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]
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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]
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Joseph Falson
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]
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MedE
MCE
Julia Greer
KNI
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.
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MedE
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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]
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Alireza Marandi
Paul Rothemund Places Molecule-Scale Devices in Precise Orientation
02-22-21
Paul Rothemund, Research Professor of Bioengineering, Computing and Mathematical Sciences, and Computation and Neural Systems, has developed a technique that allows him to precisely place microscopic devices formed from folded DNA molecules in not only a specific location but also in a specific orientation. This method for precisely placing and orienting DNA-based molecular devices may make it possible to use these molecular devices to power new kinds of chips that integrate molecular biosensors with optics and electronics for applications such as DNA sequencing or measuring the concentrations of thousands of proteins at once. [Caltech story]
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CMS
Paul Rothemund
KNI
CNS