Department of Applied Physics and Materials Science - Materials Science

News & Events

Highlights

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

07-16-12

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

Winners of the 2012 Demetriades - Tsafka - Kokkalis Prizes Announced

06-14-12

The student winners of the 2012 Demetriades - Tsafka - Kokkalis Prizes were announced at a special luncheon with the Demetriades - Tsafka – Kokkalis family. Philip Romero received the prize in Biotechnology for his work on developing statistical models of proteins with Frances Arnold. Michael Mello was the recipient of the prize in Seismo-Engineering, Prediction, and Protection for his work with Ares Rosakis on developing a novel methodology for identifying the unique ground motion signatures of supershear earthquakes. Leslie O’Leary received the prize in Environmentally Benign Renewable Energy Sources for her pathbreaking work on the properties of semiconductor interfaces with Nate Lewis and Bob Grubbs. This year there were two winners for the prize in Nanotechnology. One winner was Andrew Jennings for his experimental and modeling work in nanomechanics with Julia Greer. The other winner of the Nanotechnology prize was Jordan Raney who has worked with Chiara Daraio to develop new chemical synthesis methods to control the properties of carbon nanotubes.

Tags: APhMS honors research highlights Chiara Daraio GALCIT MCE Nate Lewis Julia Greer Ares Rosakis Demetriades - Tsafka - Kokkalis Philip Romero Frances Arnold. Michael Mello Leslie O’Leary Bob Grubbs Andrew Jennings Jordan Raney

APhMS and EE Students Engineer a One-of-a-kind Machine

06-13-12

Applied Physics graduate student, Peter Hung, along with Electrical Engineering undergraduate students Julie Jester, Jeff Sherman, and Sean Keenan, worked with a team of engineering students from across the country to create a one-of-a-kind machine for sharing a Coke.

Tags: APhMS EE Peter Hung Julie Jester Jeff Sherman Sean Keenan

Better, Stronger, Lighter Armor

05-22-12

Kaushik Bhattacharya, Howell N. Tyson, Sr., Professor of Mechanics and Professor of Materials Science, is the Caltech lead on a $90 million U.S. Army Research Laboratory funded program to improve protective gear and vehicles for soldiers. "…studying materials in very extreme conditions is an area where Caltech engineering really stand out," says Bhattacharya. "The tools we bring, on both the theoretical and experimental sides uniquely bridge deep fundamental principles with unprecedented application.” [Caltech Feature]

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Tags: APhMS GALCIT MCE Guruswami Ravichandran Julia Greer William Goddard Michael Ortiz Dennis Kochmann Kaushik Bhattacharya

Light as a Feather, Stiffer Than a Board

11-18-11

Julia R. Greer, Assistant Professor of Materials Science and Mechanics, and colleagues have developed the world’s lightest solid material, with a density of 0.9 milligrams per cubic centimeter. The new material, called a micro-lattice, relies, on a lattice architecture: tiny hollow tubes made of nickel-phosphorous are angled to connect at nodes, forming repeating, asterisklike unit cells in three dimensions. "We're entering a new era of materials science where material properties are determined not only by the microscopic makeup of the material but also by the architecture of the constituents," Greer says. [Caltech Feature]

Tags: APhMS research highlights Julia Greer

Professor Greer Receives Sia Nemat-Nasser Early Career Award

10-07-11

Julia R. Greer, Assistant Professor of Materials Science and Mechanics, has been selected by the American Society of Mechanical Engineers (ASME) Materials Division Executive Committee to receive the 2011 Sia Nemat-Nasser Early Career Award for her research contributions in “physical origins of size-dependent mechanical properties in nano-scale solids”.

Tags: APhMS honors Julia Greer

Nano-mechanics of Carbon Nanotube Research Wins Art Competition

08-22-11

Siddhartha (Sid) Pathak, a W. M. Keck Institute for Space Studies (KISS) Postdoctoral Fellow in Material Science, has received the first prize in the NanoArt 2011 International Competition. The inspiration for Dr. Pathak's entry entitled "In-situ SEM deformation of CNT micro-pillars" is his research on nano-mechanics of carbon nanotubes.  As a KISS postdoc Dr. Pathak is working with  Professor Julia Greer on mechanical testing of carbon nanotubes at submicron length scales, with a particular emphasis towards space applications.  

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Tags: APhMS energy research highlights Julia Greer KISS Siddhartha Pathak postdocs

Engineers Solve Longstanding Problem in Photonic Chip Technology

08-04-11

Liang Feng, a Postdoctoral Scholar in Electrical Engineering who works with Professor Axel Scherer, has designed a new type of optical waveguide - a 0.8-micron-wide silicon device. The waveguide allows light to go in one direction but changes the mode of the light when it travels in the opposite direction. This new technique to isolate light signals on a silicon chip, solves a longstanding problem in engineering photonic chips. [Caltech Press Release]

Tags: APhMS EE energy research highlights Liang Feng Axel Scherer postdocs

Professor Greer Receives DOE Early Career Research Award

05-06-11

Julia R. Greer, Assistant Professor of Materials Science and Mechanics, has received a five-year award from the Department of Energy Office of Science's Early Career Research Program for her proposal entitled “Investigation of radiation damage tolerance in interface‐containing metallic nano structures”. These research awards provide incentives for exceptional researchers, during the crucial early career years, to focus on research areas that are a high priority for the Department of Energy and the Nation. [Caltech Feature]

Tags: APhMS honors MCE Julia Greer DOE Career DOE

Professor Greer Receives 2011 TMS Young Leader Professional Development Award

04-08-11

Julia R. Greer, Assistant Professor of Materials Science and Mechanics, is one of ten, and the only female, to receive the 2011 TMS Young Leader Professional Development Award. This award gives young members of the Minerals, Metals, & Materials Society (TMS) the opportunity to advance in the field of Materials Science through interaction with TMS division leaders, and participation in the decision-making and long range planning of the society. Congratulations Professor Greer! [The Young Leader Newsletter]

Tags: APhMS honors MCE Julia Greer