Materials professor Tresa Pollock, chair of the Materials Science Department at the UC Santa Barbara College of Engineering, has received one of thirteen prestigious 2017 Vannevar Bush Faculty Fellowships from the U.S. Department of Defense. The fellowship includes $3 million to fund five years of Pollock’s research, which is aimed at developing a 3D Platform for discovering new materials that could operate in extreme environments such as those experienced by rockets, aircraft engines, and hypersonic flight vehicles.
“I am very honored to be selected for this award, which is named after a visionary scientist who shaped the U.S. research infrastructure,” Pollock said. “I am also grateful for the research support this provides, and for the support the DoD has provided for many of my previous research efforts. The Vannevar Bush Fellowship will allow us to pursue research in directions not possible with other types of research programs.”
"For Tresa Pollock to receive a prestigious Vannever Bush Award from the U.S. Department of Defense is a tremendous and well-deserved honor,” said Rod Alferness, dean of the College of Engineering. “I have no doubt that the funding that comes with the fellowship will enable her and her team to develop breakthroughs in 3D printing, nanoscale analysis, and efficient production of important new materials.”
The fellowship program provides research awards to top-tier researchers from U.S. universities to conduct revolutionary “high risk, high pay-off” research that addresses the “hard” problems that DoD needs to solve, according to the Vannever Bush Awards website. “Printing advanced materials into complex architectures on demand poses many technical challenges. This fellowship will enable us to tackle what are currently limiting materials-science issues,” Pollock said. “The award builds on our previous research on crystal growth and solidification, 3D materials science, and alloy design. These intellectually challenging areas of research are highly suited to the talented PhD students who study at UCSB.”
In recent years, it has become possible to use laser beams and electron beams to “print” engineering objects that have complex shapes. The process involves melting and fusing metallic powder particles — each about ten times finer than a grain of local beach sand — in millimeter- scale “pools” created by local focusing of a laser or electron beam.
Drawing from the entire periodic table, it would be possible to mix and print millions of metallic powders having different combinations of elements. But until now, Pollock explained, it has been possible to print with only six or seven types of powders, because not enough was known about the complex series of events that occur during the melting, mixing, and vaporization of the material that occur when the powder bed is scanned by a high-intensity beam, and afterward, as the material cools.
“The grand challenges for making materials in this fashion are two-fold and three-dimensional: we need to design material compositions in which defects will not form during melting and cooling within the cubic-millimeter pool, and we need 3D tools to examine the structure of that millimeter-scale volume of material at the nanometer scale, to ensure that the structure is sound,” Pollock says. “The Vannevar Bush fellowship will enable us to focus on these two aspects of the printing problem.”
Building upon a combined laser and electron-beam tomography system she developed at UCSB, Pollock will design and integrate an additional open-source, highly automated laser-powder-processing platform that can be operated either in layer-by-layer additive build mode for a given material or in combinatorial chemistry mode to vary chemistry locally.
Pollock says that the 3D platform will enable exploration of previously inaccessible design spaces of higher-dimensional compositional materials, and will also provide rapid acquisition of 3D information about the materials’ chemistry, structure, and crystallography, from the nanometer-to-millimeter length scales critical in emerging approaches to additive manufacturing.