Materials by Design: 3-Dimensional Nano-Architected Meta-Materials

Creation of extremely strong yet ultra-light materials can be achieved by capitalizing on the hierarchical design of 3-dimensional nano-architectures. Such structural meta- materials exhibit superior thermal, photonic, electrochemical, and mechanical proper- ties at extremely low mass densities (lighter than aerogels), rendering them ideal for many scientific and technological applications. The dominant properties of such “meta-materials”, where individual constituent size (atoms to nanometers to microns) is comparable to the characteristic microstructural length  scale  of  the  constituent solid, are largely unknown because of their truly multi-scale nature. To harness the beneficial properties of 3-dimensional nano-architecter meta-materials, it is critical to assess properties at each relevant scale while capturing the overall structural complexity.

We fabricate 3-dimensional nano-architectures (i.e. nanolattices) whose constituents vary in size from several nanometers to tens of microns to millimeters and centimeters. We discuss the deformation, as well as mechanical, chemical, and photonic properties of a range of nano-sized solids with different microstructures deformed in an in-situ nanomechanical instrument. Attention is focused on the interplay between the internal critical  microstructural  length  scale  of  materials  and their external limitations in revealing the physical mechanisms that govern these properties, where competing material- and structure-induced size effects drive overall response.

Specific discussion topics include: fabrication and characterization of (often hierarchical) 3-dimensional nano-architected meta-materials for applications  in chemical and biological sensors, ultra lightweight energy storage systems, damage- tolerant fabrics, and photonic crystals.

Some Relevant publications:

1. L. R. Meza, S. Das, J. R. Greer “Strong, Lightweight and Recoverable Three- Dimensional Ceramic Nanolattices” Science 345, 1322-1326 (2014)
2. J.R. Greer “Materials by design: Using architecture and nanomaterial size effects to attain unexplored properties.” Nat’l Acad. of Engineering’s Bridge 45(4) (2015)
3. L. Meza, et al., J.R. Greer “Hierarchy in 3-D Architected Meta-Materials Brings Resilience” Proc of the Nat’l Academy of Sciences 112 (37), 11502 (2015)
4. X. Xia, C. V. Di Leo, X. W. Gu, A. Lozano, J. R. Greer “In Situ  Lithiation– Delithiation of Mechanically Robust Cu–Si Core–Shell Nanolattices in a Scanning Electron Microscope” ACS Energy Letters 1, 492–499 (2016)
5. Montemayor, L. C., Wong, W. H., Zhang, Y.-W.,  Greer,  J.  R.  “Insensitivity  to Flaws Leads to Damage Tolerance in  Brittle  Architected  Meta-Materials” Scientific Reports, 6, 20570 (2016)
6. V. Chernow, H. Alaeian, J. Dionne, J.R. Greer “"Polymer Nanolattices as Mechanically Tunable 3-Dimensional Photonic Crystals" Appl. Phys. Lett 107, 101905 (2015)
7. C. Xu, B. M. Gallant, P. U. Wunderlich, T. Lohmann, J. R. Greer “3-Dimensional Au microlattices as cathodes for Li-O2 batteries” ACS Nano 9 (6), 5876–5883 (2015)