Highly sensitive and transparent flexible temperature sensor based on nematic liquid crystals
Keming Wu, Jingjing Sun, Lin Gao, Hongyu Xing, Minglei Cai, Tongzhou Zhao, Changyong Yang, Wenjiang Ye, Xiangming Kong
Abstract
In this paper, a highly sensitive and transparent flexible temperature sensor fabricated from the polyethylene terephthalate flexible substrate and the nematic liquid crystal (1M0921900-000) is proposed, which simultaneously has low power consumption. Using the relaxation time (τ = RC) as an intrinsic variable to characterise temperature, a better linear fitting with temperature can be obtained at low voltage, high precision and more stable temperature monitoring can be achieved. The maximum sensitivity is −4.05%/°C at 0.1 V and 200 Hz. The transmittance of the sensor can reach 62.36–81.13% in the visible light range. Compared with the rigid liquid crystal temperature sensor, the rise time and the decay time of the sensor are reduced by 97.104% and 90.313%, respectively. In addition, it also has good stability, recovery, and durability, which shows potential applicability to electronic skin, prostheses, robots, and biomedical by accurately monitoring the change of external temperature.