Technique for 3-D Printing Metals at the Nanoscale Reveals Surprise Benefit
Late last year, Caltech researchers revealed that they had developed a new fabrication technique for printing microsized metal parts containing features about as thick as three or four sheets of paper. Now, the team has reinvented the technique to allow for printing objects a thousand times smaller: 150 nanometers, which is comparable to the size of a flu virus. In doing so, the team also discovered that the atomic arrangements within these objects are disordered, which would, at large scale, make these materials unusable because they would be considered weak and "low quality." In the case of nanosized metal objects, however, this atomic-level mess has the opposite effect: these parts can be three-to-five-times stronger than similarly sized structures with more orderly atomic arrangements.
The work was conducted in the lab of Julia R. Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering; and Fletcher Jones Foundation Director of the Kavli Nanoscience Institute. It is described in a paper appearing in the journal Nano Letters. [Caltech story]
Beaming Clean Energy From Space
Once considered science fiction, technology capable of collecting solar power in space and beaming it to Earth to provide a global supply of clean and affordable energy is moving closer to reality. Through the Space-based Solar Power Project (SSPP), a team of Caltech researchers is working to deploy a constellation of modular spacecraft that collect sunlight, transform it into electricity, then wirelessly transmit that electricity wherever it is needed—including to places that currently have no access to reliable power. "This is an extraordinary and unprecedented project," says Harry Atwater, Otis Booth Leadership Chair, Division of Engineering and Applied Science; Howard Hughes Professor of Applied Physics and Materials Science; Director, Liquid Sunlight Alliance. "It exemplifies the boldness and ambition needed to address one of the most significant challenges of our time, providing clean and affordable energy to the world." [Caltech story]
Mimicking Termites to Generate New Materials
Inspired by the way termites build their nests, researchers at Caltech have developed a framework to design new materials that mimic the fundamental rules hidden in nature's growth patterns. "We thought that by understanding how a termite contributes to the nest's fabrication, we could define simple rules for designing architected materials with unique mechanical properties," says Chiara Daraio, G. Bradford Jones Professor of Mechanical Engineering and Applied Physics; Investigator, Heritage Medical Research Institute. [Caltech story]