Microstructures Self-Assemble into New Materials
03-03-20
A new process developed at Caltech makes it possible for the first time to manufacture large quantities of materials whose structure is designed at a nanometer scale—the size of DNA's double helix. Pioneered by 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, "nanoarchitected materials" exhibit unusual, often surprising properties—for example, exceptionally lightweight ceramics that spring back to their original shape, like a sponge, after being compressed. Now, a team of engineers at Caltech and ETH Zurich have developed a material that is designed at the nanoscale but assembles itself—with no need for the precision laser assembly. "We couldn't 3-D print this much nanoarchitected material even in a month; instead we're able to grow it in a matter of hours," says Carlos M. Portela, Postdoctoral Scholar. "It is exciting to see our computationally designed optimal nanoscale architectures being realized experimentally in the lab," says Dennis M. Kochmann, Visiting Associate. [Caltech story]
Tags:
APhMS
research highlights
GALCIT
MedE
MCE
Julia Greer
KNI
Dennis Kochmann
postdocs
Carlos Portela
Sweat Sensor Detects Stress Levels; May Find Use in Space Exploration
02-27-20
Wei Gao, Assistant Professor of Medical Engineering, has produced a wireless sweat sensor that can accurately detect levels of cortisol, a natural compound that is commonly thought of as the body's stress hormone. This could allow for more widespread and easier monitoring of stress, anxiety, post-traumatic stress disorder, and depression. "We aim to develop a wearable system that can collect multimodal data, including both vital sign and molecular biomarker information, to obtain the accurate classification for deep space stress and anxiety," Gao says. [Caltech story]
Tags:
APhMS
research highlights
MedE
KNI
Wei Gao
Ultrasound Can Selectively Kill Cancer Cells
02-05-20
Michael Ortiz, Frank and Ora Lee Marble Professor of Aeronautics and Mechanical Engineering, Emeritus, and Morteza Gharib, Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering; Booth-Kresa Leadership Chair, Center for Autonomous Systems and Technologies; Director, Graduate Aerospace Laboratories; Director, Center for Autonomous Systems and Technologies, are exploring a new technique that could offer a targeted approach to fighting cancer. Low-intensity pulses of ultrasound have been shown to selectively kill cancer cells while leaving normal cells unharmed. In the past, ultrasound waves have been used as a cancer treatment with high-intensity bursts resulting in killing cancer and normal cells. [Caltech story]
Tags:
APhMS
research highlights
GALCIT
MedE
MCE
Morteza Gharib
Michael Ortiz
Researchers Develop New Quantum Algorithm
12-19-19
Austin Minnich, Professor of Mechanical Engineering and Applied Physics, Fernando Brandão, Bren Professor of Theoretical Physics, and Garnet Chan, Bren Professor of Chemistry, have developed an algorithm for quantum computers that will help them find use in simulations in the physical sciences. The new algorithm allows a user to find the lowest energy of a given molecule or material. Many people are interested in how to simulate the ground states of molecules and materials. "If we want to do a simulation of water, we could look at how water behaves after it has been blasted into a plasma—an electrically charged gas—but that's not the state water is usually found in; it is not the ground state of water. Ground states are of special interest in understanding the world under ordinary conditions," says Chan. [Caltech story]
Tags:
APhMS
research highlights
MCE
KNI
Austin Minnich
Fernando Brandão
Garnet Chan
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
postdocs
Jinjian Zhou
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
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