Department of Applied Physics and Materials Science - Applied Physics

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Highlights

Material Inspired by Chain Mail Transforms from Flexible to Rigid on Command

08-12-21

Engineers at Caltech and JPL have developed a material inspired by chain mail that can transform from a foldable, fluid-like state into specific solid shapes under pressure. "We wanted to make materials that can change stiffness on command," says Chiara Daraio, G. Bradford Jones Professor of Mechanical Engineering and Applied Physics. "We'd like to create a fabric that goes from soft and foldable to rigid and load-bearing in a controllable way." To explore what materials would work best, Daraio, together with former Caltech postdoctoral researcher Yifan Wang and former Caltech graduate student Liuchi Li (PhD '19) as co-lead authors of the Nature paper, designed a number of configurations of linked particles, from linking rings to linking cubes to linking octahedrons (which resemble two pyramids connected at the base). The materials were 3-D printed out of polymers and even metals, with help from Douglas Hofmann, principal scientist at JPL, which Caltech manages for NASA. These configurations were then simulated in a computer with a model from the group of José E. Andrade, the George W. Housner Professor of Civil and Mechanical Engineering and Caltech's resident expert in the modeling of granular materials. [Caltech story]

Tags: APhMS Chiara Daraio MCE Jose Andrade KNI Yifan Wang Liuchi Li

Joseph Falson Named Moore Fellow

08-11-21

Joseph Falson, Assistant Professor of Materials Science, has been named as a 2021 Fellow in Materials Synthesis by the Gordon and Betty Moore Foundation. Falson's grant will enable him to pursue methods for growing highly pure crystals of new materials. He plans to build a custom piece of equipment with an ultra-high vacuum chamber corrosive materials that also offers access to the materials so that sensitive experiments may be conducted on them. "Broadly, the field is looking for fundamentally new types of materials that show some type of complex functionality," says Falson. [Caltech story]

Tags: APhMS honors KNI Joseph Falson

Wei Gao Receives Pittsburgh Conference Achievement Award

07-07-21

Wei Gao, Assistant Professor of Medical Engineering, has received the Pittsburgh Conference Achievement Award (PCAA). The Pittsburgh Conference Achievement Award is given annually to a researcher who has made a significant and independent impact in the area of analytical chemistry within the first ten years after his or her doctoral degree. [Past Recipients]

Tags: APhMS honors MedE KNI Wei Gao

Nano-Architected Material Resists Impact Better Than Kevlar

06-25-21

Julia R. Greer, Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering; Fletcher Jones Foundation Director of the Kavli Nanoscience Institute, has developed a nano-architected material made from tiny carbon struts that is, pound for pound, more effective at stopping a projectile than Kevlar, a material commonly used in personal protective gear. "The knowledge from this work could provide design principles for ultra-lightweight impact resistant materials for use in efficient armor materials, protective coatings, and blast-resistant shields desirable in defense and space applications," says Greer. [Caltech story]

Tags: APhMS research highlights MedE MCE Julia Greer KNI

Graduate Students Receive KNI Catalyst Awards

05-04-21

Haley Bauser and Daniel Mukasa are recipients of the inaugural 2021 KNI Catalyst Award. The Kavli Nanoscience Institute established the KNI Catalyst Awards to recognize researchers in the nanoscience community who actively promote diversity, equity and/or inclusion at Caltech, JPL, or the broader scientific community. [KNI Release]

Tags: APhMS honors KNI Daniel Mukasa Haley Bauser

Wei Gao Receives 3M Non-Tenured Faculty Award

03-08-21

Wei Gao, Assistant Professor of Medical Engineering, has been selected to receive the prestigious 3M Non-Tenured Faculty Award from 3M Corporation. This award recognizes outstanding new faculty who were nominated by 3M researchers and selected based on their research, experience and academic leadership. The purpose of the award is to help the faculty members achieve tenure, remain in their teaching position, and conduct research.

Tags: APhMS honors MedE KNI Wei Gao

New Insight into Nonlinear Optical Resonators Unlocks Door to Numerous Potential Applications

02-25-21

Devices known as optical parametric oscillators are among the widely used nonlinear resonators in optics; they are "nonlinear" in that there is light flowing into the system and light leaking out, but not at the same wavelengths. Though these oscillators are useful in a variety of applications, including in quantum optics experiments, the physics that underpins how their output wavelength, or spectrum, behaves is not well understood. "When you add strong nonlinearity to resonators, you enter what we call a 'rich physics regime,'" says Alireza Marandi, Assistant Professor of Electrical Engineering and Applied Physics. "'Rich' in physics terms usually means complicated and hard to use, but we need nonlinearities to create useful functionalities such as switching for computing." To be able to make full use of nonlinear optical resonators, researchers want to be able to understand and model the physics that underpin how they work. Marandi and his colleagues recently uncovered a potential way to engineer those rich physics, while discovering phase transitions in the light that is generated by the resonators. [Caltech story]

Tags: APhMS EE research highlights KNI Alireza Marandi

Caltech and NTT Research Launch Collaboration to Develop World’s Fastest Coherent Ising Machine

01-25-21

Researchers from Caltech and NTT Research are collaborating to develop a high-speed Coherent Ising Machine (CIM). A CIM is a network of optical parametric oscillators (OPOs) programmed to solve problems that have been mapped to an Ising model, which is a mathematical abstraction of magnetic systems composed of competitively interacting spins, or angular momentums of fundamental particles. The principal investigator at Caltech for this four-and-a-half-year joint project is Kerry Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics; Executive Officer for Applied Physics and Materials Science. “We are delighted at the prospect of working with Professor Vahala to develop an extremely small and high-speed CIM,” said NTT Research PHI Lab Director, Yoshihisa Yamamoto. “This work will advance our understanding of the CIM’s capabilities, map well with ongoing and related work with other institutions, provide new demonstrations of this awesomely powerful new information system and, we hope, set standards for the CIM’s speed and size.” [NTT Research story] [Business Wire story]

Tags: APhMS research highlights Kerry Vahala KNI

Tiny Shape-Shifting Polymers Developed for Potential Medical Applications

01-04-21

Julia Greer, Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering; Fletcher Jones Foundation Director of the Kavli Nanoscience Institute, has developed a process for generating three-dimensional architected polymers with heat-dependent "shape memory" properties: that is, when heated, the material folds and unfolds itself into a new preordained shape. These shape memory polymers could one day be used to perform complex tasks inside the human body, such as unclogging a blocked artery or pulling out a blood clot. [Caltech story]

Tags: APhMS research highlights MedE Julia Greer KNI Luizetta Elliott

Titanium Atom That Exists in Two Places at Once in Crystal to Blame for Unusual Phenomenon

12-07-20

Crystals are usually good at conducting heat. By definition, their atomic structure is highly organized, which allows atomic vibrations—heat—to flow through them as a wave. Austin Minnich, Professor of Mechanical Engineering and Applied Physics, has discovered why a perfect crystal is not good at conducting heat, although it seemingly should be. "We have found that quantum mechanical effects can play a huge role in setting the thermal transport properties of materials even under familiar conditions like room temperature," says Austin Minnich. [Caltech story]

Tags: APhMS research highlights MCE KNI Austin Minnich