Chirality of Fingerprints: Pattern- and Curvature-Induced Emerging Chiroptical Properties of Elastomeric Grating Meta-Skin.

Fingerprint-inspired elastomeric grating meta-skin (EGMS) is herein fabricated to investigate the chirality of fingerprints. The EGMS is made by a facile nanoimprinting method with a diffraction grating as a template using polydimethylsiloxane, followed by gold deposition. The chirality of the surface is caused by symmetry breaking, induced by the pattern (<b><i>P</i></b>) and curvature (<b><i>T</i></b>). Furthermore, the chiroptical properties of EGMS are reconfigurable through the control of the skew angle (θ), which is the angle between <b><i>P</i></b> and <b><i>T</i></b>. The chiroptical properties of a fingerprint are also shown and interpreted in this perspective. On the basis of the results, we suggest the strategy to impart chirality on the surface, which is reconfigurable by controlling <b><i>P</i></b> and <b><i>T</i></b>. It will be a useful method to produce chirality in membranes, thin films, metasurfaces, and 2D nanomaterials, as well as advance biometric recognition.