A few years ago, Tom Dickinson lifted the lid from his grande americano and started wondering about the water droplets that clung to its underside. Why were they that size? Why did some merge into bigger drops surrounded by little drops?
Coming from someone else, such questions might indicate that the asker has too much time on his hands. Coming from Dickinson, they launch serious research-and new careers.
Dickinson has an international reputation in the physics of surfaces and optics, and a lab that every summer brims with undergraduates doing research projects. In fact, his resume wouldn’t show nearly the breadth it does without his young collaborators. He says undergrads have let him branch out into new lines of inquiry, because they bring an exhilarating fearlessness to laboratory work.
“I can take a fairly nontraditional idea and try it, because undergraduates aren’t afraid of anything,” he says.
An idea like how water droplets behave. He enlisted undergrad Ryan Leach ’04 to film the formation of drops on a clear plastic sheet and develop a mathematical model to describe their growth and movements. Leach ended up showing that droplets can be used to mix minute quantities of chemicals, allowing the production of specks or nanoparticles that have biomedical applications such as delivering tiny doses of a drug to a particular site in the body.
Dickinson explains that scientists run two main risks with any new experiment: first, whether it will work at all; and second, if it does work, whether the results will be meaningful and valuable. On the other hand, he says, “if you don’t take risks, you won’t make breakthroughs.”
That poses a problem for graduate students; since they need to get publishable results to progress in their careers, they tend to choose—and their advisers encourage them to choose—projects that are likely to succeed. In other words, projects that are safe.
It’s different with undergraduates.
“They have no fear of failure, because it’s all exciting to them,” says Dickinson. “We can try new things, even though they’re risky. And these kids are willing to do it.”
The risky ideas his students pursue usually emerge from Dickinson’s own quirky curiosity about things most of us don’t think twice about, like the droplets on his coffee lid, or how breaking a Wint-O-Green Lifesaver generates sparks of light.
Several of his undergraduates have worked on triboelectricity. “Tribo” refers to friction, and “triboelectricity” is the charge that is generated when two surfaces touch or rub against each other. It’s what gives you a shock when you get out of your car or touch a light switch after walking across certain kinds of flooring. In the lab, Dickinson and his crew move a tiny electrical probe along a surface and measure the charge separation that develops.
“It’s a function of how hard you push, how fast you move, and the materials,” he says. Understanding triboelectricity is crucial in the production of ever-tinier electronic components, where even small discharges can severely damage the product.
The friction that creates triboelectricity isn’t always damaging; it also can be harnessed as a lithographic or etching tool. Former student Ann McEvoy ’05 used it to create a minute trench in a mica surface. It was an early step in creating a tiny holding pen for strands of DNA prior to their use in an experiment.
Despite working on relatively risky projects, more than half of Dickinson’s undergraduate collaborators end up publishing their work with him in scientific journals. That’s a huge advantage when the students seek admission to graduate schools. McEvoy is now working toward a Ph.D. in biophysics at the University of California-Berkeley. Leach is studying meteorology—probably the pinnacle of droplet research—at the Navy Post-graduate School in Monterey, California.
Dickinson says he pushes his student researchers hard to take their research as far as they can.
“One of the functions that I think we perform here is getting them to realize what they have to do to write a publishable research paper,” he says. “It’s different than a report submitted to a teacher. It’s really a couple of notches harder.”
Other benefits of the experience are subtler. The students get to know firsthand how a first-rate scientist thinks.
“Often you’ll start with one thing, and it goes off in another direction,” Dickinson says. “That’s something that I think is good for them to see.”
One of Dickinson’s favorite moments is when students come to him with a result they didn’t expect and don’t understand.
“They’ll see something and know that it’s new, but they don’t know what to do next,” he says. When that happens, Dickinson starts with the questions: Can it be explained? Is it valuable? What do we do with it?
When they’re able to see on their own what to do next—”That’s a big step,” he says.
With the hindsight of someone who’s come through the program and is now embarked on her own career, McEvoy sums up her experience. Amid the brainstorming and troubleshooting, she says, what Dickinson taught her was “what it means to ‘do science.'”