Chiral nanomaterials have attained great attentions for their unique optical, magnetic, and catalytic characteristics. However, their practical applications are often hindered by the high costs associated with conventional fabrication techniques, such as sophisticated lithography and wet chemical synthesis. To overcome this limit, this presentation presents a simple and straightforward method that harnesses biaxial and asymmetric strain-induced buckling to generate twisted wrinkle structures for mirror-symmetric chiral geometries. For their fabrications, polydimethylsiloxane (PDMS) substrates are stretched asymmetrically in different directions. Subsequently, these substrates undergo ozone or oxygen plasma treatment, leading to the formation of hard oxide layers. By releasing in-plane strains, twisted, fusilli pasta-like wrinkle structures are obtained. These particular geometries can be precisely manipulated by controls of the buckling process. These chiral structures can be further modified by coatings of plasmonic nanoparticles or selective depositions of gold films to show tunable chiroptical responses in a desired frequency range. The ability to control chiral geometries promotes particular performances in chiral field enhancements, which facilitates enhanced chiroptical responses in circular dichroism signals of enantiomers for potential applications to bio-sensing platforms.
