For release August 24, 2005
NEW LASER MATERIALS EXPERT AT SPACE INSTITUTE SEES UTSI AS ‘GATEWAY’ TO ADVANCED MATERIALS
Dr. William Hofmeister, an expert in laser materials processing and materials science, wants to see The University of Tennessee Space Institute become “Middle Tennessee’s gateway to advanced materials.”
Hofmeister, a new full-time research professor at UTSI, also says the Institute’s collaborations with Oak Ridge’s Center for Nanomaterials Science, UT’s Materials Science Department, and two of Vanderbilt’s research facilities will “keep UTSI in touch with the latest in nanomaterials.”
“Dr. Hofmeister is a tremendous asset for the Institute, especially at this time when we are emphasizing materials processing and research,” said Dr. John E. Caruthers, UT associate vice president and UTSI’s chief operating officer.
Hofmeister was a research professor at Vanderbilt University for nearly 20 years where he worked on a variety of materials related topics with the NASA Center for Space Processing, Diamond Microelectronics Group, Vanderbilt Institute for Nanoscale Science and Engineering (VINSE), and the Vanderbilt Institute for Integrative Biosystem Research and Education (VIIBRE).
He conducted research on nucleation and solidification, synthesis of diamond films and carbon nanotubes for field emission, and fabrication of hybrid bio-silicon devices for sensors and medical research.
A past chairman of the Solidification Committee of TMS, Hofmeister has published more than 90 papers and edited four books in the field of materials science.
Hofmeister is no stranger to aeronautics and aerospace. He obtained his private pilot’s license at 17 and began his career in materials science at Pratt-Whitney Government Products Division where he worked on F-100 turbine engine development for the U.S. Air Force and the Defense Advanced Research Project Agency.
Professor Hofmeister participated in three space flight experiments sponsored by NASA to study effects of fluid flow on nucleation. The space flight experiments were conducted by “telescience” operation in low earth orbit using modeling and simulation software that Hofmeister developed for the experiments. He was principal investigator for the TEMPUS Incandescence Measurement Instrument Project, which designed and implemented an infrared pyrometer on the existing space lab flight hardware. He is now working with NASA Langley to develop free-form fabrication using an electron beam process for future NASA missions.
In studying solidification kinetics, Hofmeister pioneered the use of ultra high-speed thermal imaging in the observation of solidification at high undercooling. He developed a thermal imaging array to track solidification at 50 meters per second. He also used this equipment to study the impact, spreading, and solidification of molten metal drops. Hofmeister was the first to report the ability to form superconducting materials directly from the undercooled melt.
“John Sumgeresky, a colleague of mine from Sandia National Laboratory, saw a presentation of the thermal imaging work and asked if it could be applied to the Laser Engineered Net Shaping (LENS ) process he was working on in Albuquerque,” Hofmeister recalled. This conversation led to the development of thermal imaging tools for scientific understanding of the direct metal deposition processes. Hofmeister then used these tools for closed loop feedback control of the process, significantly increasing the uniformity of deposited materials.
“Thermal imaging and vision-based process control will enhance UTSI’s Laser Induced Surface Improvement process,” says Hofmeister. “We plan to make UTSI a major player in the area of Laser process control.”
The professor also has experience with nanotechnology. He holds a patent for carbon nanotube catalysts used in field emission and developed a nanopourous membrane for the planar perfused bioreactor that VIIBRE uses in cancer research.
Dr. William Hofmeister shows Dr. John Caruthers a hollow airfoil created with a process that Hofmeister helped develop at Sandia National Lab. The process uses high power lasers to melt and solidify metal powders into 3 dimensional shapes.
– UTSI Photo