Reduced graphene oxide temperature sensor via photo-thermal laser irradiation for a printed circuit board

Abstract

We report thermal behavior of reduced graphene oxide (rGO) as temperature sensor patterned on a ready-made printed circuit board (PCB). Solution-processable graphene oxide (GO) was drop-casted and reduced by photo-thermal laser irradiation directly on PCBs. Laser irradiation adjusted for appropriate light power reduced GO without destroying electrode patterns and electronic components in PCBs, causing rGO to become a negative thermal coefficient of resistance (TCR). The rGO sensor with electrodes improved contact resistance showed 46% temperature variation from −10 °C to 90 °C. Furthermore, the rGO sensor was fabricated between analogue pin electrodes of commercial Arduino PCBs to measure temperature. An Arduino system showed 13.1% sensitivity to temperature variation from −10 °C to 50 °C detected at the analogue input pin of rGO sensor.