MSE Colloquium: Matthew Begley, Acoustic Assembly and Field-Assisted 3D Printing of Multi-component Materials
The ability to control microstructure ‘on-the-fly’ during 3D printing creates significant opportunities for new functionality, as it allows the spatial integration of local properties and component geometry. For example, this capability would allow one to print complex, 3D antennas using a single ink of conductive particles suspended in an insulating matrix, with conducting regions created by packing the particles above the percolation limit. Similarly, it would be possible to print battery electrodes with spatial gradients in porosity that facilitate ion transport and storage. This talk will describe the development novel 3D printing nozzles for direct deposition of two-phase materials, which exploit acoustic focusing to assemble colloidal solids and control composite microstructures during deposition. Since acoustic assembly is relatively material agnostic (i.e. not dependent on specific compositions or surface chemistry), it can be combined with chemical self-assembly to create hierarchical assembly platforms to fabricate macroscale specimens from nanoparticles. The talk will describe theory and experiments intended to establish the potential of acoustic-based assembly, including (i) printing regime maps that identify system parameters that lead to effective “on-the-fly” assembly during direct deposition, (ii) printed filaments of short SiC fiber-epoxy filaments with fiber alignment from acoustics, and (iii) rapid assembly of millimeter-scale specimens of colloidal solid, consisting of surface functionalized gold nanoparticles and polymer micro-beads. The talk will conclude with a brief discussion of the implications of these results with respect to achieving specific microstructures.
Matthew R. Begley is a Professor of Mechanical Engineering and Professor of Materials at the University of California, Santa Barbara. His research focuses on simulating the behavior of composites and multilayer devices, with an emphasis on micromechanics and computational mechanics. Professor Begley earned his Ph.D. from UCSB in 1995, and was a post-doctoral fellow at Harvard from 1995-1997. Following a faculty appointment at UConn from 1997-2001, Prof. Begley held joint appointments in MSE, ME and ECE at the University of Virginia from 2001-2009. Prof. Begley served as an Associate Editor of the ASME Journal of Applied Mechanics from 2005-2011. Professor Begley’s honors include: NSF Career Award (2000), Invited Key Speaker at the Advanced Metallization Conference (2003), Invited Speaker at the Gordon Conference on Thin Films (2006), Winner in the DARPA DMACE Challenge (co-leader, 2010), Invited Speaker at the Gordon Conference on the Physics and Chemistry of Microfluidics (2013), the Fraunhofer-Bessel Fellowship from the Humboldt Foundation (Germany, 2014), Keynote Lecture at the uTAS Conference (2016).