Miniaturization of QR Code Carriers Based on Shape Memory Polymer

Here we present a suitable tag prototype with phase-segregated poly(ester urethane) (PEU) as base material for effectively switching a quick response (QR) code in its surface from non-readable to readable. In comparison with recently introduced tags (different geometry) we minimized the thickness from plaque (2 mm) to foil size (0.5 mm) and reduced the lateral QR code length from 15 to 5 mm. Subsequent to surface-dyeing by means of guest diffusion, the QR code was laser-engraved. The implementation of thermo-mechanical functionalization via tensile deformation and cooling resulted in the formation of stable shapes, which exceeded the barrier of QR code readability at an elongation of 20%. Once functionalized, tags were switched on demand by heating. As such the recovery of the PEU was accomplished and the QR code could again be read out. QR code carriers based on shape memory polymer can be used in product and brand protection applications.