Mechano-Tunable Chiroptics of Single Crystalline Metal Helices Made by Superelastic Nanomolding Technique

Active chiral plasmonics show promise for chiral sensing and light generation applications. While progress in fabricating chiral plasmonic nanostructures has advanced, their fixed chiroptic properties limit device functionality, and structure-chiroptic correlations remain poorly understood. a superplastic nanomolding technique is introduced to form single-crystalline metal helices. Single-crystalline silver helices demonstrate strong chiroptic responses with dissymmetry factors up to ≈0.4, matching simulations. By mechanically manipulating individual helical nanowires, reversible tuning of chiroptic responses is achieved, and reveal structure-chirality correlations. This approach offers a scalable fabrication method for mechano-tunable single-crystalline metal helices while providing design guidelines for improved chiroptic sensing and detection devices.