High-Precision Temperature Sensor System With Mercury-Based Electromagnetic Resonant Unit

Temperature sensing based on emerging techniques, such as the novel electromagnetic resonant unit, has been the vital research direction. However, current works only focused on the initial and principal verifications, and it is far away to the real application. In this article, a temperature sensor based on mercury-inspired electromagnetic resonant unit holding high- $Q$ -factor and with complete circuit system is proposed. The excellent properties of mercury, including the liquid-shape, highly conductivity, and high-temperature sensitivity, are utilized to achieve the effective fusion of such liquid material and high- $Q$ -factor electromagnetic resonant unit, so as to realize the integrated design of high-precision temperature sensing. Furthermore, four functional circuits, including signal generation, temperature sensing, signal reception, and signal processing, are designed and constructed, and finally an integrated mercury-inspired electromagnetic resonant-unit temperature sensor system with good temperature sensing performances is realized. Experimental results show that the temperature measured by the proposed sensor is highly consistent with the actual temperature values, with sensing sensitivity up to 1459 mV/ °C. Such achieved high-precision temperature sensor system can be further integrated and can open a new way for the high-precision environment temperature monitoring in the Internet of Thing (IoT) area.

I. Introduction

Electromagnetic metamaterial is a new type of artificially synthesized structure with novel electromagnetic properties not found in nature. Usually it has anomalous permittivity and magnetic permeability , which can produce many novel and exciting electromagnetic phenomena [1], such as negative refraction, inverse Doppler shift, and inverse Cherenkov radiation effects. Veselago [2] first proposed the concept of electromagnetic metamaterial, but it was not experimentally studied due to the limitations of the research conditions at that time. Pendry et al. [3] constructed the world’s first electromagnetic metamaterial with negative permittivity by using a thin metal wire array, which really opened the way to the research of electromagnetic metamaterials. In recent years, researches on electromagnetic metamaterials have emerged one after another [4], [5], [6], [7], [8], [9], [10], among which the research on sensing application of resonant-type electromagnetic metamaterials stands out due to its superior sensing performances.