Building on the Elograph, Hurst continued to refine the technology, first for a transparent screen and later for the groundbreaking touchscreen he debuted at Knoxville, Tennessee's 1982 World's Fair - with an interactive display at his booth.

Even amid the fair's future-tech theme, it was a showstopper and unlike anything the public had seen, much less interacted with in person. Known as a resistive touchscreen at the time, versions of this then-nascent yet highly innovative technology eventually became commonplace, but it didn't happen overnight.

Traversing a treacherous chasm between laboratory and marketplace

Breakthrough ideas like Hurst's touchscreen technology often take surprisingly long routes through history before becoming industry standards or even achieving common recognition. As with other lab-based discoveries in complex fields like quantum or nuclear technologies, the gap between idea and marketplace success can be both intimidating and difficult to navigate. Sometimes called the "valley of death," the gap illustrates the obscurity many technologies drop into after failing to navigate this major transition.

Along with formidable scientific discovery and a dose of good luck, lab-based inventions often need a little extra something to break through into the marketplace - a difficult-to-define secret sauce comprised of equal parts savvy business acumen, patience, dogged determination and the "soft" skills of simply relating to a wide variety of people with grace and ease - all of which Hurst had in spades.

"He grew the Oak Ridge Elo operation to more than 200 employees in the 1980s and made Elo the leading supplier of touchscreens for restaurant and point-of-sale systems that transformed those fields," said Warmack. "Late in his career, I had the privilege of teaming with Sam to develop new, multitouch-capable designs and developed a real appreciation for his gentle genius."

In the case of his touchscreen tech, it took decades, but by now, elements of this brainstorm have ended up in most of our pockets (and across the retail, banking and other industry landscapes) to redefine computer/human interactions. Starting at ORNL, Hurst's work led him to found multiple businesses that still impact science and technology-related industries today.

Companies Hurst founded include:

• Elographics (1971, a touchscreen industry leader now known as Elo)
• Atom Sciences, Inc. (1981, resonance ionization laser tech/DNA diagnostics, etc.)
• Pellissippi International (1987, microdosimetry, noble gas/optical detectors, etc.)
• Consultec Scientific (1990, radon detector/instrument stimulator devices, etc.)

Hurst passed away in 2010, a few years after the iPhone debuted but before touchscreens had achieved today's overwhelming ubiquity. While Hurst's colleague and ORNL co-inventor Bruce Warmack doesn't recall particular conversations, his insights into Hurst's approach offer valuable perspective, backed by first-hand experience.

"Sam didn't dwell on the past," said Warmack. "He was relentlessly forward-looking, focused on new methods and features that could open new paradigms - imagining touch sensing on everything from coffee cups to clothing - to make the world more interactive and responsive. Even as touchscreens matured in the early 1990s, we attempted to push the technology further, leveraging advances in computer chips and securing four patents, including one method for multitouch - a capability that is now ubiquitous but was novel at the time."

Community building: Laboratory, university, industry

Along with his colleague Jim Parks, who became its director, Hurst formed the Institute of Resonance Ionization Spectroscopy at UTK, which actively collaborated with ORNL to focus on techniques for detection and analysis of single atoms. The institute awarded graduate students in promotion of related, international research between 1985 and 2001.

"By the 1970s, the Health Physics Division was the first ORNL research division to develop ongoing ties with the Physics Department at UT, resulting in joint research projects and graduate students working on dissertation research at ORNL," said Riedinger. "Now this is commonplace, but this was a leading direction for the UT-Oak Ridge partnership in the 1960s and later."

Consistently recognized by universities, professional societies and industry organizations throughout a long and distinguished career, Hurst also amassed an impressive collection of academic, scientific and business-community awards, and his companies bolstered the East-Tennessee community with hundreds of jobs.

Hurst's impactful legacy, felt far beyond his many creative scientific inventions and achievements, is particularly evident today in the productive, enduring and symbiotic ties he helped establish between UTK and ORNL. This now robust partnership also helped build East Tennessee into an innovation corridor and a center for economic development that continues to thrive.

"In 1963, UT received a grant from the Ford Foundation to bring Oak Ridge researchers into part-time roles at UT, the first step in developing a Joint Faculty program that is now an important part of faculty recruitment for both UT and ORNL," said Riedinger. "Sam was one of the eight such initial appointments to be a Ford Foundation faculty member in the Physics Department, so he was a leader - not only in research and entrepreneurship - but also in developing the close ties between UT and ORNL."

Curiosity and character

Beyond his indefatigable curiosity about the world - which informed his dedication to teaching, scientific research innovation and career-long efforts to continually cultivate a fruitful partnership between UTK and ORNL - Hurst was also genuinely interested in everyday people and what made them tick. His sincere approach to preserving kind, respectful and thoughtful dialogue was lost on no one, and it invariably brought people of wildly diverging perspectives together in pursuit of greater understanding.

"Sam had a lifelong interest in how advances in science and technology affect society," said Warmack. "With Rufus Ritchie, he co-founded the Forum on Science and Religion, a popular gathering where several dozen scientists, clergy and other voices met regularly for respectful, substantive debate. The forum consistently brought together diverse viewpoints."

Today, Hurst is recognized among ORNL's most accomplished inventors on the wall of plaques in Building 4500N, a testament to the lasting impact of his contributions to science, technology and industry.

UT-Battelle manages ORNL for DOE's Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit https://energy.gov/science. - Chris Driver