Detection of graphene cracks by electromagnetic induction, insensitive to doping level

Detection of cracks is a great concern in production and operation processes of graphene based devices to ensure uniform quality. Here, we show a detection method for graphene cracks by electromagnetic induction. The time varying magnetic field leads to induced voltage signals on graphene, and the signals are detected by a voltmeter. The measured level of induced voltage is correlated with the number of cracks in graphene positively. The correlation is attributed to the increasing inductive characteristic of defective graphene, and it is verified by electromagnetic simulation and radio frequency analysis. Furthermore, we demonstrate that the induced voltage signal is insensitive to the doping level of graphene. Our work can potentially lead to the development of a high-throughput and reliable crack inspection technique for mass production of graphene applications.