Strong, lightweight, and recoverable three-dimensional ceramic nanolattices

Abstract

Ceramics have some of the highest strength- and stiffness-to-weight ratios of any material but are suboptimal for use as structural materials because of their brittleness and sensitivity to flaws. We demonstrate the creation of structural metamaterials composed of nanoscale ceramics that are simultaneously ultralight, strong, and energy-absorbing and can recover their original shape after compressions in excess of 50% strain. Hollow-tube alumina nanolattices were fabricated using two-photon lithography, atomic layer deposition, and oxygen plasma etching. Structures were made with wall thicknesses of 5 to 60 nanometers and densities of 6.3 to 258 kilograms per cubic meter. Compression experiments revealed that optimizing the wall thickness-to-radius ratio of the tubes can suppress brittle fracture in the constituent solid in favor of elastic shell buckling, resulting in ductile-like deformation and recoverability.

Bottom-up Design of Three-Dimensional Carbon-Honeycomb with Superb Specific Strength and High Thermal Conductivity

“…One of the important feature of C-honeycomb is its ultra-light weight with tunable cell sizes that may be employed as electrodes for batteries with ultrafast charge and discharge rates 37 , flexible supercapacitor electrodes 38 , and storage media 39 . The density 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 15 of C-honeycombs with ܽ = 5.8Å to 29.7Å are only 1.31 g/cm 3 to 0.31 g/cm 3 , much lower than 3.52 g/cm 3 for diamond and 2.26 g/cm 3 for graphite 40 .The high specific strength of 3-D C-honeycomb render it extremely competitive for the use as an ultra-light weight architected functional material 41 . …”

“…The density 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 15 of C-honeycombs with ܽ = 5.8Å to 29.7Å are only 1.31 g/cm 3 to 0.31 g/cm 3 , much lower than 3.52 g/cm 3 for diamond and 2.26 g/cm 3 for graphite 40 .The high specific strength of 3-D C-honeycomb render it extremely competitive for the use as an ultra-light weight architected functional material 41 . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 ...…”

On the Use of Mechanical Metamaterials for Innovative Seismic Isolations Systems

“…These may include: exceptional strength-and stiffness-to-weight ratios; excellent strain recoverability; very soft and/or very stiff deformation modes; auxetic behavior; phononic bandgaps; sound control ability; negative effective mass density; negative effective stiffness; negative effective refraction index; superlens behavior; and/or localized confined waves, to name some examples (cf. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and references therein). The category of "extremal materials" has been introduced in [3] to define materials that simultaneously show very soft and very stiff deformation modes (unimode, bimode, trimode, quadramode and pentamode materials, depending on the number of soft modes).…”

Super-carbon spring: a biomimetic design

“…Dan Li * and Ling Qiu Low-density cellular materials with high compressibility, elasticity and fatigue resistance hold promise for applications in mechanical damping, flexible electronics, actuators and multifunctional polymer nanocomposites [1][2][3][4][5]. Recently, cellular materials with ultralow density and superelasticity have been successfully synthesized with robust and flexible nanoscale building blocks such as graphene and carbon nanotubes [6][7][8][9].…”

“…Recently, cellular materials with ultralow density and superelasticity have been successfully synthesized with robust and flexible nanoscale building blocks such as graphene and carbon nanotubes [6][7][8][9]. However, when these cellular materials undergo large strain cyclic compression, microstructure cracking or buckling failure often occurs, leading to large energy dissipation, plastic deformation and reduction of strength [1,2,6]. As the mechanical properties of a cellular material are dependent on not only the mechanical attributes of the basic building blocks, but also the hierarchical structure of the assembled cellular network, it has been very challenging to find an effective solution to synthesize a cellular material with combined high compressibility, elasticity and fatigue resistance.…”