Among different sensing platforms, metamaterials composed of subwavelength or deep subwavelength sized metal resonance elements arrays that are etched on semiconductor substrates or dielectric substrates exhibit excellent characteristics due to the strong localization and enhancement of resonance electromagnetic fields. As a new type of detection method, metamaterial sensors can break through the resolution limit of traditional sensors for a small amount of substance and have the advantages of high sensitivity, fast response, and simple measurement. Significant enhancement of the sensing characteristics of metamaterial sensors was realized by optimizing microstructures (single split-ring, double split-ring, nested split-ring, asymmetric split-ring, three-dimensional split-ring, etc.), using ultrathin substrates or low-index substrate materials, etching away local substrate, and integrating microfluidic channel, etc. This paper mainly reviews the research advance on the improvement of sensing characteristics from optimizing resonance structures and changing substrate materials and morphology. Furthermore, the sensing mechanism and main characteristic parameters of metamaterial sensors are introduced in detail, and the development trend and challenge of metamaterial sensing applications are prospected. It is believed that metamaterial sensors will have potential broader application prospects in environmental monitoring, food safety control, and biosensing in the future.

中文翻译：

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基于电磁超材料的折射率传感器传感特性研究进展

在不同的传感平台中，由亚波长或深亚波长尺寸的金属谐振元件阵列组成的超材料蚀刻在半导体基板或介电基板上，由于谐振电磁场的强定位和增强而表现出优异的特性。超材料传感器作为一种新型的检测方法，可以突破传统传感器对少量物质的分辨率限制，具有灵敏度高、响应速度快、测量简单等优点。通过优化微结构（单裂环、双裂环、嵌套裂环、不对称裂环、三维裂环等），使用超薄基板或超材料传感器，显着提高了超材料传感器的传感特性。低折射率基板材料，蚀刻局部基底、集成微流控通道等。本文主要综述了从优化共振结构和改变基底材料和形貌等方面改善传感特性的研究进展。此外，详细介绍了超材料传感器的传感机理和主要特征参数，展望了超材料传感应用的发展趋势和挑战。相信未来超材料传感器在环境监测、食品安全控制、生物传感等方面具有潜在的更广阔的应用前景。本文主要综述了从优化共振结构和改变基板材料和形貌来改善传感特性的研究进展。此外，详细介绍了超材料传感器的传感机理和主要特征参数，展望了超材料传感应用的发展趋势和挑战。相信未来超材料传感器在环境监测、食品安全控制、生物传感等方面具有潜在的更广阔的应用前景。本文主要综述了从优化共振结构和改变基板材料和形貌来改善传感特性的研究进展。此外，详细介绍了超材料传感器的传感机理和主要特征参数，展望了超材料传感应用的发展趋势和挑战。相信未来超材料传感器在环境监测、食品安全控制、生物传感等方面具有潜在的更广阔的应用前景。