Four alumni from Georgia Tech’s College of Engineering are leaders at the Department of Energy’s Oak Ridge National Laboratory.

The demand for sustainable energy solutions has never been greater, as concerns about climate change deepen and the world’s population continues to increase. People need access now to clean, sustainable energy for their homes and for transportation, energy that can be generated continuously, reliably, and cheaply.   

This was all the motivation that four alumni from Georgia Tech’s College of Engineering —  who are leaders at the Department of Energy’s Oak Ridge National Laboratory (ORNL) – required to spearhead a revolutionary solution to the ever-growing energy conundrum. ORNL’s Johney Green, Roderick Jackson, Lonnie Love, and Brian Post led the innovative thinking that went into the Additive Manufacturing Integrated Energy, or AMIE, project, pairing a 3D-printed house and vehicle to bring about a feasible solution to a global energy crisis. 

When unveiled in 2015, media around the world carried the AMIE story with headlines like: “A Solar-Powered-Home and Hybrid-Car Duo that Work in Tandem to Store and Use Energy” and “This Energy-Sharing Solar House and Hybrid Car Are the Ultimate Off-The-Grid Fantasy.” The accompanying photo revealed a black vehicle parked next to a sleek white structure, an odd couple indeed. 

AMIE features a host of brand new technologies all rolled up into one. About 20 industrial collaborators, including the DOE’s Office of Energy Efficiency and Renewable Energy, the architecture firm Skidmore, Owings, and Merrill (SOM) LLP, and the University of Tennessee’s College of Architecture and Design worked simultaneously on the project, which is a testament to the efficiency and success of a cooperative endeavor.

Think Big, Dream Bigger
Johney Green (Ph.D. M.E., ‘00) is director of ORNL’s Energy and Transportation Science Division, a role in which he provided primary executive oversight on AMIE’s development. In other words, Johney had quite a load to carry, but he wouldn’t have had it any other way. His big take-away on AMIE is the level of interest it generated among all that saw it. 

“Quite often you’re in the middle of your work and can’t fully appreciate what you’ve done,” Johney said. “Seeing what we accomplished and the reaction people have had to it has exceeded my expectations in terms of the importance of what we did.” Johney said he encountered reactions from shock and awe to downright disbelief and surprise that a national lab could do something so fast on that scale. 

AMIE was on display at the 2016 International Builders’ Show where thousands of people came by to see it. And it was featured on DOE’s webpage 14 Exciting Things Coming Soon from the National Labs. “It can’t get much better than that,” said Johney. 

Roderick Jackson (Ph.D. M.E. ‘09) imagines lots of possibilities. As technical lead for the project, he was involved in every aspect of its development, leveraging his proficiency as group leader for ORNL building envelope systems research. Roderick believes AMIE answers a lot of “what if” questions in both construction practices and energy generation. What if parked cars could power their surrounding buildings? What if we didn’t build houses the same way we have constructed them for centuries? What if we could build new homes in a fraction of the time? What if the 2.3 billion people in the world living without reliable electricity had access to a clean renewable source of energy? AMIE demonstrates that all these things are within reach.

“The most challenging part of the project was also the project’s biggest asset — diversity,” said Roderick. The team was comprised of architects, building scientists, microbiologists, engineers, and scientists from other disciplines, including SOM, the architecture firm who designed the house. 

“Instead of trying to get everyone to see the project from the same perspective, the different camera angles as viewed by each team member fostered an ‘intellectual disruption’ that allowed us to truly challenge assumptions and the status quo,” said Roderick. “The diversity within the team required each member not only to consider integration with other technologies and systems in AMIE, but it also introduced new design and operating constraints that required a new way of thinking.” The result was something far more innovative than any one discipline could have accomplished alone.      

It takes a “Wow!” moment to soak in the fact that both the house and vehicle are 3D printed. That takes a pretty large polymer 3D printer and, conveniently, ORNL has the world’s largest. Known as the Big Area Additive Manufacturing (BAAM) system, it’s the first additive system to take on industrial scale manufacturing.  

Lonnie Love (Ph.D. M.E., ’95), group leader for ORNL manufacturing systems research, explained that most additive systems are small, slow, and expensive, but using the BAAM system enabled researchers to build a proving ground to scale very rapidly. One of the most amazing things to Lonnie was the sheer volume of material BAAM could process. 

“We went through 25,000 pounds of material in one month,” Lonnie said. “We had tons of raw feedstock entering the facility in the morning and tons of product leaving at night using one machine.” But as mind-boggling as the amount of material processed may be, Lonnie stresses that AMIE’s biggest contribution not only to the field of engineering, but also to the world, is the integration of energy for transportation and buildings with bi-directional wireless power transfer.  

ORNL leads the field on development of level 2 bi-directional wireless power transfer. This method of charging electric vehicles is both a fast and efficient alternative to plug-in charging. The AMIE project uses a hybrid electric natural-gas-fueled vehicle to provide power to a home via its battery and in turn, the home’s energy storage system can wirelessly send power back to the vehicle’s battery —  the first demonstration of this technology. Imagine the possibilities.

Brian Post (Ph.D. M.E., ’13) works with Lonnie in manufacturing systems research, where he was part of BAAM’s development. He combined his academic background in robotics with additive manufacturing to develop the robotic technologies that built AMIE. He particularly likes the flexibility of additive manufacturing and its ability to print non-traditional structures. 

“The first design we got from SOM was the traditional square building with corners,” Brian said. “We went to the architects and told them they’re not limited to squares and corners and asked what they would like to do that’s different. That’s how we got the elegant curves in the AMIE structure.” 

Brian spoke of the newness of additive manufacturing technology relative to what it has accomplished thus far. “It was only about three years ago that printing at such a large scale became possible,” he said. “Prior to the BAAM process, most printers had really small work spaces about the size of a shoebox.” Jump forward to the present day, and the technology can print a small house and car. 

“We finished the development of the 2nd generation BAAM machine, the largest of its kind, only a month before we printed AMIE,” added Brian. 

Little House on the Printer
AMIE’s 210-square-foot house has a glass entry, integrated lighting, a pull-out bed and an all-in-one micro-kitchen with a touch screen console and a full array of appliances (including a dishwasher).  Its appeal is credited largely to its potential for greater functionality, durability, and energy efficiency. 

When AMIE’s researchers mention rapid innovation and construction, they’re talking about weeks. From the start of the printing process to the unveiling of AMIE last September, the project took about less than nine months. The collaborative nature of the work was key to pushing the envelope. Engineers worked daily with architects and researchers to redesign or alter some aspect of the project that wasn’t going to perform at an optimal level. Instant feedback and a quick response to alter or adjust the plans greatly sped up production.  A team that included engineers and staff from Clayton Homes assembled the printed pieces of the house in just three weeks.

After experimenting with several types of materials, the research team settled on a thermoplastic polymer (ABS plastic) and added 20% carbon fiber to strengthen the printed sections. Between the structure’s inner and outer walls, they installed vacuum-insulated panels, which are seven times more energy efficient than traditional wall insulation. Smaller details like recessed windows and the streamlined, reflecting white exterior add to the energy efficiency of the home. The house is connected to the grid but also has a rooftop solar photovoltaic system paired with secondary use batteries to provide renewable power generation and storage. 

Hammers and Nails and Saws, Oh No!
Additive manufacturing for home construction can revolutionize certain aspects of the building industry because each component of the structure can be produced to exact specifications. 3D printing potentially uses less material and produces more complex shapes that could make the structure sturdier. The process also uses less energy and generates less to zero waste. Also, using additive manufacturing techniques in certain kinds of development and production can help companies get their products to the market more quickly than conventional manufacturing methods. New design concepts can be printed and evaluated almost immediately; the designers can make adjustments on the fly. 

A U-Turn in Car Manufacturing
The 3D-printed utility vehicle (affectionately dubbed a “PUV”) shares energy with the house via ORNL-developed wireless power transfer technology. The hybrid natural gas-powered vehicle can power the house when sunlight is low, electricity from the grid is interrupted, or the house’s battery is depleted. Likewise, the home’s battery mounted under the porch supplies energy to a charging pad outside. The PUV is parked over the wireless power transfer pad so its battery is aligned directly above the pad to recharge, thus eliminating the conventional infrastructure normally required. An intelligent control system can transfer energy via wireless power transfer back and forth between the house and vehicle where it’s needed most — from solar or battery power — while the PUV is parked.

Driven by Discovery
With their success at ORNL and the sheer enjoyment of developing AMIE, the four alumni seemed to have found their respective callings. It shows in their work, if not in their words. 
 
For Johney, his career as a mechanical engineer began (as it does for many budding engineers) by fixing and assembling different items for his mother. And because he excelled in science and math, his teachers and guidance counselors pointed him in the direction of engineering. 

“I love heat transfer; I love thermodynamics; I like it all. My passion for those topics made mechanical engineering a perfect fit for me” said Johney. 

He came to Georgia Tech as a graduate student after being invited to attend the school’s very first Focus event in 1992. This is one of the nation’s finest programs for raising awareness of graduate education among the best and brightest underrepresented minority students. Johney credits Dr. Bill Wepfer for steering him toward graduate education, inviting him to attend the Focus event and paying for his travel expenses. Dr. Wepfer also identified National Science Foundation funding to help him pursue his doctoral degree. 

“I owe a lot to him. He’s a great man.” said Johney.

Georgia Tech College of Engineering Dean Dr. Gary May, who currently serves on the Executive Committee of the National GEM Consortium was also one of his role models. Dr. Green is a GEM alumnus and also serves on the Executive Committee of GEM. In 2015, Johney was elected fellow of SAE International, the professional society of mobility engineers.

Roderick became well-versed in conventional building methods as a kid helping in his father’s construction business and thinks about how those methods can be improved. “We have been building houses the same way for centuries,” he said. “Technology has enabled new ways of manufacturing in most other industries. Perhaps some of the additive approaches to manufacturing we have demonstrated with AMIE will inspire new and better ways to build houses in the future,” he said. Roderick points out that AMIE is only the beginning, a prototype that has already provided lessons learned for improvements and further refinement. (“AMIE 2.0” is on the drawing board now.)  

Lonnie likes being a scientific entrepreneur and working with like-minded individuals. “It’s exciting to identify choke points in a technology that are preventing it from growing exponentially, and then building a team to solve the problem,” he says. His team has partnered with material scientists and found that, by using the right material, the process can be scaled by many orders of magnitude. 

As for his days at Georgia Tech: “I had two great mentors: Wayne Book and Steve Dickerson. They both played a big part in forming my career, both directly and indirectly.” 

Engineering is a rapidly changing field and that’s one reason Brian enjoys his work so much. “I always wanted to do something that is constantly changing,” he says. “Every day I get to make something different and new and I’m glad to be a part of that work.” Brian had several mentors starting in high school with his physics teacher, who was an engineer himself. He confirmed Brian’s growing interest in engineering as a career choice. He also worked with Bill Peine as an undergrad in surgical robotics. “It was a great experience because I got to help build different types of robotic systems.” As an intern at ORNL, Brian worked with Lonnie and “fell in love” with all the different types of robotic systems. And Dr. Wayne Book at Georgia Tech helped steer him into the position and work he now has at ORNL.

Editor's note: Johney Green recently accepted a new position as assistant lab director at the National Renewable Energy Lab.

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