Miles Barr: Printing Solar Cells on Paper and Clothes

Drawing the Curtains to Let in the Sun
Photograph by Corey Hendrickson for Bloomberg Businessweek

Forget about putting solar panels on the roof. Miles Barr wants to make curtains, cell-phone cases, and even shirtsleeves that generate electricity from the sun.

Barr, who earned a chemical engineering Ph.D. at Massachusetts Institute of Technology, is an expert in chemical vapor deposition. That’s a process in which two vapors are piped into a sealed chamber, where they react, creating a thin, solid film around an object inside. The technique isn’t new; it’s been used to add a waterproof layer to fabric, for example. Barr successfully adapted the technology to “print” an electrically active solar cell coating onto ordinary materials, starting with a sheet of paper in 2010. “When we first did that, it really sparked a lot of imagination,” says Barr, 28. “If you can put a solar cell on paper, what else can you put it on?”

Chemical vapor deposition changes the quality of a surface without using extreme temperatures or solvents that might cause damage. When Barr’s team at MIT figured out how to use the process to make solar cells, he says, they went to an office supply store and loaded up on stuff to test it on: “Saran Wrap, copy paper, tissue paper, almost anything you can imagine,” he says. Barr maintains the technique could be adapted for mass production. Because it relies on abundant organic molecules, rather than heavy metals or rare elements, it could be cheap, too. Right now, Barr’s solar cells convert only about 2 percent of the energy in light into electric power, compared with 10 percent to 20 percent for conventional photovoltaic panels, though he thinks he can eventually raise the efficiency to 10 percent.

As a high school student in Kansas City, Mo., Barr built a walking robot monkey for a science project, using a salvaged windshield wiper motor to power the monkey’s steps. At Vanderbilt University as an undergraduate, he majored in chemistry, math—and music. He still plays trombone and piano. Music and engineering share some common threads, he says: “You’re combining individual elements—different instruments, different harmonies, different melodies—to make something better.”

Last year, Barr co-founded Ubiquitous Energy to embed solar technology into everyday objects such as windows or cell phones, which could be particularly suited to people living off the grid. The Cambridge (Mass.) startup is doing “something very different from what other people are working on in solar,” says Arunas Chesonis, chief executive of the biofuel company Sweetwater Energy, who led a $1 million angel investment in Barr’s company. “It has a real opportunity to help not just the developed world but the developing world,” he says, by letting people in remote villages, for instance, easily charge cell phones with the sun.

The cost of installing panels keeps many people from adopting solar power, Barr says. By integrating it into ordinary materials, he thinks he can clear that hurdle. “You’re already hanging a curtain in your house,” he says. “Why not add some energy to that?”