DOWNERS GROVE, Ill. (WLS) -- He is a 97-year-old jewish immigrant scientist who escaped Nazi Germany.
He did vital work for the Manhattan Project helping to create the atomic bomb, and now he's working on a clean energy solution to climate change.
ABC 7 spoke with Dr. Dieter Gruen at his home in west suburban Downers Grove about his life and legacy.
"My life has been spent doing scientific research in the energy area," Dr. Gruen said.
After living through the rise of the Nazi Party and Adolf Hitler in German, Dr. Dieter Gruen came to the the United States, Little Rock, Arkansas, in fact, to live with family.
In Germany, "my classmates after school would beat me up because I was jewish. So I couldn't go to school any longer," Gruen said.
Both of his parents were sent to concentration camps.
"My parents were very very fortunate," Gruen said. "In those days they were not yet killing jews. They let them go if they could leave Germany in 24 hours."
The family reunited in Chicago several years later.
Gruen received his bachelor's in Chemistry from Northwestern University and went on to graduate work at the University of Chicago. He graduated cum laude in the summer of 1944.
"It was then that I was recruited to work on the Manhattan Project," he said.
Gruen did his work in secret in Oak Ridge, Tennessee.
"We separated 60 killograms of Uranium 235 which was shipped to Los Alamos in New Mexico to be fashioned into the bomb...to be dropped on Hiroshima," Gruen said. "After the war ended, many of us felt that should never happen again.
"It's one of the problems that we face that we have to solve. We must not allow nuclear weapons ever to be used again," Gruen said.
Even now, in his retirement, he is working as a scientist on what he describes as an existential problem: climate change.
"Many people feel that maybe beyond the age of twenty five or whatever you don't have any new ideas," Gruen said. "I have found in my life that is not the case, that creativity and new ideas persist throughout one's entire life."
Gruen is working to develop a highly efficient solar cell to convert light into electricity.
"There is no 'Planet B,'" Gruen said. "This is our home. Here, right here on Earth. The sun could become our global energy source...and we have to learn how to use it efficiently.
"I count every day I'm able to do this," Gruen siad. "I won't last forever but I'll do it as long as I can."
Dr. Gruen today is working on a new high efficiency solar cell that he hopes can revolutionize the future of solar power.