Ultrahigh Energy Absorption Multifunctional Spinodal Nanoarchitectures

Abstract

Nanolattices are promoted as next‐generation multifunctional high‐performance materials, but their mechanical response is limited to extreme strength yet brittleness, or extreme deformability but low strength and stiffness. Ideal impact protection systems require high‐stress plateaus over long deformation ranges to maximize energy absorption. Here, glassy carbon nanospinodals, i.e., nanoarchitectures with spinodal shell topology, combining ultrahigh energy absorption and exceptional strength and stiffness at low weight are presented. Noncatastrophic deformation up to 80% strain, and energy absorption up to one order of magnitude higher than for other nano‐, micro‐, macro‐architectures and solids, and state‐of‐the‐art impact protection structures are shown. At the same time, the strength and stiffness are on par with the most advanced yet brittle nanolattices, demonstrating true multifunctionality. Finite element simulations show that optimized shell thickness‐to‐curvature‐radius ratios suppress catastrophic failure by impeding propagation of dangerously oriented cracks. In contrast to most micro‐ and nano‐architected materials, spinodal architectures may be easily manufacturable on an industrial scale, and may become the next generation of superior cellular materials for structural applications.

Plate-nanolattices at the theoretical limit of stiffness and strength

“…With average compressive strength and stiffness improvements up to 639% and 522%, respectively, compared to the best beam-nanolattices 6,23 , our plate-nanolattices are the only reported materials to lie at the theoretical compressive strength limits and the only architected material to exceed synthetic macroscale cellular materials, like ceramic foams 25 , in stiffness, thus representing the strongest and stiffest existing architected materials to date. Figure 6 compares the compressive strength and stiffness data from this work with those of other architected and bulk materials [6][7][8][9][10][11][12]16,23,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] . The theoretical limits 1,6,23 are taken as regions bounded by a linear scaling of graphene (the strongest and stiffest known material, albeit in two dimensions and at the nanoscale) and bulk diamond (the strongest and stiffest bulk material at the macroscale).…”

“…3). In previous work, highly curved, thin shell topologies made of brittle constituent materials, such as pyrolytic carbon, have been shown to exhibit progressive failure with high stress plateaus up to 80% strain 45 . This behavior arises from an advantageous crack propagation mechanism displayed by shells with high radius of curvature-to-thickness ratios.…”

Pushing and Pulling on Ropes: Hierarchical Woven Materials

“…[ 18,22 ] These materials are appealing in a number of applications where maximal linear mechanical properties are required, but lose their optimality in large deformations due to their failure mechanisms and constrained kinematics. In particular, few architected materials made of materials stiffer than elastomers have been reported to withstand deformations greater than 20% strain, [ 23,24 ] and most of them fail catastrophically or accumulate significant damage. [ 11,25–27 ] The geometries in these materials lead to stress concentration at junctions or nodes where damage nucleates, [ 11,28,29 ] commonly resulting in significantly weaker or compliant responses after the initial deformation.…”

“…While higher stiffness‐ and strength‐to‐weight ratios can be achieved by choosing closed‐cell, plate‐based designs over beam‐and‐junction‐based designs, the deformability of such architected materials is still limited. [ 30–32 ] As an alternative, architected materials that lack junctions or nodes, such as triply periodic minimal surface and stochastic spinodal shell designs, [ 24,33–35 ] more evenly distribute stresses throughout their components but have not yet enabled repeatable large deformations without significant degradation except for designs with very low material fill fraction. [ 36 ] Wire‐woven architected materials have recently been reported to have desirable energy absorption capabilities and buckling suppression, [ 37,38 ] presenting a potential approach to enable repeatable deformability, but have lacked the introduction of hierarchy to further enhance these properties.…”

3D-printed cellular tips for tuning fork atomic force microscopy in shear mode

“…As a succession to natural instances in motion deceleration, shockwave suppression, and mechanical force reduction 14 , porous structures widely found in biological skeletal systems such as cancellous bones have been extensively investigated in numerous energy-absorbing applications [15][16][17][18] . Emulating these geometrical constructions and coupling with advanced additive manufacturing techniques in microscale, artificial cellular microarchitectures, referred to as controlled microstructural architectured (CMA) material [19][20][21] , can be structurally programmed with a controllable geometry and spatial configuration for advantageous sizedependent metamechanical properties 22,23 , such as low density but strong robustness 24 , high stiffness-to-weight ratio 25 , excellent resilience 26,27 , mechanical tunability 28,29 , and in particular, energy absorption [30][31][32][33] . Hence, by employing this cellular hierarchy for the geometric design of the tip itself, the tip-sample interaction is anticipated to be reduced.…”