Nano-architectured materials were first designed by Caltech’s material scientist, Julie R. Greer and can be used for a variety of applications such as making advanced lightweight batteries. The structures of these materials are designed at such a small scale that they often have to be assembled by nano-layer after nano-layer in a 3-D printing process that might take months for a small prototype to complete. Since this process takes a long time, it limits the overall amount of material that can possibly be built.
To tackle this problem, engineers at Caltech and ETH Zurich have developed a material that is designed at nanometer scale like the nano-architectured materials however, it assembles itself indicating that assembly through a precision laser is no longer required. At the nanoscale, the material is an assembly of interconnected curved shells. Since the material is composed of smoothly curved thin shells, it is free of corners or junctions so it does not have any weak points where it could break or bend, making it a material with high-stiffness and strength-to-weight ratios. After carrying out numerous tests, scientists were able to achieve strength-to-weight ratios comparable to some forms of steel which emphasized the potential of durability and strength of the material.
This nano-labyrinthine material is made by mixing and blending two materials that do not dissolve into each other; this creates a disordered state between them. Next, heating up the mixture polymerizes the material so that the geometry is locked into one place. One of the two materials is then removed which leaves nano-scale shells. These nano-scale shells are coated to lock them in place and then the second polymer is removed from the structure leaving a lightweight nano-shell network. While this process is significantly less time consuming and more effective than 3-D printing the structures, it requires extreme precision. If the initial mixture of materials is incorrectly heated, the microstructure might melt altogether or collapse entirely.
Knowing the potential of this material, scientists plan to expand the versatility of the process by exploring different ways to expand the material options, carefully control the microstructure and produce large volumes of the material.
Microstructures Self-Assemble into New Materials: