Unwinding a spiral of cellulose nanocrystals for stimuli-responsive stretchable optics.

ABSTRACT: Cellulose nanocrystals (CNCs) derived from biomass spontaneously organize into a helical arrangement, termed a chiral nematic structure. This structure mimics the organization of chitin found in the exoskeletons of arthropods, where it contributes to their remarkable mechanical strength. Here, we demonstrate a photonic sensory mechanism based on the reversible unwinding of chiral nematic CNCs embedded in an elastomer, leading the materials to display stimuli-responsive stretchable optics. Vivid interference colors appear as the film is stretched and disappear when the elastomer returns to its original shape. This reversible optical effect is caused by a mechanically-induced transition of the CNCs between a chiral nematic and pseudo-nematic arrangement.

SUBMITTER: Kose O 

PROVIDER: S-EPMC6355765 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature