Flexible Temperature Sensor based on Fluorinated Graphene

Graphene derivatives are promising nanomaterials for the development of various flexible electronic devices. In this work, a flexible temperature sensor based on fluorinated graphene (FG) was developed, using screen printing and drop-casting processes. Interdigitated electrodes (IDEs) were fabricated by the deposition of silver (Ag) ink on the polyimide substrate, using the screen printing process, and the FG sensing layer was formed by drop-casting of FG suspension on the IDEs. The resistive response of the temperature sensor towards temperatures varying from 10 °C to 80 °C, in steps of 10 °C, was investigated. The fabricated temperature sensor has a short response time (≤ 2 s) for different target temperature levels. A linear relationship between the relative resistance change (ΔR/R
b
) and the temperature was observed, with a slope of -0.0013/°C and a correlation coefficient of 0.9964. The overall ΔR/R
b
of the sensor was measured as -8.85% when the temperature changed from 20°C to 80 °C. The average temperature coefficient of resistance (TCR) of the temperature sensor was calculated as -0.132 ± 0.005 %/°C for the temperature range of 20 °C to 80 °C.