David Stein, PhD

• Ph.D., Materials Science & Engineering, University of Pennsylvania, 2011
• M.S.E., Materials Science & Engineering, University of Pennsylvania, 2006
• B.S., Materials Science & Engineering, Carnegie Mellon University, 2004

Vice President of R&D, Ionic Water Technologies, 2021 – present

Greentech start-up focusing on PFAS removal and desalination technologies

Running project to commercialize PFAS adsorbant regeneration technology

Government center for improving manufacturing in Central Ohio

Evaluated technical needs of manufacturing partners and developed projects to satisfy those needs in a cost-effective manner to improve overall competitiveness of partner

High-end manufacturer of hard and superhard materials

Developed new products in novel form factors for new application spaces in metal cutting and road milling. Guided developed products to commercialization including training, documentation, and process improvements to meet production yield requirements.

• Developed three new products that met performance and yield requirements
  • Developed technique for creating layered products to minimize thermal expansion mismatch using gravity and slurry viscosity to optimize thickness at point of maximum stress along interface
• Managed the transition of three products from engineering to operations including training of manufacturing associates and documentation of processes
• Redesigned cell used in production of a product family to reduce complexity and cost, which reduced operator touch time and improved yield.
• Advanced company knowledge of sintering mechanisms through evaluation of additives to existing products, leading to next-generation product development.

Development Scientist, Eos Energy Storage, 2012 – 2014

A start-up developing grid-scale battery solutions for load-leveling applications

Led cathode chemistry and design development from lab-scale experiments to the first large-scale integrated prototype for third-party testing. Cathode performance contributed to the battery chemistry reaching key cost, longevity, safety, and efficiency metrics ahead of large-scale testing.

• Developed and directed on-time production schedule of prototype battery for initial third-party testing with key public utility partner.
  • Developed documentation for this battery to capture the current state of development.
• Trained 10+ technicians in cathode production and automated quality control check to alleviate production bottleneck ahead of a critical production deadline of prototype battery.
• Provided key technical data and interpretation to promote technology to current and future investors.

Postdoctoral Researcher, University of Pennsylvania, 2011

Advisor: Peter K. Davies

In a short-term appointment (6mo), quickly produced bulk samples of novel photovoltaic chemistries and characterized cation valence and oxygen content by TGA to fulfill requirements for publication.

• Work published in Nature (see below)

Graduate Research Assistant, University of Pennsylvania 2004-2011

Advisor: Peter K. Davies

Dissertation: Structure and Properties of Bi-containing Mixed A-site Perovskites

Explored perovskite chemistries to stabilize bismuth in a tetragonal perovskite form as a method for improving ferroelectric and piezoelectric properties. Discovered a chemistry that enhances the tetragonality of the structure beyond PbTiO Also discovered a class of chemistries with novel ‘persistent tetragonality’ behavior as observed by dielectric response. Determined the relationship between B-site chemistry and this behavior.

Undergraduate Research Assistant, Carnegie Mellon University, 2001-2004

Advisor: Paul A. Salvador

Explored the fabrication of freestanding particles for photocatalysis by synthesizing multi-layer epitaxial thin films using pulsed-laser deposition with layers chosen for their photo-absorption and catalysis properties, plus a sacrificial layer intended to be etched away. Structure and orientation were characterized with X-ray diffraction and particles were freed from the substrate via etching and collected by filter.

Perovskite Oxides for Visible Light Photoferroelectrics and Photovoltaics.

Grinberg, I., West, D. V., Torres, M., Gou, G., Stein, D. M., Wu, L., Chen, G., Gallo, E. M., Akbashev, A., Davies, P. K., Spanier, J. E. and Rappe, A. M., Nature. 2013. 503: 509.

Effects of B-site chemistry on BiFeO₃-containing enhanced tetragonality systems.
Stein, D. M., and Davies, P. K., Applied Physics Letters. 2011. 99(18): 182907.

Multiple dielectric transitions in the PbTiO₃-Bi(Zn_1/2Ti_1/2)O₃-Bi(Mg_1/2Ti_1/2)O₃ system.
Stein, D. M., Grinberg, I., Rappe, A. M., and Davies, P. K., J. of Appl. Phys. 2011 110(7): 074110.

Enhanced tetragonality in (x)PbTiO₃-(1-x)Bi(B’B’’)O₃ systems: Bi(Zn_3/4W_1/4)O₃.
Stein, D. M., Suchomel, M. R., and Davies, P. K., Applied Physics Letters. 2006. 89: 132907.

• Oral: Persistent Tetragonality in Bi-containing Perovskite Oxides. Presented at the North American Thermal Analysis Society Annual Conference (2010), Philadelphia, PA.

• Poster: Persistent Tetragonality at High Temperature in PbTiO₃-Bi(B^IB^II)O₃ Solid Solutions. Presented at the Fundamental Physics of Ferroelectrics Workshop (2009), Williamsburg, VA.

• Oral: Persistent Tetragonality at High Temperature in Ferroelectric Perovskites. Presented at the Materials Research Society Fall Meeting (2008), Boston, MA.

• Oral: Effects of Chemistry on the Structure and Properties of PbTiO₃-Bi(B^IB^II)O₃ Solid Solutions. Presented at the Fundamentals Physics of Ferroelectrics Workshop (2007), Williamsburg, VA.

• Peer review for IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control (2008)