Fig. 5: Laser-printed Pt-ZnO-Ag security circuits.
a Schematic of an embedded hardware-based security primitive, based on a physically unclonable function (PUF). b Optical micrograph of a laser-printed \(6\times 6\) crossbar array with contact pads. c Scanning-electron micrograph of a laser-printed \(6\times 6\) crossbar array, showing a period of 1.5 µm in both, horizontal and vertical directions. The memristive devices are located at the wire crossing junctions. d Activation of the 36 memristor cells by sweeping a voltage from \(0\,{{{{{\rm{V}}}}}}\to 10\,{{{{{\rm{V}}}}}}\to -4\,{{{{{\rm{V}}}}}}\to 0\,{{{{{\rm{V}}}}}}\). The inset shows the set process of the 36 memristor cells for positive voltages, with the compliance current set to \(1{{{{{\rm{mA}}}}}}\). e False-color representation of the read-out currents \({I}_{{{{{{\rm{read}}}}}}}\) from the \(6\times 6\) array. f Retention performance of \({I}_{{{{{{\rm{read}}}}}}}\) over a timespan of 60 s. g Circuit architecture around the core of the memristor-PUF. h Bit-array distribution corresponding to the \(6\times 6\) crossbar array. i Schematic of the evaluated bit errors over 300 cycles.
