by Robin Roenker

photos by Mark Cornelison

For associate professor Mark Watson, as exciting as creating new materials is, one end-product is even more fundamental.

“When you think about research and teaching, of all our products, the most important ones are our students,” he began.

“In the end, whether they go on to be chemists in any professional sector (private, public, government, or academic), or executives, patent agents, technical sales reps, or whatever their career, we’ve empowered them for that future by providing an environment for their continued growth as independent researchers and problem solvers,” said Watson, who was awarded this year’s Young Investigator Award by the Kentucky Academy of Science.

Watson—who routinely leads hands-on chemistry experiments for elementary and middle schoolers at Lexington’s Explorium—feels he was selected for the KAS honor as much for his passion for teaching as for his scientific contributions.

In his classroom, he strives to create an environment that supports students’ independent curiosity.

“With an eye for the diversity of our student enrollment, I hope to cultivate the relative best, independent effort from all,” he said.

Watson takes that same teaching approach beyond UK’s walls. During sessions at the Explorium, he’s even shown six- and seven-year-olds how to carry out the same chemical reactions that his lab uses to make organic, glowing fluorescent polymers.

“They love it,” Watson said. “Their eyes just light up when they realize you trust them with real laboratory equipment.” 

At other times, Watson and UK chemistry students have taught young investigators real-life laboratory techniques to purify chemicals and how to design and carry out experiments to test the viscosity of different liquids. Watson and the Explorium hope to expand these activities into week-long summer chemistry camps (the first pilot program was carried out in 2009).

Watson hopes these early hands-on experiences may inspire a new generation of scientists. After missing those experiences as a child, he pursued a BS degree in Polymer Science mostly just for job security. His first hands-on brush with applied science, while doing undergraduate research, then completely changed his motivation. “Keys to a laboratory, access to all those cool toys, and the sudden realization of one’s own creative power to make a difference are just intoxicating,” he said.

For Watson, helping spur the inquisitiveness of young, budding scientists is just one way to repay the years of support he’s received from fantastic mentors during his undergraduate, graduate, and post-doctoral research work—as well as from colleagues at UK.

“I continue to turn to these mentors for advice even today,” Watson said. “I only hope that I can do the same for younger people. My hope is in the next five to ten years we’ll have a larger group of young people in the area wanting to pursue science. Any parent, caretaker, or teacher knows that all children are born highly inquisitive and rapidly begin to conduct experiments to adapt to, understand, and push the limits of their environment. We need more chemists and engineers.”

Like his passion for working with students, Watson’s own research is quite organic.

Inorganic semiconductors, like silicon, are effective but expensive to produce, and the often-high temperature needed to manufacture electronic devices from inorganics adds cost.

These very high temperatures currently prevent their use in a myriad of revolutionary new technologies that are just waiting for the right semiconductors to make them possible: for example, roll up computer screens, cheap portable solar cells, solar energy harvesting paints, and electronic devices constructed from fabrics.

That’s why for decades, researchers have been investigating ways to produce cheaper, plastic (carbon-based) organic semiconductors that could replace the inorganics.

In the last twenty years, they’ve succeeded—to a degree. Organic materials have been developed that could conduct either positive or negative charges, but generally not both.

The challenge was finding a single organic material that could conduct positive and negative charges—rather than just one or the other. 

Recently, Watson’s lab has done just that by developing several successful and distinct varieties of organic polymers—called ambipolar—that are able to transmit both electrons (negative charges) and holes (positive charges).

The Watson group’s work—funded by theNational Science Foundation, the Petroleum Research Fund, and the Kentucky Science and Engineering Foundation—led to a collaborative effort with the research group of Samson Jenekhe, a professor of chemical engineering and chemistry at the University of Washington, who was also working to produce ambipolar materials.

The journal "Advanced Materials" found Watson’s new material and Jenekhe’s research on its high level of performance to be of such importance it was recently featured as a cover story in the publication. Another series of Watson’s polymers are currently under license for use by a private company. By mixing and matching chemical building blocks, Watson’s students are tuning the polymers also to absorb different portions of sun-light for solar cell applications.

Watson’s lab’s main goals now are finding ways to increase the stability of the organic materials they’re developing—and to streamline the chemical processes necessary to create them. Transistors created with most currently available organic materials tend to fail when exposed to oxygen, ozone, or water in the air. So, to function properly, they have to be encapsulated, cutting down on their cost-effectiveness.

“One of our main goals now is to increase the stability of transistors made from these types of materials,” said Watson, who joined UK’s faculty six years ago after serving as a project leader at The Max Planck Institute for Polymer Research in Germany.

Eventually, Watson’s polymers may replace inorganic semiconductors as the go-to building blocks for organic circuits in LED displays, solar cells, transistors, and other electronic applications. In addition to designing new polymers and preparing them by traditional chemical reactions, the Watson group developed a patent-pending method to make them in much simpler ways by eliminating some of the chemical ingredients typically used. This can further decrease environmental impact and cost.