Design across hierarchy: morphological and mechanical insights into pili nuts (Canarium ovatum)
Year: 2025
Type: article
Abstract: In recent years, the biomimetic potential of hard nutshells has gained increasing attention. For transferring functional principles into bio-inspired applications, a detailed understanding of the structural composition of these natural models is essential. The aim of this study is to investigate the hierarchical functional morphology of the pili nut (Canarium ovatum) and link it to its mechanical properties across multiple length scales. We distinguish eight hierarchical levels (H) for the entire fruit, comprising structural features on the organ (H0–H2), tissue (H3), cellular (H4), sub-cellular (H5–H6), and molecular levels (H7) using a combination of various imaging techniques. Emphasis is placed on the endocarp (H3–H6). On the microscale, the endocarp fails in a brittle manner, with cracks propagating straight through sclerenchymatous cells, without fiber pull-out, showing only minor deflections around the fibers. The brittle base material is organized in a sandwich structure with weak interfaces. By providing detailed morphological parameters at multiple hierarchical levels and describing their influence on fracture behavior, this study provides a first step toward understanding the microstructure of the pili nut endocarp, which may inform future biomimetic designs of robust materials.
Source: Materials & Design
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
OpenAlex ID: W4416416232