Silver is a really interesting metal. Of all the metals, it has the highest electrical and thermal conductivity. It's also very corrosion and oxidation resistant. Why isn't it used in more electronics and thermal management applications? The answer: traditionally, silver is avoided because of the high cost. However, modern technology has become so complex that the raw materials cost is often a tiny fraction of total value. It's time to re-evaluate silver for many electronics technologies. I'm especially interested in nanosilver-based electronics materials. While the melting point of solid silver is 962 C, silver nanoparticles can melt at temperatures as low as 100 C (or even lower) and exhibit enhanced surface diffusion. This is fascinating from a scientific perspective. Practically, it means that silver nanopastes can be easily shaped and then consolidated to solid silver at temperatures achievable with a typical soldering iron. Thus, nanosilver could find use as a solder alternative, a high-performance semiconductor chip glue, and many other applications. I study the consolidation phenomena in these materials, their thermomechanical creep behavior at temperatures relevant to power electronics applications, and am working to develop novel nanosilver/polymer composites. In the future, I'd like to study the effect of alloying elements on nanosilver consolidation behavior, as a way of controlling the zero-stress point in electronics packages. 

Natural wood is an ancient material. While we think of wood as low-tech, it actually has surprisingly good stiffness-to-weight and strength-to-weight ratios, even when compared to advanced composites. In recent years, there's been a breakthrough (Hu et. al., https://doi.org/10.1038/nature25476) in the form of a thermo-chemo-mechanical treatment that can enhance the properties of natural wood by a factor of 6 or 7. This treatment involves the careful removal of a controlled amount of lignin, followed by a heat-and-pressure treatment to align and enhance bonding between the cellulose fibers that give the wood its strength. There are many aspects of this process that remain to be studied. We use microscopy, x-ray diffraction and x-ray photoelectron spectroscopy to study the processing-property relationships in these enhanced wood materials, and to understand the cellulose crystallization phenomena that occur during enhancement.  

Metal additive manufacturing (AM) is a new and rapidly growing field. It's become clear that metal AM methods are going to change the way that many metal components are manufactured, both at the new cutting edge, where otherwise impossible geometries and materials become accessible, and in the area of legacy tehcnology, where unavailable replacement parts can be easily manufactured without the need for expensive tooling. However, there are still many questions regarding microstructure and mechanical properties that arise as a result of local thermal history during AM. I study the effect of part size on the mechanical, fatigue and microstructure of Nickel-based superalloys.

Everyone understands the importance of being able to remove contaminents from water. While lead has recieved the most attention in the media, another class of chemicals has become a concern. Recently, we've come to understand that per- and polyfluoroalkyl (PFAS) chemicals, while extremely useful, persist in our drinking water supply for a very long time, and can be harmful to humans. The search is on for materials that could be used to selectively absorb these chemicals.  This project focuses on the use of several classes of metal-organic framework (MOF) materials as potential PFAS absorbers. X-ray photoelectron spectroscopy is a large part of this project, allowing us to study the chemistry and kinetics of PFAS/MOF interactions. 

My teaching is primarily focused on training undergraduate engineers in both Materials and Mechanical fields. I regularly teach classes in Metallography, Mechanical Testing, Mechanical Properties of Materials, Introduction to Materials Engineering, Mechanical Metallurgy, Thermodynamics of Materials, Kinetics and Diffusion of Materials, and Powder Processing of Materials. I have also taught Solid Modeling and Solidworks, and have served as the organizer for the College of Engineering and Computer Science Ph.D. Seminar series. When I teach, I strive to present the proper ratio of theory and engineering practice. This ratio varies widely depending on the specific engineering topic. For example, Thermodynamics of Materials is probably 80% theory, while Powder Processing of Materials is the opposite. My lecture style involves a large amount of in-person board work, using both traditional whiteboard and tablet-projection approaches. Computer presentation software is used for graphical information, but is otherwise kept to a minimum. I query my classes frequently so that I can dynamically adjust my lecture content. I also use software-based engineering examples whenever appropriate. In practice, this means that my lectures often switch back and forth between computer and whiteboard. While this may be a staid approach, I've found that students vastly prefer this to other up-and-coming teaching strategies, and it seems to keep them effectively engaged. I welcome the time when online learning, MOOCs, flipped classrooms, gamified classes, etc. become more effective than the traditional university classroom. However, when it comes to teaching in-depth engineering, my impression is that these other methods aren't quite there yet. 

1. J. R. McCoppin, M. S. Hanchak, L. J. Elston, D. Young, “Boil-Off Calorimetry Enthalpy Measurements and Equation of State of an Aqueous Pyridine Azeotrope,” Intl. Journal of Refrigeration (2021)
2. J.R. McCoppin and D. Young, “Mass Transport, Creep and Zero-Stress-Point Shifting in a Nano-Silver Die Attach Material During Thermal Cycling,” Journal of Electronic Materials, 49 (2020) 3982-3989.
3. J. McCoppin, T. Reitz, R. Miller, H. Jijwani, S. Mukhopadhyay, D. Young, “Low Temperature Consolidation of Micro/Nanosilver Die-Attach Preforms,” Journal of Electronic Materials, vol. 43 (2014) 3379-3388.
4. J. McCoppin, I. Barney, S. Mukhopadhyay, R. Miller, T. Reitz, D. Young, “Compositional control of continuously graded anode functional layer,” Journal of Power Sources, 215 (2012) 160-163.
5. J. McCoppin, D. Young, T. Reitz, A. Maleszewski, S. Mukhopadhyay, “Solid oxide fuel cell with compositionally graded cathode functional layer deposited by pressure assisted dual-suspension spraying,” Journal of Power Sources, 196 (2011) 3761–3765.
6. D. Young, M. A. Sukeshini, R. Cummins, H. Xiao, M. Rottmayer, T. Reitz, “Inkjet Printing of Electrolyte and Anode Functional layer for Solid Oxide Fuel Cells,” Journal of Power Sources, vol. 184 (2008) 191-196.
7. M. Gorantla, S. E. Boone, C. Clark, R. Esser, M. El-Ashry, D. Young, "Extrusion of a Solvated Polymer Into a Moving Viscous Medium Allows Generation of Continuous Polymer Nanofibers Via Hydrodynamic Focusing," Journal of Materials Research, vol. 12 no. 4, (2007) 989-993.
8. B. R. Ringeisen, C. M. Othon, J. A. Barron, D. Young and B. J. Spargo, "Jet-based methods to print living cells," Biotechnology Journal, vol. 1, no. 9 (2006) 930-948.
9. M. Gorantla, S. E. Boone, M. El-Ashry, D. Young, "Continuous polymer nanofibers by extrusion into a viscous medium: A modified wet spinning technique", Applied Physics Letters, vol. 88 no. 7, 2006.
10. J. Barrons, D. Young, B. R. Ringeisen, D. D. Dlott, D. Krizman, M. Darfler, “Printing of Protein Microarrays via a Capillary-Free Fluid Jetting Mechanism” Proteomics vol, 16 no, 5 (2005) 4138-4144.