多谐振型太赫兹超材料生物传感器研究

发布时间：2018-01-17 20:00

本文关键词：多谐振型太赫兹超材料生物传感器研究　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：超材料是由周期性排列的亚波长单元阵列所构成的新型人工复合型电磁材料,具有自然界中常规材料所不具备的特殊电磁特性,如负折射率、负介电常数、反多普勒效应等。其中,谐振型超材料具有微纳尺寸缝隙,可显著增强局域电磁场强度,对周围环境的介电特性变化特别敏感。因此,谐振型超材料可广泛地应用于传感探测领域。同时,太赫兹波的光子能量相对较低,能够激发生物分子的集体震荡模式,可增强对生物分子的探测的灵敏度;另外,大多数生物分子在太赫兹波段具有特定的指纹谱,在识别和探测生物分子方面具有独特的优势。基于上述原因,本文设计了两种不同结构的太赫兹超材料传感器,分别为基于互补型双谐振和基于吸收器的多谐振的太赫兹超材料生物传感器,并采用基于有限元方法的数值仿真软件HFSS分别对两种传感器的灵敏度进行模拟计算和数值优化分析,其主要研究工作如下:1.设计一种基于互补型双谐振超太赫兹材料生物传感器,其结构单元由圆环间隙构成。采用数值仿真软件对传感器的结构参数进行优化,并对其表面电流和电场分布进行模拟计算。表面电流和电场分布证明:双谐振分别来源LC谐振和电偶极子谐振。在此基础之上,分析了附着物的厚度和折射率对其传感性能的影响,计算结果表明:该传感器对附着物的折射率和厚度变化非常灵敏,其灵敏度远大于单谐振型太赫兹超材料传感器的灵敏度。2.由于超材料吸收器的吸收峰具有非常窄的半波带宽度(FWHM),并对外界环境的变化具有较高的灵敏度,设计了一种基于吸收器的三谐振型太赫兹超材料生物传感器,其结构单元由上下对称的双开口环构成。利用仿真软件优化吸收器的结构参数和电磁特性,探究吸收器的吸收机理,并分析其传感性能。表面电流和能流分布显示:三种谐振模式分别为LC谐振、四偶极子谐振和电偶极子谐振。模拟计算结果表明:三种谐振模式都具有较高的吸收率和灵敏度,并且其灵敏度远大于通过组合或堆叠而成的多谐振吸收器的灵敏度。
[Abstract]:Metamaterials are a new type of artificial composite electromagnetic materials composed of periodic array of subwavelength elements, which have special electromagnetic properties, such as negative refractive index and negative dielectric constant, which are not possessed by conventional materials in nature. The resonant supermaterial has micro-nano size gap, which can significantly enhance the local electric magnetic field intensity, especially sensitive to the change of the dielectric characteristics of the surrounding environment. The resonant supermaterial can be widely used in the field of sensing detection. At the same time, the photonic energy of terahertz wave is relatively low, which can excite the collective oscillation mode of biomolecules and enhance the sensitivity of detecting biomolecules. In addition, most biomolecules have a specific fingerprint spectrum in terahertz band and have unique advantages in identifying and detecting biomolecules. In this paper, two kinds of terahertz supermaterial biosensors with different structures are designed, one is based on complementary double resonance and the other is based on absorber. The sensitivity of the two sensors is simulated and optimized by the finite element method (FEM) based numerical simulation software HFSS. The main research work is as follows: 1. Design a kind of material biosensor based on complementary double resonance ultra terahertz material. The structure unit is composed of ring clearance. The structural parameters of the sensor are optimized by numerical simulation software. The surface current and electric field distribution are simulated and calculated. It is proved that the double resonance comes from LC resonance and electric dipole resonance respectively. The effect of the thickness and refractive index of the attachment on the sensing performance is analyzed. The calculation results show that the sensor is very sensitive to the change of the refractive index and thickness of the attachment. Its sensitivity is much higher than that of single resonant terahertz supermaterial sensor. 2. Because the absorption peak of the supermaterial absorber has very narrow half-band width FWHM). A three resonant terahertz metamaterial biosensor based on absorber is designed because of its high sensitivity to the change of external environment. The structure unit is composed of a double open loop with symmetry up and down. The structure parameters and electromagnetic characteristics of the absorber are optimized by the simulation software, and the absorption mechanism of the absorber is explored. The sensor performance, surface current and energy flow distribution show that the three resonant modes are LC resonance respectively. Four dipole resonance and electric dipole resonance. The simulation results show that the three resonant modes have high absorptivity and sensitivity. And its sensitivity is much higher than that of multi-resonance absorber formed by combination or stacking.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.3

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