Updated May 17th, 2017
Two Livermore researchers were among the recipients named by President Obama for the prestigious Presidential Early Career Awards for Scientists and Engineers (PECASE), announced in Washington D.C. January 9. Jonathan Belof and Eric Duoss joined 100 others in winning the highest honor the U.S. government gives to scientists and engineers for innovative research and community service in the early stages of their independent careers. Belof has performed research in stockpile stewardship at the Laboratory since 2010. He won for his work in phase transition dynamics and non-equilibrium systems, as well as his efforts in teaching science, technology, engineering, and math (STEM). “It’s just overwhelming, in a good way. It’s a tremendous honor and I’m just really humbled by this award,” Belof says.
Duoss conducts research in advanced materials and manufacturing combined with micro-architected design and has worked at Livermore since 2010. In addition to his programmatic work, Duoss has dedicated himself to educating the younger generation of scientists and engineers about STEM pathways, volunteering countless hours and conducting Laboratory tours for students and teachers. “This is truly a recognition of the kind of environment we have that early career scientists and engineers can do creative and exciting things,” he says.
The High-Repetition-Rate Advanced Petawatt Laser System (HAPLS) recently completed a significant milestone: Livermore demonstrated continuous operation of an all diode-pumped, high-energy femtosecond petawatt laser system. (One petawatt is one million billion watts. A femtosecond is a millionth billionth of a second.) With its completion, the system is ready for delivery and integration at the European Extreme Light Infrastructure Beamlines facility project in the Czech Republic.
HAPLS set a world record for diode-pumped petawatt lasers: the energy of a 28-femtosecond-long laser pulse reached 16 joules at 3.3 pulses per second. In just three years, HAPLS went from concept to a fully integrated and record-breaking product. HAPLS represents a new generation of high-energy, high-peak-power laser systems that use innovative technologies originating from the Department of Energy’s fusion laser research and development. “Lawrence Livermore takes pride in pushing science and technology to regimes never achieved before,” says Livermore Director Bill Goldstein. “Twenty years ago, Livermore pioneered the first petawatt laser—the NOVA Petawatt—representing a quantum leap forward in peak power. Today, HAPLS leads a new generation of petawatt lasers, with capabilities not seen before.”
Livermore researchers have become the first to 3D-print aerospace-grade carbon fiber composites, opening the door to greater control and optimization of the lightweight, yet stronger-than-steel material. The research, published by the journal Nature Scientific Reports online on March 6, represents a “significant advance” in the development of micro-extrusion 3D printing techniques for carbon fiber, the authors reported. Carbon fiber is a lightweight, yet stiff and strong material with a high resistance to temperature, making the material popular in the aerospace, defense, and automotive industries, and sports.
Carbon fiber composites are typically fabricated one of two ways—by physically winding the filaments around a mandrel, or weaving the fibers together like a wicker basket, resulting in finished products that are limited to either flat or cylindrical shapes. To maximize performance, fabricators tend to overcompensate with extra material, making the parts heavier, costlier, and more wasteful than necessary. Livermore researchers reported printing several complex 3D structures through a modified direct-ink-writing 3D printing process that reduces waste. The team also developed and patented a new chemistry that can cure the material in seconds instead of hours, and used the Laboratory’s high-performance computing capabilities to develop accurate models of the flow of carbon fiber filaments. The Laboratory Directed Research and Development program funded the study (15-ERD-030).
Livermore scientists and collaborators from the University of Wisconsin and elsewhere have developed an integrated, simple, and sensitive diagnostic test kit that detects pathogens from the ESKAPE bacterial collection. These bacteria are responsible for the majority of hospital-acquired infections and are resistant to many antibiotics. The work has been accepted for publication in Applied and Environmental Microbiology and has been selected by the journal editors for inclusion in “Spotlight,” a feature that highlights significant research articles.
The diagnostic kit can run tests rapidly from liquid samples on an autonomous plastic cartridge. Results are imaged in a portable reader and sent to a smartphone or tablet to help the health-care provider make treatment decisions. The diagnostic kit meets a need for a kit to detect pathogenic bacteria easily and sensitively in resource-limited places and provide effective antibiotic therapies for infected patients. The kit will also have a role in other areas beyond human health where rapid detection is valuable, including food security, agriculture, water quality, and industrial processing and manufacturing.
Livermore researchers, with collaborators at Worchester Polytechnic Institute, are taking a new approach to metal 3D printing with a process they call direct metal writing, in which semisolid metal is directly extruded from a nozzle. The metal is engineered to be a shear thinning material, which means it acts like a solid when standing still, but flows like a liquid when a force is applied. The results of the ongoing three-year study were published in Applied Physics Letters. Metal 3D printing has enormous potential to revolutionize modern manufacturing, but the most popular metal printing processes, which use lasers to fuse together fine metal powder, have limitations. Selective laser melting and other powder-based metal techniques often result in gaps or defects.
Instead of starting with metal powder, the direct metal writing technique uses an ingot that is heated until it reaches a semi-solid state—solid metal particles are surrounded by a liquid metal, resulting in a paste-like behavior. “We’re in new territory. We’ve advanced a new metal additive manufacturing technique that people aren’t aware of yet. I think a lot of people will be interested in continuing this work and expanding it into other alloys,” says lead author Wen Chen, a Livermore materials scientist. The project is funded by the Laboratory Directed Research & Development program (14-SI-004).