设计加工了一种太赫兹超材料微流体传感器件, 利用时域有限差分法(Finite Difference Time Domain, FDTD)对其在太赫兹波段的传输、谐振及传感特性进行数值模拟。采用太赫兹时域光谱系统实验研究了偏振方向对传感器灵敏度的影响。实验结果表明, 当超材料谐振环开口方向与入射太赫兹波的偏振方向平行和垂直时, 折射率传感灵敏度可分别达到39.29 GHz/RIU和74.43 GHz/RIU。通过等效电路模型对该超材料器件的传输和谐振特性做了分析, 并进一步明确了其传感机制。该超材料器件可对微量液体(5 μl/mm2)实现芯片式的折射率传感, 具有较高的传感灵敏度, 在化学生物传感器的设计和制造领域具有潜在的应用前景。

A metamaterial device was designed and fabricated for microfluidic sensing in the terahertz regime, its transmission, resonance and sensing properties were numerically simulated in terms of the Finite Difference Time Domain(FDTD). The influence of polarization direction on the sensitivity of sensor was experimentally investigated by terahertz time-domain spectroscopy system. The experimental result shows that when the resonant metamaterial ring opening direction is parallel and perpendicular with the direction of polarization of the incident THz wave, the refractive index sensing sensitivity can reach 39.29 GHz/RIU and 74.43 GHz/RIU, respectively. The transmission and resonance characteristics of the metamaterials are analyzed by the equivalent circuit model to further clarify the sensing mechanism. This THz metamaterial device has the potential applications in sensing chemical and biological component because it is capable of realizing the refractive index sensing of microliquid (5 μl/mm2) with a high sensitivity.