Manufacturing energy

Lindsay Miller (Ph.D.’12 ME) remembers the first time her career ambitions came into focus. “I was getting very near to deciding whether to apply to grad school or take a job,” she says. “I was reading a National Geographic article on wind energy, and it really resonated with me. I realized I could pursue my engineering interests while having a broader impact in areas that I care about. That’s what got me on the track of alternative energy.”

Lindsay Miller (Courtesy of Lindsay Miller)Lindsay Miller (Photo by Lindsay Miller)Her interest in how systems function—both in the natural world and the human-built environment—led Miller to study mechanical engineering at Case Western Reserve University in Cleveland. During that time she interned at Procter & Gamble and then at the NASA Glenn Research Center. “I enjoyed both experiences,” she says, “but neither one was what I was looking for as a career.” So she started researching graduate schools.

Miller decided on Berkeley for her master’s and then doctorate degree because of the university’s reputation for groundbreaking alternative energy research and its multidisciplinary approach. She applied for a position in the lab of Paul Wright, ME professor and CITRIS director. Wright’s lab is part of the Berkeley Manufacturing Institute, which brings together engineers from EECS, ME and MSE to develop new products to make modern manufacturing more energy-efficient.

While a Ph.D. candidate, Miller investigated techniques using microelectromechanical systems (MEMS) to harvest wasted energy at residential, commercial and industrial scales during ambient vibration from common sources like motors, fans, pumps and pipes. Miller wanted to reuse the salvaged energy to power the wireless sensors that are becoming increasingly common.

“My research was trying to make wireless sensor nodes that never die—batteries that can be recharged infinitely by energy available in the environment,” says Miller. “That becomes relevant when we start talking about smart grids, smart buildings and the Internet of Things—or any application where monitoring temperature, occupancy, flow-rates or pressures will help operate things in an intelligent way.”

Miller’s microelectromechanical energy harvesters. (Courtesy Journal of Micromechanics and Microengineering, vol. 21, 2011)Miller’s microelectromechanical energy harvesters. (Photos by Journal of Micromechanics and Microengineering, vol. 21, 2011)As a post-doc in Wright’s lab, Miller became intrigued by the process of turning a prototype into a device ready for real-world application. So she teamed up with MBA students at the Haas School of Business in a program for prospective entrepreneurs called “Cleantech to Market.”

“In the lab we would throw around ideas about how this might turn into a commercial product someday,” Miller says. “But the Cleantech-to-Market team really dug down to see how that would happen.”

Miller says she might pursue her research as a business venture in the future, but right now she is focusing on her new position with Alphabet Energy, a Hayward, California-based company co-founded in 2009 by Berkeley MSE and chemistry professor Peidong Yang and alumnus Matthew Scullin (Ph.D.’09 MSE). The company is developing thermoelectric devices that will capture and convert waste heat energy into electricity. The devices can be attached to flue or vent pipes at factories to save some of the energy that is created and lost during manufacturing processes. The same devices could also be attached to car tailpipes.

Alphabet’s thermoelectrical devices are made from silicon semiconductors, making them modular and inexpensive to build and deploy. Miller works with a team to figure out how to scale the technology from the lab bench to large installations.

After years of study and preparation, Miller can see how her work at Alphabet Energy connects back to the inspiration she had about alternative energy as an undergraduate. “I think the technology has huge promise and potential impact,” she says.