Reshaping Strategy at Ultrahigh Strain Rates Enables Large‐Scale Fabrication of Sharp Nanostructures

Abstract

AbstractMetal nanostructures are the primary component of metamaterials and plasmonics, whereas the high‐throughput production of high‐resolution nanostructures has always been a challenge. Inspired by the special hardening behavior of nanometals at ultrahigh strain rates, a reshaping strategy of hardened structures for large‐scale fabrication of ultra‐sharp nanostructures is proposed in this study. At ultrahigh strain rates, the extreme shear deformation‐induced solid state amorphization and grain‐refining effects of nanometals are first revealed, which provide the required mechanical properties and structural stability for the reshaping of primary structures. The experimental results demonstrate that nanostructures with sub‐10 nm resolution are formed using the reshaping strategy. Additionally, the pressure dependence of deformation behavior of the hardened structures in the ultrahigh‐strain‐rate reshaping process is further explored to guide the nanofabrication process. The results demonstrate that the reshaping strategy at ultrahigh strain rates allows the ultrafine shaping of nanostructures with sub‐10 nm resolution on low‐pressure and submicron‐sized molds, compared with conventional imprinting processes. The generated nanostructures using reshaping process exhibit excellent surface Raman enhancement, enabling high‐sensitivity molecular detection. The reshaping strategy provides a novel strategy for the rapid, repeatable, and economical manufacturing of sharp nanostructures, which has broad application prospects in the fields of plasmonics and photonics.