Insulation Sensing and Detection Based on Dual-Band Terahertz Metamaterials

In order to detect the state of insulating materials with high sensitivity, a dual-band THz metamaterial sensor is proposed and prepared by micro-nano lithography. The sensor demonstrates two prominent resonant peaks at 0.976 THz and 1.65 THz across the 0.1-1.8 THz spectrum. Functioning dually as a thickness and refractive index detector, the optimized design exhibits exceptional sensing performance at both resonant frequencies. For insulating materials with a 10μm thickness, the sensor”s frequency shift maintains a linear relationship with refractive index variations, yielding sensitivities of 1 78.6 GHz/RIU and 160 GHz/RIU, while achieving a maximum quality factor (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex>) of 50. Experimental validation using THz time-domain spectroscopy (THz- TDS) revealed close alignment with simulation results, with systematic error analysis ensuring reliability. Featuring a compact structure, high sensitivity, and strong anti-interference capability, the sensor, when integrated with THz- TDS, holds significant potential for advancing insulation material state detection in industrial applications.