@misc{10481/107730,
year = {2025},
month = {11},
url = {https://hdl.handle.net/10481/107730},
abstract = {The high performance of biocomposites largely stems from their ability to self-organize. Our research on the
Pteria penguin reveals a hierarchical columnar calcitic (CC) microstructure essential to its mechanical properties.
Electron backscatter diffraction shows that each column constitutes a near-to-single-crystal composed of nanounits. Growth is stress-assisted, causing one-sided bending and considerable orientation differences between the
top and bottom of columns. The arising stresses are efficiently relaxed by using division along low-energy planes.
The detected phenomenon can underlie the branching process observed in more advanced microstructures
resulting from species’ adaptations over time. The stresses can also be reduced by the frequent formation of
unusual twins resembling intra-columnar flow zones. Using a custom program to detect crystal lattice matching
in reciprocal space reveals that a low-energy plane initiating a well-developed column is used by the neighbors,
forming coherence zones. Long-range hierarchical order is also supported by the organic matrix with hexagonal
channels, geometrically compatible with calcite crystals. Consequently, columns with the same orientation or in
twin relation, based on a 60◦ rotation around the c-axis, are formed in a direct neighborhood or at a distance. The
final biocomposite structure enables effective load transfer and crack suppression, achieving a notable
compressive strength of 670 MPa, despite being built from weak components. The developed programs for
identifying microstructural cohesion in crystalline materials allow the implementation of the discovered universal rules of hierarchical self-organization in 3D printing technology. This process can be enhanced by artificial
intelligence (AI)-accelerated multiscale simulations.},
organization = {Polish National Science Center - (UMO-2018/29/B/ST8/02200PID2020)},
organization = {MCIN/AEI/10.13039/501100011033, FEDER (PID2020-116660GB-I00, PID2023-146394NB-I00)},
organization = {Junta de Andalucía, Consejería de Economía, Innovación, Ciencia y Empleo - (PCM00092, RNM363)},
publisher = {Elsevier},
keywords = {Biocomposite},
keywords = {Mollusk shells},
keywords = {Organic matrix},
title = {Energy-driven microstructure and mechanical properties of mineral-organic biocomposite - Pteria penguin shell},
doi = {10.1016/j.matdes.2025.114948},
author = {Nalepka, Kinga and Berent, Katarzyna and Strag, Martyna and Checa González, Antonio G. and Petrzak, Paweł and Bieda, Magdalena and Sztwiertnia, Krzysztof},
}