Limpet teeth microstructure unites auxeticity with extreme strength and high stiffness

Abstract

Materials displaying negative Poisson’s ratio, referred to as auxeticity, have been found in nature and created in engineering through various structural mechanisms. However, uniting auxeticity with high strength and high stiffness has been challenging. Here, combining in situ nanomechanical testing with microstructure-based modeling, we show that the leading part of limpet teeth successfully achieves this combination of properties through a unique microstructure consisting of an amorphous hydrated silica matrix embedded with bundles of single-crystal iron oxide hydroxide nanorods arranged in a pseudo-cholesteric pattern. During deformation, this microstructure allows local coordinated displacement and rotation of the nanorods, enabling auxetic behavior while maintaining one of the highest strengths among natural materials. These findings lay a foundation for designing biomimetic auxetic materials with extreme strength and high stiffness.

Biomimicry of Limpet Teeth with Hybrid Colloidal Liquid Crystals: Mechanical Enhancement by Structural Orderliness from Self-Assembly

“…Apparently, the interlayer spacing of aerogel decreased or even disappeared after hot-pressing treatment, and the ordered microstructure was preserved in the obtain composite laminate for a density of 2.07 ± 0.02 g/cm 3 (Figure 4F and Figure S6), which was beneficial to improve the mechanical properties of materials. Such large-scale aligned structure after being pressed would provide a possibility for this lightweight composite laminate to be used in special condition, where the ordered structure was required.…”

“…2 This unique microstructure unites strength, stiffness, toughness as well as auxeticity properties, making limpet teeth the strongest and hardest biological tissues ever discovered in nature. 3,4 The radula teeth of limpets are so strong and durable that these marine mollusks can use their teeth to scrape endolithic algae off intertidal rocks for food without damaging them. 5 The structure-function relationships in limpet teeth, like https://doi.org/10.26434/chemrxiv-2023-h5fdl ORCID: https://orcid.org/0000-0002-4585-9439 Content not peer-reviewed by ChemRxiv.…”

Guidelines derived from biomineralized tissues for design and construction of high-performance biomimetic materials: from weak to strong

“…Among various morphologies of biominerals, one-dimensional building blocks are common in BMTs, and they tend to orient along the longitudinal direction, forming fiber array structures, such as fiber bundles, 57,83 prismatic layers [253][254][255] and fiberboards. 256,257 At a higher level, they assemble into more complex hierarchical ordered structures, such as alignment, 101,258,259 staggering, 260,261 stack-up, 262 helices, 263 etc. As shown in Fig.…”

Biomimicry of Limpet Teeth with Colloidal Liquid Crystals of Minerals and Polysaccharides

“…The radula teeth of the common limpet (Patella vulgata), consisting of orderly aligned hard goethite (alpha-FeOOH) nanofibers incorporated within soft and continuous chitin matrices . This unique microstructure unites strength, stiffness, toughness as well as auxeticity properties, making limpet teeth the strongest and hardest biological tissues ever discovered in nature. , The radula teeth of limpets are so strong and durable that these marine mollusks can use their teeth to scrape endolithic algae off intertidal rocks for food without damaging them . The structure–function relationships in limpet teeth, like those found in many other biological tissues, − may help to improve the mechanical performances of composite materials.…”