感器的电极和感湿膜的几何形状,设置感湿膜单元结构为圆柱体或者瓶径体等形状,增大接触面积以减少响应时间,整体感湿膜单元排列成圆环形阵列,上电极也采用圆环形阵列排列,覆盖在感湿单元阵列上方。最后对设计的传感器灵敏度,响应时间等性能进行了分析,得出了有益的结论。     

基于铂纳米线阵列的葡萄糖生物传感器

用电沉积法在聚碳酸酯膜板中制备了铂纳米线阵列,纳米线直径约为250 nm,长度约为2 μm.SEM表征表明,铂纳米线阵列具有均匀有序的结构,纳米线密度为5×108 cm-2.将纳米线阵列薄膜固定到电极表面,研究了修饰电极的电化学行为.在较低电位下(-0.1 V),修饰电极对过氧化氢具有良好的电催化性能,并有较宽的线性响应范围(1×10-7～5×10-2 mol/L).通过戊二醛在电极表面固定葡萄糖氧化酶制备了一种新的葡萄糖传感器.该传感器对葡萄糖的线性响应范围为5×10-6～2×10-3 mol/L,检测下限为1 μmol/L.     

PI电容湿度传感器结构改进与性能分析

本文分析了电容型湿度传感器的电极和感湿膜的几何形状,设置感湿膜单元结构为圆柱体或者瓶径体等形状,增大接触面积以减少响应时间,整体感湿膜单元排列成圆环形阵列,上电极也采用圆环形阵列排列,覆盖在感湿单元阵列上方.最后对设计的传感器灵敏度,响应时间等性能进行了分析,得出了有益的结论.     

双阵列式电容传感器特性研究

针对电容层析成像技术的局限性,提出了新型双阵列电容传感器。利用传感器相邻极板灵敏度不均匀的特点,通过测量相邻极板电容以获得传感器内部局部浓度,重建管道内部传感器截面的相浓度分布。建立有限元模型,对不同电极数的电容传感器结构进行分析,研究了管道介电常数、电极覆盖率等传感器参数对灵敏场不均匀度的影响,得出优化的传感器参数。实验结果显示,该方法可以有效获取传感器截面局部浓度。     

SO I 单晶硅压力传感器模拟计算与优化设计

利用有限元分析方法，借助ANSYS软件，对SOI单晶硅压力传感器进行一系列的分析和计算机模拟，探讨了传感器应变膜在固定宽度或固定面积条件下，宽长比对理论输出的影响，以及应变膜厚度对理论输出的影响，给出了设计应变膜的优化方案；并对根据模拟结果首次制作的SOI单晶硅压力传感器进行了测量，结果与理论值符合得较好。     

一种新场发射压力传感器阳极膜结构的模拟与测试

提出了场发射压力传感器阳极变形膜的双层膜结构.计算机模拟证明这种结构与已报道的单层膜相比具有大量程与高灵敏度的优点.对这种结构的形变特性进行了实验测试,考虑到测量误差与湿法刻蚀造成膜表面的不平整因素,测实结果与模拟结果较为相符.     

Performance of glucose biosensor based on oxygen electrode in physiological fluids and at body temperature

A potentially implantable glucose biosensor for continuous monitoring of glucose levels in diabetic patients has been developed. The glucose biosensor is based on an amperometric oxygen electrode and glucose oxidase immobilized on carbon powder held in the form of a liquid suspension. The enzyme material can be replaced (the sensor recharged) without sensor disassembly. Diffusion membranes made of silastic coatings over a microporous polycarbonate membrane are used. Calibration curves of the sensors in phosphate buffer solution and in undiluted blood plasma at body temperature have been obtained. The reproducibility of the sensor response in serum at body temperature is demonstrated. The sensors have a stable signal during storage and continuous operation at body temperature for a period of at least one month.     

钢水成分传感器及其应用进展

本文主要介绍近年来钢水定氧、氮、氢和铁水定硅、硫传感器的技术进步及其应用进展.目前氧传感器的应用已经很成熟,但国产氧传感器在稳定性和测量范围尤其是低氧浓的测定上还应改进.基于氧化锆固体电解质氧浓差电池的铁水中硅、硫传感器也已经实用.基于质谱分析的钢中多气体在线分析为钢中气体的全分析提供了新途径.     

Optochemical hydrogen peroxide sensor based on oxygen detection

A novel hydrogen peroxide sensor based on an optochemical oxygen sensor is presented. An oxygen sensitive membrane is covered with an additional layer containing inorganic catalysts which decompose hydrogen peroxide to water and oxygen. The oxygen is detected in the underlying oxygen sensitive membrane via luminescence quenching. The investigated concentration range for the reported sensor was between 0.1 and 2 wt.% hydrogen peroxide in water. Several catalysts were tested for this application with manganese dioxide being the preferred material. In addition to this, it was shown that by coating the sensor with a proper polymer layer, the hydrogen peroxide sensitivity could be improved up to five times compared to an uncoated sensor. The response times of the sensors depends on the type of covering layer, with the shortest response times being similar to that of uncoated sensors (t₉₅ was approximately 1 min for a change from 0 to 0.2 wt.% hydrogen peroxide in water).     

平板式二氧化锆氧传感器的研究进展

由于日益严格的排放法规,平板式二氧化锆氧传感器将成为汽车尾气控制应用的主流传感器。介绍了平板式氧传感器的制备工艺、结构和三种平板式氧传感器的工作原理并进行了对比。最后,展望了平板式氧传感器的发展前景。     

基于电化学的固态CO2传感器研究进展

用于检测环境中气体的电位传感器已经在传感器技术领域发展为一个成熟的方向。由于在各个行业有着广泛的应用,可靠廉价的CO2传感器有着巨大的市场潜力。总结了基于电化学的固态CO2传感器类型,分析了它们的检测过程,提供关于其传感原理和特性研发的广泛概述,并描绘了基于电化学的固态CO2传感器在未来各种应用的可能性。     

基于螺旋型铂铱合金电极的植入式葡萄糖生物传感器

采用螺旋型铂铱合金电极设计,旨在提高植入式葡萄糖生物传感器的葡萄糖氧化酶担载量并增大工作电极的电化学活性面积.以扫描电镜(SEM)观察聚氨酯(Polyurethane,PU)半透膜的形貌,采用循环伏安法(CV)和计时电流法(I-T)考察PU涂覆厚度、PU含量以及酶含量等参数对传感器电化学性能的影响,结果表明:所制备的螺旋型传感器灵敏度在20 nA/(mmol/L)~30 nA/(mmol/L),可在人体生理条件范围内线性检测(2 mmol/L~30 mmol/L)葡萄糖浓度,并且具有良好的重现性、稳定性和选择性,符合电极长期植入式需求,有望作为今后糖尿病患者血糖连续监测的关键器件.     

Temperature compensation of fluorescence intensity-based fiber-optic oxygen sensors using modified Stern–Volmer model

In practical sensing applications, temperature effects are of particular concern, and hence it is necessary to develop the means to correct the fluorescence intensity measurement in accordance with the working temperature. Accordingly, this study develops a modified Stern–Volmer model to compensate for the temperature drift of oxygen concentration measurements obtained using fiber-optic sensors. The oxygen sensors considered in this study are based on teraethylorthosilane (TEOS)/n-octyltriethoxysilane (Octyl-triEOS) or n-propyltrimethoxysilane (n-propyl-TriMOS)/3,3,3-trifluoropropyltrimethoxysilane (TFP-TriMOS) composite xerogels doped with platinum meso-tetrakis(pentafluorophenyl)porphine (PtTFPP).

The experimental results are fitted to the modified Stern–Volmer model in order to compute suitable values for a temperature compensation coefficient at different working temperatures. It is found that the proposed temperature compensation method reduces the difference in the oxygen concentration measurement for working temperatures in the range of 25–70 °C as compared to data without compensation. The linearity and sensitivity of PtTFPP-doped n-propyl-TriMOS/TFP-TriMOS sensor are better than PtTFPP-doped TEOS/Octyl-triEOS sensor for working temperatures in the range of 25–70 °C.

The proposed approach could provide a straightforward and effective means of improving the accuracy of fiber-optic oxygen sensors if a variable attenuator is designed according to the temperature compensation coefficient. Thus, the fiber-optic oxygen sensor with a variable attenuator could work in a broad temperature range without using a temperature sensor.     

Multi-range silicon micromachined flow sensor

A new approach of enlarging the measurement range of a thermal calorimetric flow sensor is presented. It is based on the fact that the response of these kind of sensors tends to saturate at a certain flow ratio, so the widening of the flow range can be achieved by increasing the number of sensing elements of the sensor. This implies only a redesign of the flow sensor device, which is fabricated with an existing standard low cost technology. This approach has been implemented achieving measurement ranges from 0.1 up to 8 SLM by placing three different pairs of sensing resistors on the same membrane. Characterisation results and a simulation-based procedure to design flow sensors according to specific applications are included.     

Sensor virtualization for underwater event detection

Distributed event detection is a popular application in Underwater Wireless Sensor Networks (UWSNs). The Base Station (BS) collects the measurements from multiple sensor nodes, and makes a decision based on the sensors’ reports. However, due to the unpredictable moving of underwater sensor nodes and interference among multiple events, it is difficult to guarantee the accuracy of event detection. In this paper, we propose a sensor virtualization approach to deal with the event detection problem in UWSNs. The final decision making at the BS will be implemented with the reports of multiple virtual sensors. Although the events may happen in a large scale, the locations where the events happen are relatively sparse in the underwater environment. Consider the sparse property of events, we employ the technique of compressive sensing to recover the original signal from the correlated sensors’ measurements. Through a proper signal reconstruction, the accurate event detection can be reached with a remarkable low sensing overhead. We implement the sensor virtualization based on the compressive sensing technique. Our approach is suitable for the high dynamic topology of UWSN, and it can improve the accuracy of event detection and reduce energy consumption in UWSNs.