Nanohelicoid metamaterials templated by cellulose nanocrystals with end-tethered polymers

Introduction

Chirality plays a fundamental role in natural sciences and pharmacology. The ability to detect chiral molecules relies heavily on inherently weak circularly polarized light-matter interactions. Such interactions are enhanced in the presence of chiral metamaterials, which exhibit extraordinary electromagnetic properties not observed in nature.

Current Challenges

To date, large and broadband circular dichroism in the UV-visible spectrum requires arrays of metallic nanohelices in order to combine internal and Bragg resonances. However, their fabrication relies on costly electron/ion beam lithography or physical vapor deposition, in which it is difficult and time-consuming to control nanoscale morphology over large areas.

Need for Innovation

New types of helix metamaterials and engineering processes based on self-assembly concepts are absolutely necessary in order to be viable for future technologies. Nevertheless, self-assembled metamaterials with large, broadband, and tunable chiroptical responses in the UV-visible region is a great challenge due to the required subwavelength feature sizes.

Proposed Solution

To this end, the helicoidal morphologies of chiral liquid crystals provide the ideal platform for maximizing chiral light-matter interactions. The objective of CELICOIDS is to investigate the use of the chiral liquid crystal phases of cellulose nanocrystals with end-tethered polyoxyethylene analogues as templates for the fabrication of a new class of metamaterial, solid metallic nanohelicoids.

Recent Breakthrough

A recent breakthrough that now makes this project possible is the discovery that such cellulose nanocrystal hybrids form chiral liquid crystal phases. As one of the very few researchers in the world with the combined expertise in cellulose chemistry, polymer grafting, and colloidal assembly, I am the ideal candidate to achieve success.

Future Applications

New functionalities are envisioned thereafter, applicable to future devices for invisibility cloaking, super-resolution imaging, and chiral sensing, prompting a change in paradigm in metamaterials.