Fig. 2: Fabrication procedure of rw-PUF.
From: Voxelated opto-physically unclonable functions via irreplicable wrinkles
a The process of generating random wrinkles. When a liquid crystalline monomer of a reactive mesogen (RM) is spin-coated and cured using plasma, unique and non-replicable wrinkles are formed. (i) Polarized optical microscopy (POM) image showing the as-deposited RMs with random orientation. (ii) An illustration of the wrinkling process. (iii) Optical microscopy (OM) image showing the random wrinkles. b Schematic of the optical setup used for measuring pixelated birefringence of rw-PUF. c Schematic illustrating the conversion of a 2D retardation map to a binary code. All scale bar represents 50 μm
