Nanolattices have the potential to increase strength to weight by one million times but massively scaling production is the main hurdle

If nanolattice material could be produced in large quantities, they could replace composites and other materials used in a wide range of applications, because they’d be just as strong at a fraction of the weight. Another possibility is to greatly increase the energy density of batteries—the amount of power they can hold at a given size.

So far, they can’t make enough of the nanostructured materials to cover your palm. MIT Technology Review thinks that the production breakthroughs could happen by 2020 for the initial commercialization applications.

Some recent publications:

Extreme Mechanics Letters – Ultra-strong architected Cu meso-lattices

Abstract -Ultra-strong architected Cu meso-lattices

3-dimensional solid Cu octet meso-lattices with characteristic features on the micron-scale were fabricated and mechanically tested under uniaxial compression. These architected cellular materials were fabricated by a three-step process: (1) direct laser writing of the lattice pattern into a polymer template, (2) electroplating of Cu into the template, and (3) removal of the polymer matrix. The microstructure of the electroplated Cu mainly consists of polycrystalline grains with average diameters of such that cross-sections of lattice beams mostly consist of a single grain. We discovered that the compressive yield strengths of the open-cell Cu meso-lattices can exceed the yield strength of monolithic bulk Cu as measured from a Cu thin film made with identical conditions. Meso-lattices with relative density of 0.8 had a strength of 332 MPa, which surpassed the bulk yield strength by 80%. This is diametrically opposite to predictions from structural mechanics theory, which states that strength scales linearly with relative density for the octet structure. We attribute the ability of solid Cu meso-lattices to attain such high strengths to the “smaller is stronger” size effect present in single crystalline metals with sub-micron dimensions. This work demonstrates the use and proliferation of the size-dependent strengthening unique to nanostructures in an architected structural material.

Applied Physics Letters – Ductility and work hardening in nano-sized metallic glasses

A mastery of engineered hierarchy in material microstructures might one day allow us to make ductile metallic glasses that both deform and harden like steels and possess superior strength and stiffness.

Journal of the Mechanics and Physics of Solids – The effect of size, orientation and alloying on the deformation of AZ31 nanopillars

Nextbigfuture has been covering the work since 2013

Nanometer thick walls that are made into hollow trusses to enable far lighter and stronger material.

Julia Greer’s web page at Cal Tech

Journal of Materials Science – Mechanical characterization of hollow ceramic nanolattices

A talk was given at a local TEDx event, produced independently of the TED Conferences (TEDx CERN). Imagine being able to hold all the material it took to build an airplane in the palm of your hand. Julia Greer combines different design structures at varying nano-scales to create super strong and super light materials. Her research is changing the landscape of materials available today.

Julia Greer researches lightweight, 3-dimensional nano-architectures and designs experiments to assess their properties and deformation mechanisms. These ‘nano-metamaterials’ have multiple applications, which provide a rich ‘playground’ for fundamental scientific pursuits.

Abstract

In the analysis of complex, hierarchical structural meta-materials, it is critical to understand the mechanical behavior at each level of hierarchy in order to understand the bulk material response. We report the fabrication and mechanical deformation of hierarchical hollow tube lattice structures with features ranging from 10 nm to 100 μm, hereby referred to as nanolattices. Titanium nitride (TiN) nanolattices were fabricated using a combination of two-photon lithography, direct laser writing, and atomic layer deposition. The structure was composed of a series of tessellated regular octahedra attached at their vertices. In situ uniaxial compression experiments performed in combination with finite element analysis on individual unit cells revealed that the TiN was able to withstand tensile stresses of 1.75 GPa under monotonic loading and of up to 1.7 GPa under cyclic loading without failure. During the compression of the unit cell, the beams bifurcated via lateral-torsional buckling, which gave rise to a hyperelastic behavior in the load–displacement data. During the compression of the full nanolattice, the structure collapsed catastrophically at a high strength and modulus that agreed well with classical cellular solid scaling laws given the low relative density of 1.36 %. We discuss the compressive behavior and mechanical analysis of the unit cell of these hollow TiN nanolattices in the context of finite element analysis in combination with classical buckling laws, and the behavior of the full structure in the context of classical scaling laws of cellular solids coupled with enhanced nanoscale material properties.

Nature Materials – Fabrication and deformation of three-dimensional hollow ceramic nanostructures

Advanced Engineering Materials – Design and Fabrication of Hollow Rigid Nanolattices via Two-Photon Lithography

This paper presents the design and fabrication of 3-dimensional hollow metallic nanolattices using 2-photon lithography. The ability to fabricate structures of any geometry, with resolution down to 150 nm, provides opportunities to engineer structures spanning multiple length scales with potential to capitalize on combined structural and material size effects for use in many technological applications.

Nextbigfuture covered earlier publications of this work in Sept of 2013

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