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arXiv · 2010.08170

Hyperspectral interference tomography of nacre

Jad Salman·Cayla A. Stifler·Alireza Shahsafi·Chang-Yu Sun·Steve Weibel·Michel Frising·Bryan E. Rubio-Perez·Yuzhe Xiao·Christopher Draves·Raymond A. Wambold·Zhaoning Yu·Daniel C. Bradley·Gabor Kemeny·Pupa U. P. A. Gilbert·Mikhail A. Kats
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Abstract

Structural characterization of biologically formed materials is essential for understanding biological phenomena and their environment, and generating new bio-inspired engineering concepts. For example, nacre -- formed by mollusks in the ocean -- encodes local environmental conditions throughout its formation and has exceptional strength due to its nanoscale brick-and-mortar structure. This layered structure, comprising transparent aragonite tablets bonded with an ultra-thin organic polymer, also results in stunning interference colors. Existing methods of structural characterization of nacre rely on some form of cross-sectional analysis, such as scanning electron microscopy or polarization-dependent imaging contrast (PIC) mapping. However, these techniques are destructive and too time- and resource-intensive to analyze large sample areas. Here we present an all-optical, rapid, and non-destructive imaging technique -- hyperspectral interference tomography (HIT) -- to spatially map the structural parameters of nacre and other disordered layered materials. We combined hyperspectral imaging with optical-interference modeling to infer the mean tablet thickness and disordering of nacre layers across entire mollusk shells at various stages of development, observing a previously unknown relationship between the growth of the mollusk and tablet thickness. Our rapid, inexpensive, and nondestructive method can be readily applied to in-field studies.

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BibTeXRIS

Jad Salman, Cayla A. Stifler, Alireza Shahsafi, Chang-Yu Sun, Steve Weibel, Michel Frising, Bryan E. Rubio-Perez, Yuzhe Xiao, Christopher Draves, Raymond A. Wambold, Zhaoning Yu, Daniel C. Bradley, Gabor Kemeny, Pupa U. P. A. Gilbert, Mikhail A. Kats. 2020-10-16. Hyperspectral interference tomography of nacre. https://doi.org/10.1073/pnas.2023623118

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