Principal Investigator

Owen Hildreth

Owen Hildreth

Assistant Professor

Dr. Owen Hildreth is an Assistant Professor  in the Department of Mechanical Engineering at Colorado School of Mines.  He received his B.S. in Mechanical Engineering from the University of California, San Diego in 2002 and worked for five years as a mechanical engineer designing consumer products.  He returned to school in 2007 and, in 2012, received his Ph.D. in Materials Science and Engineering from the Georgia Institute of Technology under the supervision of Prof. C. P. Wong.  His Ph.D. research identified the mechanism for catalyst motion in metal assisted chemical etching (MacEtch) for applications in 3D nanofabrication.  Prior to his appointment at ASU, he was a National Research Council (NRC) postdoctoral fellow at the National Institute of Technology (NIST) where he continued his study of MacEtch and expanded into additive manufacturing using reactive inks.  His current research areas focus on additive manufacturing from the nanometer to centimeter scales, including Coulombic repulsion in ultra-nearfield electrohydrodynamic printing; mass transport, reaction kinetics, and interface design in reactive inks for stretchable electronics, photovoltaics, and microfluidic devcies; sensitization kinetics, microstructure evolution, dilution, and corrosion of metals fabricated using Powder Bed Fusion (PBF) and Directed Energy Deposition (DED) technologies.

Contact: ohildreth[at]mines.edu      Office: CoorsTek 214

 

Graduate Students

Steven DiGregorio

Steven DiGregorio

Steven DiGregorio joined the group in 2019 to pursue a Ph.D. after graduating from New Mexico Institute of Science and Technology with a B.S. in Mechanical Engineering. He is interested in microelectronics manufacturing, printed electronics, and transparent conducting electrodes. His research focuses on optimizing reactive silver ink composition and printing conditions for photovoltaic metallization.

Collin Miller

Masters Student

Collin joined the group in Fall of 2021 as a Masters student and is supporting research on printed reactive silver inks for photovoltaic applications, electrospinning transparent conductive electrodes, separating lanthanides, and printing metal alloys at low temperatures.

Pickles

Pickles

Lab Safety Dog

Pickles has taken over Fluffy’s job as Official Lab Safety Dog.  He is still learning the ropes, but he is doing a good job keeping us all in line.  Pickles enjoys hiding bones, eating bones, and inspecting bones for safety issues.

Alumni

Subbarao Raikar

Subbarao Raikar

Ph.D. Alumni

Subbarao Raikar graduated with his B.E. in Aerospace Engineering from Jain University.  He joined our group at Arizona State University as a volunteer in Fall 2017 and finished his Materials Science in Mechanical Engineering in 2018. He continued as a Ph.D. student when we moved to Colorado School of Mines in Spring 2018. Subbarao developed an entirely new, sulfur-based self-terminating etching process for Titanium alloys.  His Ph.D. focused on the corrosion response of metals in sulfur and iodine-rich environments. He successfully defended his Ph.D. dissertation (Development of Sulfur-Based Self-Terminating Process for Support Removal and Surface Finishing of Additively Manufactured Ti-6Al-4V) on August 17, 2022 and graduated with a Ph.D. in Mechanical Engineering from Colorado School of Mines.

Dr. Stephanie Prochaska

Ph.D. Alumni

Stephanie joined the Hildreth Group in 2019 after receiving a BS in Materials Science & Engineering from the University of Utah in 2014, and a MS in Innovation Management & Entrepreneurship from Brown University in 2015. She spent 4 years working in industry prior to starting her PhD and continued working full time as a Materials Engineer at the US Bureau of Reclamation throughout her time at Mines. Her work involved evaluating the effects of novel surface finishing processes on the fatigue and corrosion performance of AM metals.  Stephanie successfully defended her Ph.D. dissertation (Evaluation and Optimization of Surface Finishing Methods Towards Improving the Corrosion and Fatigue Performance of Additively Manufacturing Laser-Powder Bed Fusion Metals) in July of 2022 and graduated with a Ph.D. in Mechanical Engineering from Colorado School of Mines.

Avinash Mamidanna

Avinash Mamidanna

Ph.D. Alumni

Avinash Mamidanna joined our group in Fall 2014 to pursue his Masters degree. He continued on as a PhD from Summer 2015 and has been a part of the group ever since. He is from Chennai, India and he got his B.S. in Mechanical Engineering from Anna University, Madras. He is interested in understanding the kinetics of reactive ink systems and their applications as front contacts for low temperature photovoltaics.  He successfully defended his Ph.D. dissertation (Morphology Prediction of Reactive Silver Ink Systems) and graduated with a Ph.D. in Mechanical Engineering from Colorado School of Mines in 2019. He now works for Applied Materials in the Bay Area.

Christopher Lefky

Christopher Lefky

Ph.D. Alumni

Chris Lefky joined our group in Fall 2014.  He graduated with his B.S. in Physics and Mathematics from Creighton University.  His thesis focuses on understanding the microstructure and corrosion/dissolution of dissolvable metal supports for PBF and DED printing.  He successfully defended his Ph.D. dissertation (Corrosion and Sensitized Microstructure Evolution of 3D Printed Stainless Steel 316 and Inconel 718 Dissolvable Supports) in 2018 and graduated with a Ph.D. in Mechanical Engineering from Arizona State University.  He now works with additively manufactured materials in the Phoenix area.

Dr. Carolina González Gaitán

Dr. Carolina González Gaitán

Postdoctoral Researcher Alumni

Dr. Carolina González Gaitán received her B.S in Chemical Engineering from National University of Colombia, Bogotá in 2011. She moved to Spain to pursue her Masters degree at the University of Alicante where she continued on her studies and received her Ph.D. in Materials Science in 2016. Her Ph.D. research was focus on the functionalization of nanostructured carbon materials for their application in electrocatalysis and biosensors. She joined our group in December 2017 to work on developing and optimizing new reactive inks for photovoltaic applications.  This includes adjusting reactive ink reduction mechanisms, measuring kinetic parameters, and working with other group members to integrate these new inks into their processes.  She was instrumental in developing new reactive silver inks for photovoltaic applications. This included adjusting reactive ink reduction mechanisms, measuring kinetic parameters, and working with other group members to integrate these new inks into their processes.  She has since moved on into industry, but her impact on our work continues to this day.  We still call her silver reactive ink recipe the “Gaitan Ink” and it is still our top performer.

Connor Barnes

Connor started working with us in 2018 as part of a Computer Science Field Session to write a Swift-based wrapper for the NI-VISA framework, we called it SwiftVISA similar to pyVISA.  This worked so well that we hired Connor to write more applications supporting research projects and expand SwiftVISA to be a pure Swift implementation SwiftVISASwift.  Connor is a brilliant programmer and his contribution to our group will be felt for years to come,

Fluffy

Fluffy

Dog Research Assistant

Fluffy is the Official Lab Dog.  Often joining Dr. Hildreth at nights and on weekends, he makes sure the lab is kept neat and tidy.  However, he is not a big fan of being in the lab because, as he says, “Labs belong in the lab.  I’m a Great Dane.  I should be in the dane, not the lab.”  Luckily, he accepts his role as Official Lab Dog with stoic optimism as long has he gets the occasional treat.

Fluffy passed away in Summer of 2021.  We miss him and we have continue to honor his strong commitment to safety.

More Alumni

Meredith Heilig worked with us from 2019 to 2020 as Research Faculty.  She contributed to our self-terminating etching processes for copper and her preliminary experiments with iodine helped demonstrate an entirely new approach to post-processing 3D printed copper alloys.  She now works for the United States Department of Reclamation.

Sanaz Yazdanparast worked with us from 2020 to 2021 as Research Faculty.  She continued Meredith’s copper-iodine work and optimized our new self-terminating etching process for GRCop and copper alloys.

Kristopher Parker worked with use from 2018 to 2019 assisting Avinash and Subbarao on their reactive ink and dissolvable metal supports research projects.

Brian Zucker worked with us from 2015-2016 under FURI research grant on the sensitization kinetics and corrosion of dissolvable metal supports in PBF and DED printed materials.  After graduating in 2016 with is B.S. in Materials Science and Engineering he got a job at Titan Industries to 3D print titanium.

Yiwen Huang after defending his Masters thesis on reactive SiO2 inks he joined Prof. Yan Chen’s research group at ASU to pursue his Ph.D. in autonomous vehicle

Anoosha Murella worked with us from 2015-2016 on a NASA undergraduate research grant studying reactive copper ink systems

Alexander Kim worked with us in 2016 under a FURI research grant on ultra-nearfield electrohydrodynamic printing of SiO2 and Ag reactive inks. After graduating with his B.S. in Mechanical Engineering, he is now pursuing his M.D.

Galen Arnold work with from 2015-2016 under a FURI research grant on non-contact methods to precisely locate tip for ultra-fine electrohydrodynamic printing.  After graduating with his B.S. and then M.S. in Mechanical Engineering, he got a great job.