Graphene as the ultra-transparent conductive layer in developing the nanotechnology-based flexible smart touchscreens

Graphene is the thinnest conductive, transparent, and flexible material with high strain strength which makes it a phenomenological material for many recent nanotechnology-based applications. Due to progress in various growing methods of graphene, especially the chemical vapor deposition (CVD) method which reduced the cost of its fabrication from-200 to 2 euro/cm2 in the last ten years, graphene became an economically efficient alternative for conductive as well as transparent materials previously being used in technological-based applications. Among them, Indium tin oxide (ITO) has been known as an unrivaled material in the touchscreen manufacturing in-dustry for many years, due to its great properties like high transparency and low electrical resistance. However, the low strain strength of ITO and high price of Indium became its bottleneck for recent progressive electronic -based applications requiring high flexibility (e.g., in wearable smart devices) and low cost. Although graphene has still a long way to go to meet the properties needed to make it suitable for smart touchscreen applications, it has a large potential to be used in such technologies. In this paper, the role of CVD-grown graphene in developing smart touchscreen devices and their world market has been reviewed. In addition, various mechanisms of the present smart touchscreens (including the capacitive, resistive, optical, infrared, and surface acoustic wave mechanisms) have been discussed. Finally, some produced graphene-based flexible smart devices applicable for versatile purposes (from smart panels to biological assays) have been introduced.