Strain learning in protein-based mechanical metamaterials

• 成果类型: Article
• 署名作者: Sadaba, Naroa; Sanchez-Rexach, Eva; Waltmann, Curt; Hilburg, Shayna L.; Pozzo, Lilo D.; de la Cruz, Monica Olvera; Sardon, Haritz; Meza, Lucas R.; Nelson, Alshakim
• 署名单位: University of Washington; University of Washington Seattle; University of Basque Country; POLYMAT; University of Basque Country; Northwestern University; University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14371
• DOI: 10.1073/pnas.2407929121
• 发表日期: 2024-11-05
• 关键词: bovine serum-albumin; wolffs law; ph; nanoconfinement; strength

摘要

Mechanical deformation of polymer networks causes molecular-level motion and bond scission that ultimately lead to material failure. Mitigating this strain-induced loss in mechanical integrity is a significant challenge, especially in the development of active and shape-memory materials. We report the additive manufacturing of mechanical metamaterials made with a protein-based polymer that undergo a unique stiffening and strengthening behavior after shape recovery cycles. We utilize a bovine serum albumin-based polymer and show that cyclic tension and recovery experiments on the neat resin lead to a similar to 60% increase in the strength and stiffness of the material. This is attributed to the release of stored length in the protein mechanophores during plastic deformation that is preserved after the recovery cycle, thereby leading to a strain learning behavior. We perform compression experiments on three-dimensionally printed lattice metamaterials made from this protein-based polymer and find that, in certain lattices, the strain learning effect is not only preserved but amplified, causing up to a 2.5x increase in the stiffness of the recovered metamaterial. These protein-polymer strain learning meta-materials offer a unique platform for materials that can autonomously remodel after being deformed, mimicking the remodeling processes that occur in natural materials.