Christopher M. Spadaccini, Ph.D.
Director, Additive Manufacturing Initiative
Director, Center for Engineered Materials and Manufacturing
Lawrence Livermore National Laboratory
12 PM, Monday, April 10th, 2017
1065 Kemper Hall
Abstract: Material properties are governed by the chemical composition and spatial arrangement of constituent elements at multiple length-scales. This fundamentally limits material properties with respect to each other creating trade-offs when selecting materials for specific applications. For example, strength and density are inherently linked so that, in general, the denser the material, the stronger it is in bulk form. We are combining advanced microstructural design, using flexure and screw theory as well as topology optimization, with advanced additive micro- and nanomanufacturing techniques to create new material systems with previously unachievable property combinations – mechanical metamaterials. The performance of these materials is fundamentally controlled by geometry at multiple length-scales rather than chemical composition alone. We have demonstrated designer properties of these mechanical metamaterials in polymers, metals, ceramics and combinations thereof. Properties include ultra-stiff lightweight materials, negative stiffness, and negative thermal expansion. Our additive micro-manufacturing techniques include Projection Microstereolithography (PµSL), Direct Ink Writing (DIW), and Electrophoretic Deposition (EPD) as well as some new advanced concepts such as volumetric 3D printing and high throughput layer-at-once metal printing using diode lasers. These tools are capable of generating the designed structures which are highly three-dimensional micro- and nano-scale architectures with multiple constituent materials in the same structure.
Biography: Christopher M. Spadaccini, Ph.D., is currently the Director of the Additive Manufacturing Initiative at the Lawrence Livermore National Laboratory (LLNL) as well as the leader of the Center for Engineered Materials and Manufacturing. He has been working in advanced additive manufacturing process development and architected materials for the last decade and has over 30 publications and several dozen patents awarded and pending. Dr. Spadaccini founded several new fabrication laboratories at LLNL for process development focused on micro and nano-scale features and mixed material printing. He received his B.S., M.S. and Ph.D. degrees from the Department of Aeronautics and Astronautics at the Massachusetts Institute of Technology (MIT) in 1997, 1999, and 2004 respectively and has been a member of the LLNL technical staff for 13 years.