Department of Applied Physics and Materials Science - Applied Physics

News & Events

Highlights

How Electrons Break the Speed Limit

12-10-19

Marco Bernardi, Assistant Professor of Applied Physics and Materials Science, and Jinjian Zhou, Postdoctoral Scholar, have developed a way to predict how electrons interacting strongly with atomic motions will flow through a complex material. "Using a new method, we have been able to predict both the formation and the dynamics of polarons in strontium titanate. This advance is crucial since many semiconductors and oxides of interest for future electronics and energy applications exhibit polaron effects," says Bernardi. [Caltech story]

Tags: APhMS research highlights Marco Bernardi Jinjian Zhou

Caltech Announces the Schmidt Academy for Software Engineering

10-10-19

Caltech has launched the Schmidt Academy for Software Engineering to train the next generation of science-savvy software engineers and set new standards in scientific software. "This is a recognition that computing, software, and machine learning are going to play a very big role in science. Because Caltech is small and collaborative, we have the opportunity to really make a push in that direction," says Kaushik Bhattacharya, the Howell N. Tyson, Sr., Professor of Mechanics and Materials Science and vice provost. [Caltech release]

Tags: APhMS EE research highlights MCE CMS Tapio Schneider Donnie Pinkston Kaushik Bhattacharya

New Metamaterial Changes Shape in a Tunable Fashion

09-12-19

Julia R. Greer, Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering, has developed a new type of architected metamaterial that has the ability to change shape in a tunable fashion. The material has potential applications in next-generation energy storage and bio-implantable micro-devices. [Caltech story]

Tags: APhMS research highlights MedE Julia Greer

Self-folding “Rollbot” paves the way for fully untethered soft robots

08-21-19

Chiara Daraio, Professor of Mechanical Engineering and Applied Physics, and colleagues have developed soft robotic systems, inspired by origami, that can move and change shape in response to external stimuli, paving the way for fully untethered soft robots. "This work demonstrates how the combination of responsive polymers in an architected composite can lead to materials with self-actuation in response to different stimuli. In the future, such materials can be programmed to perform ever more complex tasks, blurring the boundaries between materials and robots," said Professor Daraio. [Caltech story]

Tags: research highlights Chiara Daraio MCE APh

Finding the Magic in the Magic Angle

08-09-19

Stevan Nadj-Perge, Assistant Professor of Applied Physics and Materials Science, and colleagues have built upon, the discovery of the "magic angle" for stacked sheets of graphene, by generating an image of the atomic structure and electronic properties of magic angle-twisted graphene, yielding new insight into the phenomenon by offering a more direct way of studying it. They have developed a new method of creating samples of magic angle-twisted graphene that can be used to align the two sheets of graphene very precisely while leaving it exposed for direct observation. [Caltech story]

Tags: APhMS research highlights Stevan Nadj-Perge

Levitating Objects with Light

03-18-19

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]

Tags: APhMS research highlights Harry Atwater postdocs Ognjen Ilic

New Materials Exhibit Split Personality

02-01-19

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]

Tags: APhMS research highlights MCE Julia Greer

Microscopic Devices That Control Vibrations Could Allow Smaller Mobile Devices

12-12-18

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

"Folded" Optical Devices Manipulate Light in a New Way

10-30-18

Andrei Faraon, Professor of Applied Physics, and colleagues have introduced a technology called "folded metasurface optics," which is a way of printing multiple types of metasurfaces onto either side of a substrate, like glass. In this way, the substrate itself becomes the propagation space for the light. As a proof of concept, the team used the technique to build a spectrometer. Such compact spectrometers have a variety of possible uses, including as a noninvasive blood-glucose measuring system. [Caltech story]

Tags: research highlights Andrei Faraon APh

Caltech Startup Aims to Make Solar Panels More Efficient

10-18-18

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]

Tags: APhMS honors research highlights Harry Atwater alumni Thomas Russell Rebecca Saive