Enhanced Sensing: E7-Liquid Crystal-Based Surface Plasmon Temperature Sensor with Angle Interrogation

The study on temperature sensors based on surface plasmon resonance (SPR) sensors has received less attention than the widespread use of temperature sensors in daily life and industry. As a result, this article proposes an SPR temperature sensor with a structure consisting of gold (Au) film and liquid crystal (LC) film. The application of SPR phenomena in liquid crystals (LCs) for temperature monitoring is investigated in this work. The resonance angle is analyzed in this experiment to detect temperature differences between 15 and 85 °C. The findings show that temperature variations cause appreciable fluctuations in the SPR temperature sensor’s values, exposing the sensitivity of various LC kinds. The simulations revealed slight differences in the resonance angles of TL-216, MLC-9200-000, MLC-6608, E44, and MLC-9200-100 among the LCs under study, which presents a problem for their application as accurate temperature sensors. But when 633 nm and 656 nm wavelengths were considered, the E7 LC showed promise as an efficient temperature sensor within the given temperature range. The study found that the LCs had different sensitivities; the highest sensitivity was measured at 0.249 deg/°C and the lowest at 0.002 deg/°C. The results highlight the potential of SPR-based LCs, particularly E7, as trustworthy temperature sensors within the given temperature ranges, providing information about their possible use in temperature-sensitive settings.