Plate-nanolattices at the theoretical limit of stiffness and strength

Abstract

Though beam-based lattices have dominated mechanical metamaterials for the past two decades, low structural efficiency limits their performance to fractions of the Hashin-Shtrikman and Suquet upper bounds, i.e. the theoretical stiffness and strength limits of any isotropic cellular topology, respectively. While plate-based designs are predicted to reach the upper bounds, experimental verification has remained elusive due to significant manufacturing challenges. Here, we present a new class of nanolattices, constructed from closedcell plate-architectures. Carbon plate-nanolattices are fabricated via two-photon lithography and pyrolysis and shown to reach the Hashin-Shtrikman and Suquet upper bounds, via in situ mechanical compression, nano-computed tomography and micro-Raman spectroscopy. Demonstrating specific strengths surpassing those of bulk diamond and average performance improvements up to 639% over the best beam-nanolattices, this study provides detailed experimental evidence of plate architectures as a superior mechanical metamaterial topology.

Tensegrity Metamaterials: Toward Failure‐Resistant Engineering Systems through Delocalized Deformation

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Pushing and Pulling on Ropes: Hierarchical Woven Materials

“…achieved by choosing closed-cell, plate-based designs over beamand-junction-based designs, the deformability of such architected materials is still limited. [30][31][32] As an alternative, architected materials that lack junctions or nodes, such as triply periodic minimal surface and stochastic spinodal shell designs, [24,[33][34][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.…”

Understanding the Electrical Behavior of Pyrolyzed Three‐Dimensional‐Printed Microdevices

“…[ 14 ] These studies focus on the ability to create some of the strongest known devices, approaching a theoretical strength limit. [ 15–17 ] There have also been developments in the creation of carbon MEMS devices out of the 2PP photoresist pyrolyzed carbon material, [ 18,19 ] taking advantage of the electrical conductivity of glassy carbon. Despite studies being done on the manufacturing of electrical devices with carbon materials derived from 2PP photoresists, little has been done to characterize the material's microstructure and electrical properties, with only one study on the microstructural characterization of the material.…”