Lamellibrachia tubeworm tube as a model tissue for the investigation of β-chitin piezoelectric properties
A. Burg1, JF. Capsal2, Y. Ogawa3 & M. Fumagalli1
1 IMP Lab, Univ. Lyon, 15 bd Latarjet, F-69622, Villeurbanne, France
2 LGEF Lab, INSA Lyon, 8 rue de la Physique, 69621, Villeurbanne, France
3 CERMAV Lab, CNRS, Univ. Grenoble, F-38000 Grenoble, France
Cellulose and chitin are the most abundant biomass (hundreds of Gt/yr) and are found in plant, algae and fungus cell walls and in arthropod exoskeletons. Those polysaccharides are biosynthesized in the form of crystalline microfibrils having a non centrosymmetric and polar structure which makes them attractive building blocks for electro-active devices. Yet, little is known about the intrinsic electro-mechanical features of such materials,  mostly because the hierarchical architecture of most of the biological materials is unadequate to observe a large macroscopic polarization.
In this context, we investigated the piezoelectric properties of β-chitin from Lamellibrachia tubeworm tube. Such model biological material is constituted of a β-chitin microfibrils load bearing network within which all the crystalline lattices are oriented with the same polarity along the tube axis.  This unique feature is determinant to obtain a significant macroscopic piezoelectric behavior. We performed mechanical, dielectrical and direct piezoelectric measurements onto the native tube and onto materials obtained after extracting the constitutive β-chitin network. We also characterized the materials microstructure through electron microscopy and WAXS. We will further discuss how such macroscopic measurements are related to the behavior of a single β-chitin crystallite.
 Chae, I., Jeong, C. K., Ounaies, Z., & Kim, S. H. (2018). Review on electromechanical coupling properties of biomaterials. ACS Applied Bio Materials, 1(4), 936-953.
 Ogawa, Y., Kobayashi, K., Kimura, S., Nishiyama, Y., Wada, M., & Kuga, S. (2013). X-ray texture analysis indicates downward spinning of chitin microfibrils in tubeworm tube. Journal of structural biology, 184(2), 212.