Ionic Liquid-based Temperature Sensor Using Metamaterials for Terahertz Applications

Abstract

This study proposes a terahertz (THz) metamaterial temperature sensor utilizing the thermosensitive ionic liquid BMIM-PF₆. Unlike conventional sensors that rely on frequency shifts, our approach measures temperature-dependent intensity variations at a fixed THz frequency, enabling fixed-frequency measurements without frequency sweeping for seamless integration with 6G communication. By coupling the reflectance intensity response of BMIM-PF₆ with THz metamaterial resonance, we improved the measurement stability using the metamaterial and achieved a temperature resolution of 0.14°C. Experimental evaluations confirmed its feasibility for precise temperature monitoring, demonstrating its potential for next-generation health-monitoring applications.