Flexible humidity sensor based on light-scribed graphene oxide

The light scribe (LS) technique has been applied to reduce graphene oxide (LSGO) over a flexible substrate to be used as a humidity sensor. Graphene oxide (GO) suspension was drop casted over Polyethylene terephthalate (PET) substrate and then reduced inside a conventional light scribe digital video disc (DVD). Interdigitated electrode was precisely fabricated with dimensions of the finger length of 450 μm and width of 20 μm. The prepared material was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Raman spectroscopy. The results confirm the reduction process of GO using the LS technique. Moreover, the humidity sensing properties of the LSGO was evaluated. Results showed that the present light-scribed humidity sensor has many advantages including rapid response, highly precise due to light scribe technique, and more importantly sensors can be fabricated directly on flexible substrates which are highly favorable for future wearable smart electronics.