Department of Applied Physics and Materials Science - Applied Physics

News & Events

Highlights

Using Laser Light to Cool Object to Quantum Ground State

10-07-11

Oskar J. Painter, Professor of Applied Physics and Executive Officer for Applied Physics and Materials Science, and colleagues including graduate student Jasper Chan have cooled a miniature mechanical object—a tiny mechanical silicon beam— to its lowest possible energy state using laser light. The achievement paves the way for the development of exquisitely sensitive detectors. "In many ways, the experiment we've done provides a starting point for the really interesting quantum-mechanical experiments one wants to do," Painter says. [Caltech Press Release]

Tags: APhMS energy research highlights Oskar Painter Jasper Chan

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

Disorder Is Key to Nanotube Mystery

08-12-11

William A. Goddard III, Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics; and Posdoctoral Scholar Tod Pascal believe to have solved the mystery of why water spontaneously flows into extremely small tubes of graphite or graphene, called carbon nanotubes.  Using a novel method to calculate the dynamics of water molecules they have found that entropy is the missing key.  "It's a pretty surprising result," says Professor Goddard "People normally focus on energy in this problem, not entropy." [Caltech Press Release]

Tags: APhMS energy research highlights William Goddard Tod Pascal

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

One-way Transmission System for Sound Waves

07-26-11

Postdoctoral scholar, Georgios Theocharis, and GALCIT alumnus Nicholas Boechler; working with Professor Chiara Daraio, have created the first tunable acoustic diode- a device that allows acoustic information to travel only in one direction, at controllable frequencies. [Caltech Press Release]

Tags: APhMS energy research highlights Chiara Daraio GALCIT Georgios Theocharis Nicholas Boechler

Converting Heat into Electricity in Space and on Earth - High-Performance Bulk Thermoelectrics

05-23-11

Jeff Snyder, Faculty Associate in Applied Physics and Materials Science, and colleagues have developed a thermoelectric material that might be able to operate off nothing more than the heat of a car's exhaust. "You'll see applications wherever there's a solid-state advantage," Snyder predicts. "One example is the charging system. The electricity to keep your car's battery charged is generated by the alternator, a mechanical device driven by a rubber belt powered by the crankshaft. You've got friction, slippage, strain, internal resistance, wear and tear, and weight, in addition to the mechanical energy extracted to make the electricity. Just replacing that one subsystem with a thermoelectric solution could instantly improve a car's fuel efficiency by 10 percent." [Caltech Press Release]

Tags: APhMS energy research highlights Jeff Snyder

Experiments Settle Long-Standing Debate about Mysterious Array Formations in Nanofilms

05-19-11

Sandra M. Troian, Professor of Applied Physics, Aeronautics, and Mechanical Engineering, and colleagues' experiments have confirmed which of three possible mechanisms is responsible for the spontaneous formation of three-dimensional (3-D) pillar arrays in nanofilms (polymer films that are billionths of a meter thick). "My ultimate goal is to develop a suite of 3-D lithographic techniques based on remote, digital modulation of thermal, electrical, and magnetic surface forces," Troian says. Confirmation of the correct mechanism has allowed her to deduce the maximum resolution or minimum feature size ultimately possible with these patterning techniques. [Caltech Press Release]

Tags: APhMS research highlights GALCIT MCE Sandra Troian

Strong, Tough, and Now Cheap: New Way to Process Metallic Glass

05-12-11

William L. Johnson, Ruben F. and Donna Mettler Professor of Engineering and Applied Science, and his team of researchers have developed a new technique that allows them to make metallic-glass parts utilizing the same inexpensive processes used to produce plastic parts. "We've taken the economics of plastic manufacturing and applied it to a metal with superior engineering properties,” Professor Johnson says. "We end up with inexpensive, high-performance, precision net-shape parts made in the same way plastic parts are made—but made of a metal that's 20 times stronger and stiffer than plastic.” [Caltech Press Release]

Tags: APhMS research highlights William Johnson Metallic Glass

How an Idea Becomes a Business

03-29-11

Students in Ken Pickar's course Entrepreneurial Development (E 102) have the opportunity to identify a technology currently under study at Caltech and develop a business plan for it. The ideas used by the students this year included a solid-state memory technology developed by Jehoshua (Shuki) Bruck, Gordon and Betty Moore Professor of Computation and Neural Systems and Electrical Engineering. In this business plan the students proposed targeting Netflix and other high-volume streaming content providers. Another team pinpointed a new market for the vertical wind turbines of John O. Dabiri, Professor of Aeronautics and Bioengineering. A third team pitched a noninvasive method for breaking up arterial plaques using the concentrated-acoustic-pulse technology developed by Chiara Daraio, Professor of Aeronautics and Applied Physics. [Caltech Feature]

Tags: APhMS EE research highlights Chiara Daraio GALCIT Jehoshua Bruck John Dabiri Ken Pickar

New Reactor Paves the Way for Efficiently Producing Fuel from Sunlight

01-20-11

Sossina Haile, Professor of Materials Science and Chemical Engineering, and colleagues have built a reactor at the heart of which is a cylindrical lining of ceria—a metal oxide. The reactor takes advantage of ceria's ability to "exhale" oxygen from its crystalline framework at very high temperatures and then "inhale" oxygen back in at lower temperatures - concentrating solar energy in order to convert carbon dioxide and water into fuels .  Ultimately, Haile says, the process could be adopted in large-scale energy plants, allowing solar-derived power to be reliably available during the day and night. [Caltech Press Release]

Tags: APhMS energy research highlights Sossina Haile fuel metal oxide reactor