Home | Archive | Subscribe

When John Woollam came to the University of Nebraska–Lincoln in 1979, he hoped he would be engaging in dynamic research. Little did he know that research would take him further than he ever dreamed. From the classroom to the creation of his own company, Woollam has combined teaching, research and outreach to unravel the minute mysteries of surfaces. Woollam, the George Holmes Distinguished Professor of Electrical Engineering and Professor of Physics and Astronomy, brings enthusiasm to both his classes and his research, blending the classroom with the laboratory by involving his students in his research and providing them with practical experience. His work has impacted the University and the state of Nebraska. It has even touched the stars.

Woollam came to the University after 13 years with NASA. Upon his arrival, he agreed to take over the work of Nick Bashara and Rasheed Azzam, College of Engineering & Technology professors who began ellipsometry research at the University during the 1960s. It wasn’t quite the turn he was expecting but Woollam readily embraced the idea of ellipsometry, an optics technique that uses the reflection of polarized light to perform diagnostics on material surfaces such as thin films. “I became interested because the opportunity presented itself,” he said.

Surfaces, such as thin films and coatings, often have unique measurement problems that require microanalysis. Researchers need to know about the composition, thickness, uniformity and functionality of these materials, as well as any defects or contamination. Several instruments used to address these questions and innovations, such as ellipsometry, provide a method of measurement that makes the impossible possible. Today, Woollam’s laboratories are equipped with the latest technologies in microanalysis, but when he first arrived at the University, the circumstances were quite different.

“We could make the research we were doing work, most of the time,” Wollam said. “But it didn’t really work well enough. We lacked reliability.” The instrumentation also lacked automation. When Woollam began doing ellipsometry, he used IBM punch cards for data acquisition, calculations and approximations and had to wait overnight to receive results. The work was labor-intensive and time consuming. Automation has made materials analysis infinitely faster and allowed Woollam and his engineers to makegreat contributions to the field by providing new software and mathematics to assist in data processing.

The continued desire for better tools translated into the founding of the J.A. Woollam Company in 1987, the only manufacturer of research ellipsometers in the world. “There was a demand for the product, even before we started the company,” said Woollam. “In fact, we made some instruments before starting the company, then discovered we could market them.”

What began as a venture with Woollam and a handful of engineering graduates has evolved into a company with more than forty employees, 35 patents with 20 in process, and annual revenues of more than $15 million. The company maintains an ongoing relationship with the University through technology transfer, supported research, and the hiring of graduates from all fields within the University, including the humanities. In fact, all but six current employees of the J.A. Woollam Company are Nebraska natives and University graduates.

In laboratories in the Walter Scott Engineering Center, Woollam continues to perform materials analysis, with most of his current work focusing on optical coatings. For the past 24 years, Woollam also has researched coatings and surfaces that will withstand the space environment for NASA. “We are researching optical coatings right now, but ten years ago we were doing graphic fibers for lightweight electrical conductors in space,” said Woollam, explaining his flexibility when it comes to the direction of his research. “Our orientation revolves around the very specific technology needs of the entities that provide us with research funding.”

Optical coatings control the amounts of light that are reflected or transmitted whenever light is incident on the boundary between two media. They can be used in telecommunications to set up multiple channels of coded information simultaneously, while selecting out certain frequencies. They can also be used for temperature control in space through energy conversion by absorbing light from the sun and converting the heat that is absorbed.

Woollam and his research team carefully control the optical and physical properties of the coatings. Then they use their instruments to perform diagnostics to ensure the coatings have been made correctly and function as they should. Using a variety of instruments provides the researchers with different aspects of these surfaces. The instruments work in harmony to create a complete picture, which enables researchers to duplicate coatings and other surfaces consistently. It also provides them with a greater understanding of the materials they are working with.

Some of the equipment used includes multiplex and compound sputtering systems, an electron beam evaporation deposition system, a low earth orbit simulation chamber that simulates a space-like environment, several different types of ellipsometers, variable temperature chambers, various spectrometers for chemical analysis, an atomic force microscope that maps sample surfaces to the atomic scale both vertically and horizontally, a step tester that quickly measures heights and roughness, as well as an extensive computer analysis network that is used to analyze the data provided by the army of instruments.

In the laboratory and the classroom, Woollam works with both undergraduate and graduate students and fosters long-term relationships. By the time his students graduate, they know how to operate, tune, calibrate and align the instruments they use and are more valuable to partners in industry because of that rarified skill set. “Research is a very important teaching tool. The things students learn in class are applied in the lab and vice versa,” Woollam said. “Research also keeps me learning about new concepts, techniques and fields of research. We have to make new contributions and I can bring the things I’m learning to the classroom and put them to use immediately.”

Now, as Woollam has established his expertise with optical coatings, he is looking to the future, and biotechnology—particularly biomedical applications of thin films. Potential biomedical applications of thin films could include the study of proteins on surfaces like stents, drug delivery, and tissue engineering. “I have a great deal of experience in inorganic materials.” Almost half of his current research is on the biological side and he has deliberately hired a polymer chemist as a graduate student, as well as Ph.D. student in chemical engineering. It is the biggest change his research has undergone. “My new work is to integrate inorganic materials with organic ones,” said Woollam. “Imagine being able to use visible and infrared ellipsometers to do fundamental studies on what adheres to the stent material and what doesn’t.”

This begins a time when Woollam looks inward to the mysteries of the human body, as well as upward toward the universe.