Department of Applied Physics and Materials Science - Applied Physics

News & Events


Microscopic Devices That Control Vibrations Could Allow Smaller Mobile Devices


Chiara Daraio, Professor of Mechanical Engineering and Applied Physics, and colleagues have developed phononic devices that include parts that vibrate extremely fast, moving back and forth up to tens of millions of times per second. The devices were developed by creating silicon nitride drums that are just 90 nanometers thick. The drums are arranged into grids, with different grid patterns having different properties. Professor Daraio, along with former Caltech postdoctoral scholar Jinwoong Cha, have shown that arrays of these drums can act as tunable filters for signals of different frequencies and can act like one-way valves for high-frequency waves. [Caltech story]

Tags: research highlights Chiara Daraio MCE APh postdocs Jinwoong Cha

President Rosenbaum Highlights Postdocs as "Unsung Heroes"


In a letter to the Caltech community during National Postdoc Appreciation Week, the Caltech President emphasizes the role this key group plays at the Institute. He stated, “Caltech's mission of world-leading research and education depends crucially on our postdoctoral scholars. Although their time at Caltech may be short, they quickly become vital parts of the Institute's intellectual fabric.” [President’s Letter] [EAS Postdoc Resource Page]

Tags: APhMS EE GALCIT MedE MCE CMS ESE Thomas Rosenbaum postdocs

No Motor, No Battery, No Problem


Chiara Daraio, Professor of Mechanical Engineering and Applied Physics, and colleagues have developed robots capable of self-propulsion without using any motors, servos, or power supply. Instead, these first-of-their-kind devices paddle through water as the material they are constructed from deforms with temperature changes. "Combining simple motions together, we were able to embed programming into the material to carry out a sequence of complex behaviors," says Caltech postdoctoral scholar Osama R. Bilal, who is co-first author of the PNAS paper is titled "Harnessing bistability for directional propulsion of soft, untethered robots." [Caltech story]

Tags: research highlights Chiara Daraio MCE APh postdocs Osama Bilal

Solving Pieces of the Genetic Puzzle


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]

Tags: research highlights Rob Phillips APh postdocs Nathan Belliveau

Postdoctoral Scholar Receives Dissertation Award From American Physical Society


Moureen C. Kemei, Resnick Sustainability Institute Prize Postdoctoral Scholar in Applied Physics & Materials Science, has recieved the American Physical Society's Richard L. Green Dissertation Award in Experimental Condensed Matter or Condensed Matter Physics. The award recognizes her outstanding thesis on "Magnetostructural and Magnetodielectric Coupling in Spinel Oxides" citing her achievement in employing advanced characterization tools to gain new insights into the structure and electronic properties of magnetic materials and solid oxide fuel cell (SOFC) cathode materials. The exploration of SOFC cathode materials is the focus of Moureen’s research at the Resnick Sustianability Institute, which she works on in the lab of Professor Sossina Haile. [Dr. Kemei’s Dissertation]

Tags: APhMS honors energy Sossina Haile Moureen Kemei postdocs

Former Caltech Postdoc Receives Israel Prize


Mordechai (Moti) Segev, a former postdoctoral fellow in Professor Amnon Yariv's group, will be receiving the Israel Prize for Physics and Chemistry. Dr. Segev is receiving the prize for ground-breaking research in the field of optics and lasers. "I am naturally proud of the achievements of former students and postdocs who started their scientific career in my group," says Professor Yariv. "Among this group Moti has become, in the relatively short time since leaving us, one the best known and influential scientists in the world in the field of quantum electronics and its amazing offspring of nonlinear optics. I am looking forward to a continuing stream of intellectual and experimental innovation flowing from him and his research group at the Technion."

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Tags: Amnon Yariv APhMS honors energy research highlights Moti Segev postdocs

Dr. Davenport Receives Award in Energy Efficiency and Renewable Energy


Timothy C. Davenport, Postdoctoral Scholar in Applied Physics and Materials Science, working with Professor Sossina Haile has been selected by the Solar Program of the Department of Energy Office of Energy Efficiency & Renewable Energy (EERE) to receive an EERE postdoctoral research award.

Tags: APhMS honors energy Sossina Haile Timothy Davenport postdocs

Developing Self-replicating Nanoscale Origami


William A. Goddard III, Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics, and colleagues including Postdoctoral Scholar Si-ping Han have been awarded a $2 million grant as part of the National Science Foundation’s Origami Design for Integration of Self-assembling Systems for Engineering Innovation program. The funds will be used to develop biomimetic materials which contain assembled complexes of molecules that self-replicate, evolve and adopt intricate three dimensional structures at the nanometer scale by combining DNA guided self-assembly with origami folding.

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Tags: APhMS research highlights health William Goddard Paul Rothemund Si-ping Han postdocs

Material's Spacing is Key to Brittle-to-ductile Transition


Julia R. Greer, her postdoctoral scholar Dr.Dongchan Jang, and colleagues have used experiments and atomistic simulations of nano-twinned metals (which have the unique combined effect of being strong and ductile) to decipher the specific role of the twin boundaries. They have found that it is the spacing between the twin boundaries that determines whether a material is brittle or ductile as opposed to the sample size, as would be expected. Greer states "this is probably the first study that truly isolated the twin boundaries by making samples which contained only twin boundaries, periodically spaced throughout the sample, and then tested them in tension. This understanding will help in the design of better structural materials and provide a certain amount of predictability in doing so, which has not been possible to date." [Nature Nanotechnology Article and Movies]

Tags: APhMS research highlights Julia Greer Dongchan Jang postdocs

Fueling Fundamental Research


To strengthen fundamental science and technology and foster transformational advances in renewable energies, the Dow Chemical Company and Caltech have established a $10 million partnership. Under the partnership, Dow will provide ongoing support for graduate student research through endowed fellowships which include five in energy science. The Resnick Sustainability Institute is receiving a significant portion of the funding in the agreement. Through the new Dow Chemical Company Bridge/CI2 Innovation Program, financial support will be used to further promising graduate and postdoc research that has the possibility of creating licensable technologies and start-ups. The graduate research fellowships in energy—renewable for up to two years—will help advance clean-energy goals. [Caltech Press Release]

Tags: APhMS energy Resnick Dow postdocs