Graphene-Based Physically Unclonable Functions with Dual Source of Randomness

There is growing interest in systems with randomizedresponsesfor generating physically unclonable functions (PUFs) in anticounterfeitingand authentication applications. Atomic-level control over its thicknessand unique Raman spectrum make graphene an attractive material forPUF applications. Herein, we report graphene PUFs that emerge fromtwo independent stochastic processes. Randomized variations in theshape and number of graphene adlayers were achieved by exploitingand improving the mechanistic understanding of the chemical vapordeposition of graphene. The randomized positioning of the graphenedomains was then facilitated by dewetting the polymer film, followedby oxygen plasma etching. This approach yielded surfaces with randomlypositioned and shaped graphene islands with varied numbers of layersand, therefore, Raman spectra. Raman mapping of surfaces resultedin multicolor images with a high encoding capacity. Advanced feature-matchingalgorithms were employed for the authentication of multicolor images.The use of two independent stochastic processes on a two-dimensionalnanomaterial platform enables the creation of unique and complex surfacesthat excessively challenge clonability.