Post works on large-scale additive manufacturing at the MDF, a DOE Office of Energy Efficiency and Renewable Energy User Facility at ORNL. “A lot of that comes down to systems—making the machines do what humans want, from the hardware and software to embedded controls,” he said.
Post has been involved in nearly every large-scale printing project at the MDF, including multiple vehicles, a submersible, a tiny house, an outdoor pavilion, an excavator, and molds for manufacturing appliances, airplane wings, and wind turbine blades. Currently, his team is working on a mold for a 35-foot catamaran and on a large-scale, laser-based welding system for titanium aircraft parts as part of the MDF’s formal, collaborative work with industry.
“We’re building things on a scale that not many people have ever 3D-printed—we have to think carefully about how to design each component and how to build it,” Post said.
For instance, in the early days of large-scale printing, students followed the materials extruder around on the printing platform using spatulas to manually flatten the printed surface and keep it in place. To automate that process, the team created a patented technology using a reciprocating platen to serve the same function. The researchers also devised their own slicing software, which analyzes computer-aided design models for the objects to be printed and then guides the extruder on the proper path.
Post grew up in nearby Powell, TN. His father, Wilfred “Mac” Post, is a retired ORNL environmental scientist who studied carbon cycles at the lab, and his mother, Susan Riechert, is a distinguished service professor in ecology and evolutionary biology at UTK whose specialty is arachnids.
“I always knew the lab was a place where interesting research was happening, and my parents enjoyed their work,” Post said.
Post went on to earn a bachelor’s degree in mechanical engineering at Purdue University. His interests widened as an undergrad during a summer internship with the robotics group at ORNL, where he worked with Lonnie Love, who now leads the Manufacturing Systems Research group at the MDF.
“I worked on human amplifying machines and omni-directional vehicles that summer, and it was instantaneous: I knew that’s what I wanted to do. I wanted to build incredible things that have a purpose and a mission,” Post said.
Love’s mentoring had a profound influence on shaping Post’s academic and professional career, Post noted. He followed in Love’s footsteps by continuing his studies at the Georgia Institute of Technology, earning both a master’s degree and a doctorate in mechanical engineering, specializing in dynamics, controls, and robotics.
“I knew there were three ways I could use my PhD,” Post said. “I could work in the private sector, where I would solve related problems that have a big impact on the company. I could go into academia, where I would dive deep in one area and focus on that for most of my career to reach a level of expertise.
“In the middle is the national lab,” he added. “Here I work on complex and interesting challenges, and I’m not doing the same thing forever. Every five years you reinvent yourself, figure out where the next stage of technology is going, and how you will fit in.”
Post’s doctoral thesis focused on control of long-reach, flexible robotic manipulators, specifically associated with the robotic arm on the space shuttle orbiter. When Post came back to ORNL as a postdoc, his techniques were immediately applied as the MDF developed a robotic arm for its first large-scale additive manufacturing printer.
Now as full-time staff, Post finds engaging with his own interns very rewarding and akin to teaching as he guides them in modeling and additive manufacturing research at the MDF, funded largely by DOE’s Advanced Manufacturing Office.
Post also lauds the collaborative nature of the work at the lab. “We’re pulling in people from supercomputing to help us run data analytics on printed parts. We’re pulling in materials scientists who have developed new aluminum alloys” such as the cerium-aluminum alloy recently licensed to Eck Industries. “And we’re bringing others, for example, who had the idea of printing rare earth magnets,” an achievement documented in Nature Scientific Reports.
“We have experts in almost every field who make this kind of manufacturing a possibility. We’ve been able to create a system of innovation here that’s incredible to be a part of,” Post added.
One of the next big research areas for the MDF team is designing a system to strategically deposit multiple materials to create more complicated components. “We might want to move from foam to a solid to continuous fiber, then discontinuous long fiber within a single part. Or in printing an engine, we might want to deposit rare earth magnet materials in specific areas,” Post explained.
These kind of revolutionary advances “are the reason why ORNL exists,” Post said. “We have great streams of knowledge that have grown here. The origin of the lab was in creating manufacturing infrastructure to make nuclear materials. Our robotics research grew out of a need to find better ways to handle nuclear materials.”
Post added that “there’s not much about my job I don’t like,” Post said. “We handle some of the most complex and interesting challenges ever seen in engineering, often with short timelines. We try to limit ourselves to one miracle per project, but that’s a rule we break consistently.”