Stephen Killough inspects the metal cones that focus microwaves at a board to detect moisture inside, part of the test setup for a new tool to find moisture in building walls. Credit: Carlos Jones/ORNL, US Dept. of Energy
Stephen Killough’s office at the Department of Energy’s Oak Ridge National Laboratory is a window into four decades of technology -- and a crash course in connections wired by electronics, creativity and humor.
Coils of cables festoon shelves cluttered with artifacts and inspiration: cruise control radar, a fake skull, a ring stacking toy, an early handheld Motorola walkie talkie with circuitry Killough designed, a pewter fairy, and generations of boxy radio frequency instruments. A bike crammed in the corner is ready for quick cafeteria trips. “My mom bought this Peugeot for me in 1974,” said Killough, a researcher in the Radio Frequency and Intelligent Systems group. “I like to keep old stuff running.”
After more than 43 years at ORNL, Killough is inspired by old gear while pioneering new technology. He is known across the lab for his expertise in radio signals and electronics, which he applies to challenges in national security, industrial and nuclear controls and building efficiency. But Killough is also known far beyond the lab for inventing a multi-directional wheel platform that bears his name. (It has its own Wikipedia page.)
Killough invents at work. He invents in his free time. His “SpyBike,” an after-hours project, could have emerged from the lab of James Bond’s quartermaster Q. It folds into a briefcase at the bus or the office. Yet despite its name, the scooter was designed to solve a practical problem – a theme among Killough’s favorite projects.
For example, he recently helped create and test a radar tool for finding moisture inside building walls without damaging them. A team led by ORNL’s Philip Boudreax developed the technology, which uses microwave reflections and an ORNL-developed algorithm to map the location and extent of dampness before it causes rot and health hazards. “It’s great to go out with a bang,” said Killough, who plans to retire later this year. He showcased the tool’s testing setup in one of his labs, expressing hope that a manufacturer will license the technology so homeowners can buy it.
As with many ORNL projects, Killough contributed his expertise in understanding energy waves and creating prototypes. That role dates to his first ORNL internship while earning his master’s degree at the University of Tennessee: Killough designed a circuit to measure changes in voltage waveforms at electrical outlets, which can provide an early warning of approaching grid failure.
Based on Killough’s master’s thesis on speech recognition, ORNL hired him in 1983 as a technical associate to design a voice command system for a set of robotic manipulator arms. “It was a very, very early generation of Alexa,” Killough joked, but it enabled scientists to safely study highly radioactive materials from a distance. Killough went on to convert analog robots to computerized controls and to design new mobile robots, both for factory settings.
Exploring robot mobility possibilities led to inventing “the Killough platform” for universal wheels, a new approach to letting robots move sideways as well as forward and backward. A local entrepreneur saw its potential for wheelchair applications and asked Killough to build a prototype. That earned a patent, won an R&D 100 award and a Discover Magazine award, and was showcased for the public to try at Walt Disney World in Florida.
However, Killough noticed that disabled Disney visitors dismissed the wheelchair design. He wondered why. “I took it home and drove it around my house all day to try to find something that only this chair could do, and I couldn’t,” he said. Instead, he realized a wheelchair moving sideways is traveling at its broadest dimension, making it tougher to fit through tight spaces.
A thinker as well as a tinkerer, Killough relentlessly questions his assumptions about what inventions to pursue. “You’re kind of picking winners and losers,” he realized. “In this case, do people who are handicapped accommodate society, or does society evolve to accommodate handicapped people? There should be more wheelchair ramps and elevators instead of overly-complicated wheelchairs.”
In the last decade, Killough has instead tackled electronics solutions in fields ranging from consumer goods to national security. He built a prototype for radio frequency-hopping technology and developed software algorithms to encrypt analog radio signals, all to foil hacker interference in communications. For home consumers, Killough joined engineering teams that developed a refrigerant leak sensor and a screen-printed, peel-and-stick thermostat that transmits information to heating and cooling systems without wiring.
After retirement, Killough hopes to devote more time to an old hobby: Refurbishing historic train engines and cars through the Southern Appalachian Railway Museum based in Oak Ridge. In the early 2000s, the group ran a restored excursion train on old tracks at the former K25 gaseous diffusion plant, where uranium was once enriched for weapons. Killough served as master of ceremonies for the train rides, using humor and quirky details to intrigue visitors with the history of the train cars, nuclear energy, and the World War II roots of Oak Ridge.
Whatever’s next, Killough will still be getting a charge out of engineering and asking questions. When several early career researchers waved goodbye after leaving his lab, Killough called after them, “Here’s the most important question – Did you have fun?”
