Ognjen Ilic, postdoctoral scholar in Professor Harry Atwater’s laboratory, and colleagues have designed a way to levitate and propel objects using only light, by creating specific nanoscale patterning on the objects' surfaces. "We have come up with a method that could levitate macroscopic objects," says Professor Atwater, who is also the director of the Joint Center for Artificial Photosynthesis. "There is an audaciously interesting application to use this technique as a means for propulsion of a new generation of spacecraft. We're a long way from actually doing that, but we are in the process of testing out the principles." [Caltech story]
Julia Greer, Professor of Materials Science, Mechanics and Medical Engineering, and colleagues have determined that the failure of architected materials—the point at which they break when compressed or stretched—can be described using classical continuum mechanics, which models the behavior of a material as a continuous mass rather than as individual (or "discrete") particles. This finding implies a duality to the nature of these materials—in that they can be thought of both as individual particles and also as a single collective. [Caltech story]
Translational technology developed in Professor Harry A. Atwater’s laboratory seeks to improve the efficiency of solar panels by tweaking the architecture of the metal-grid layout of individual cells. The new startup company—ETC Solar, LLC—which is marketing the technology, took first place at the DOE's 2018 Cleantech University Prize national collegiate business plan competition in Houston. "To have been selected as a winner is a huge point of validation for the concept, both the innovation and also the impact," says Professor Atwater, who is also a co-founder of ETC Solar along with Thomas Russell, and Rebecca Saive. "It has helped us to make contacts with potential industrial partners and private equity investors," [Caltech story]
EAS Professors were among a small group of Caltech scientists and engineering who have won federal grants for research in quantum computing, and quantum networks. Professor Nadj-Perge (lead PI) along with co-PIs Professors Marco Bernardi and Andrei Faraon as well as co-investigator Professor Julia Greer have received funding for the program ”Quantum States in Layered Heterostructures Controlled by Electrostatic Fields and Strain," which is administered within the U.S. Department of Energy's Basic Energy Sciences division. Professor Austin Minnich is a co-PI of the program, "Quantum simulation of materials and molecules using quantum computation," which is part of the National Science Foundation's Research Advanced by Interdisciplinary Science and Engineering (RAISE)-Transformational Advances in Quantum Systems (TAQS) effort. [Caltech story]
Marco Bernardi, Assistant Professor of Applied Physics and Materials Science, has teamed up with physics colleague Professor David Hsieh, to offers new insight into a promising solar cell material called perovskites. "Despite being a relatively new technology, perovskite solar cells are now almost as efficient as solar cell materials that have been around for decades. But we still don't know why perovskite solar cells work so well," says Professor Bernardi, [Caltech story]
Professor Kerry J. Vahala and colleagues have developed a prototype of a miniature device that synthesizes frequencies on demand with about 1 Hertz accuracy. It combines a frequency comb developed at the National Institute of Standards and Technology (NIST) with a "fine-toothed" frequency comb developed at Caltech. To create the finely spaced comb teeth, the Caltech resonator must be about 100 times larger than the NIST device. Its larger size can potentially make this comb very power hungry. "Too much power in a small space can damage any electronics to which the resonator is connected," Professor Vahala says. "Also, in the future, these synthesizer devices could operate on battery power in smartphone-sized devices where they cannot draw much power." But the Caltech comb can generate specific frequencies with minimal amounts of power. [Caltech story]
Professor Harry A. Atwater, Jr. is an advisor to a multi-disciplinary $100-million project aimed at designing a spacecraft that can be launched to planets surrounding other stars and reach them within our lifetime. The Breakthrough Starshot Program has three big technical challenges: The first is to build the so-called photon engine, the laser that's capable of propelling the sail; the second is to design the sail itself; and the third is to design the payload, which will be a tiny spacecraft capable of taking images and spectral data and then beaming them back to the earth. Professor Atwater’s role is to help the program define pathways to making a viable lightsail that's compatible with the other objectives of the whole program. [Caltech story]
Most materials expand when heated. At temperatures below room temperature, silicon shows the opposite behavior, shrinking as it is heated. Even at room temperature the normal thermal expansion of silicon is rather small. A team led by Professor Brent Fultz wanted to know why, and found that the unusual property is the result of quantum effects coupled by the nonlinear forces between atoms in silicon. [Read the paper]
Postdoctoral scholar Nathan Belliveau working in the laboratory of Professor Rob Phillips has applied a method called Sort-Seq to mutate small pieces of noncoding regions in E. coli and determined which regions contain binding sites. Binding sites are the locations where specialized proteins that are involved in transcription—the first step in the process of gene expression—attach to DNA. "Humans have such a wide variety of cells—muscle cells, neurons, photoreceptors, blood cells, to name a few," says Professor Phillips. "They all have the same DNA, so how do they each turn out so differently? The answer lies in the fact that genes can be regulated—turned on or off, dialed up and dialed down—differently in different tissues. Until now, there have been no general principles to help us understand how this regulation was encoded." [Caltech story]
Professor Julia Greer and graduate student Andrey Vyatskikh have created complex nanoscale metal structures using 3-D printing. The process, once scaled up, could be used in a wide variety of applications and opens the door to the creation of a new class of materials with unusual properties that are based on their internal structure. [Caltech story]
