Virginia Tech Mechanical Engineering Annual Report 2017 Annual Report | Page 11

E broad temperature ranges necessary for the extremes of space. Typical printable polymers start to lose their mechanical strength on average of 300 degrees Fahrenheit. This new polymer maintains its properties above 680 degrees Fahrenheit, the research team said. “We are now able to print the highest temperature poly- mer ever -- about 285 degrees Fahrenheit higher in deflection temperature than any other existing printable polymer. Additionally, our 3-D printed material has equivalent strength to the conventionally processed thin-film Kapton material,” Williams said. (The new material’s heat-resistant ceiling before degradation is about 1,020 degrees Fahrenheit.) “We can imagine this being used for printing a satellite structure, serving as a high-temp filter, or a high-temp flow nozzle,” said Williams, the Elec- tro-Mechanical Corporation Senior Faculty Fellow in Advanced Manufacturing Systems. “We can imagine using the wide geometric and microscale possibilities offered by 3-D printing to further improve existing designs – say, a more lightweight satellite, a filter that provides optimum/efficient flow, a nozzle with a designed flow path that allows greater exit velocity and efficiency.” A key early breakthrough in the project occurred in the laboratory of Timothy Long, a professor with the Department of Chemistry in the College of Science, and also the director of the Macromolecules Innova- tion Institute, located within Virginia Tech’s Institute for Critical Technology and Applied Science. Wil- liams is associate director of MII. There, Long working with then-post-doctorate researcher Maruti Hegde, now a research associate at the University of North Carolina at Chapel Hill, were exploring the possibility of making 3-D printed shapes from aromatic polymers such as Kapton. The researchers, along with a graduate student team, were able to derive the novel polymer synthesis design, allowing the polyimide to be 3-D printed. Williams’ lab, led by College of Engineering doctoral students Viswanath Meenakshisundaram of Bangalore, India, and Nicholas Chartrain of Westfield, New Jersey, then exacted the process for 3-D printing. “We chose a fairly ubiquitous high temperature and high strength polymer because we wanted to enable a rapid impact on existing technologies,” Long said, adding being able to create such 3-D printed mate- rials in any shape could serve a key market, such as the aerospace industry. Indeed, Long said companies have already shown early interest in the new material, which has a U.S. patent claim filed. The two teams spent a year testing the material’s performance in extreme heat and cold tempera- ture scenarios, and fine-tuning how the material is machine printed. Williams’ and Long’s work was recently published in the Advanced Materials Journal, under a fitting title: Processing the Nonprocessable. Williams and Long have collaborated on several projects involving 3-D printing. “At the end of the day, we are each other’s biggest cheerleaders,” Williams said of his work with Long’s lab in the College of Science. Long added, “We chal- lenge each other with how polymer structures must be invented, or reinvented, to enable 3-D printing. It is truly a partnership for innovation.”