Flexible Liquid Crystal Thermistor and Its Application in Temperature Sensor

Liquid crystals (LCs) are an excellent material for temperature sensors because of their thermistor properties of negative temperature coefficient (NTC). In this study, a flexible thermistor, made by the indium tin oxide (ITO)-polyethylene terephthalate (PET) flexible substrate and the nematic LC (NLC) NHG715600-100 with negative dielectric anisotropic was presented and its application in temperature sensor was explored. It offers low power consumption, high transparency, high sensitivity, and high accuracy achieved through temperature-resistance characteristics. Using ln ${R}$ as the intrinsic variable for characterizing temperature, the sensor achieves a better non-linear fit to the temperature at low voltages and reaches a maximum sensitivity of −6.615%/K at 0.05 V and 500 Hz. The transmittance reaches 61.29%–92.15% in the visible range, and the rising and fall times respectively reduces by 75.19% and 73.38% compared to the rigid LC thermistor. In addition, it also continues to show remarkable stability, recovery, and durability in various tests. Compared with common thermistors, this device is smaller and lighter in weight, resulting in a wider range of applications in temperature sensing.