From atomic bomb to solar power, Downers Grove scientist always innovates

By Burt Constable

Dieter Gruen escaped Nazi Germany, worked on the Manhattan Project during World War II, helped design nuclear submarines, earned patents throughout a celebrated and innovative career at Argonne Laboratory, and is still working on a more efficient form of solar energy at age 98.

That’s why U.S. Rep. Sean Casten is nominating his fellow Downers Grove resident for the Presidential Medal of Freedom.

“Dr. Gruen is a renowned scientist and fierce advocate for climate action whose contributions over eight decades have transformed American technological development, from nuclear fission and fusion to solar and energy storage. We as a nation are forever in his debt,” says Casten, a Democrat who drafted a letter to President Joe Biden with fellow Reps. Bill Foster, a Naperville Democrat; Arkansan Republican French Hill; Cheri Bustos, a Democrat from East Moline; and California Democrat Jerry McNerney.

Gruen came to the United States from Germany in 1937 as a 14-year-old.

“I left for the reason I could no longer go to school. It was very difficult because of my religion,” Gruen says, explaining how his Judaism made him a target in his hometown of Meiningen in 1930s Germany. “I could go, but they would beat me up after school, the Hitlerjugend or Hitler Youth.”

His father, Joseph, a principal at a school, and his mother, Meta, arranged for him to live with relatives in the United States.

“At that time it was possible to leave Germany if you had a visa,” Gruen says. He sailed to New York on the White Star Line’s HMS Georgic with his brother, Herbert, who was eight years older and had been going to school in England. He lived with an uncle and aunt in Little Rock, Arkansas, where he was part of a sizable Jewish community. He learned to speak English fluently without an accent and excelled in school.

He graduated from Little Rock Central High School, which later became the civil rights epicenter of the Brown v. Board of Education Supreme Court decision that integrated schools.



“I took chemistry in high school in Little Rock and that’s where I really became interested,” Gruen says.

In 1939, his parents were sent to a Nazi concentration camp in Buchenwald, where they were given 24 hours to leave the country and managed to make it to relatives in Luxembourg “about six months before the war began,” Gruen says. He reunited with them after they came to Chicago. Gruen would take the “L” from their apartment in the Uptown neighborhood to Evanston to attend classes at Northwestern University.

“I used to have lunch on the shore,” Gruen remembers. “There were rocks there, and I’d eat the sandwich my mother had prepared for me and dangle my feet in the water.”

Excelling in his major of chemistry, Gruen was selected to serve his nation. “I was recruited to work on the Manhattan Project, so I went to Oak Ridge, Tennessee, and worked there until April of 1946,” he says. Uranium largely consists of two isotopes, U-235 and U-238, and Gruen created a new material that enabled scientists to extract the U-235 used to make the nuclear bomb that was dropped on Hiroshima.

“After the bomb was dropped, quite a few of the people got together and recognized this should not happen again,” says Gruen, who helped form the Oak Ridge Scientists and Engineers group determined “to prevent another nuclear device being used again.” Their work led to the Atomic Energy Act of 1946, which regulated how the new nuclear energy would be used.



After the war, Gruen got his doctoral degree in chemical physics from the University of Chicago, where he worked on the magnetic properties of the newly synthesized element neptunium and helped determine its place in the periodic table.

He was hired by Argonne National Laboratory in 1947 and developed a method of “protecting the uranium fuel from corrosion” in nuclear submarines.

Working in a lab at the Foote Mineral Co., Gruen earned a patent in 1949 for his method of using distillation to separate the elements of zirconium and hafnium, which is used in control rods of nuclear submarines. Gruen experimented with elements essential to nuclear reactors and then cardiac pacemakers, and his work with transuranic elements led to the category 5F in the Periodic Table.

“He’s been able to move from one field to another,” says Larry A. Curtiss, an Argonne distinguished fellow and senior group leader who did research and collaborated with Gruen during their careers. Gruen’s inventions have made nuclear power safer, improved medical devices and advanced alternative energy solutions. Gruen has never slowed down.

“He discovered (a nanocrystalline diamond film used in biomedical applications) at 70, when most people have retired,” Curtiss says.

At Argonne, Gruen has served as senior scientist and group leader, as well as associate director of the Materials Science Division. He was named an Argonne distinguished fellow, emeritus, in 2012.

He currently is working on designing more efficient solar energy panels using graphene, a structurally different form of carbon.

“I have a prototype. What I need are investors,” says Gruen, who went to Boston last week to discuss his research. He did much of that research at the University of Illinois in Chicago.

“The sunlight is pure energy,” Gruen says. “We get enough energy in sunlight in one hour for the energy needs of all 7 billion people for a year.”

Reps. Casten and Foster share a science background with Gruen and have become friends.

“I’ve spent several afternoons in his backyard,” Casten says of Gruen. They talk about solar power, climate change and new forms of energy.

Gruen met his wife, Dolores, while they were graduate students at the University of Chicago. “We had a very happy and fulfilling marriage,” says Gruen, who was married 66 years when his wife died in 2015. She was a pioneering school psychologist and psychotherapist. They had two daughters — Erica, an Emmy-winning producer who became president/CEO of The Food Network, and Karen, who is a psychologist and consultant — and a son, Jeffery, a physician who founded an innovative health care company.

“I feel very, very honored,” Gruen says of his nomination to receive a Presidential Medal of Freedom. Casten nominated him last year and took Gruen as his guest to the State of the Union in February 2020, when there was a medal presentation made to Rush Limbaugh.

“I was just a few feet away when he received the medal,” Gruen says of the ceremony when first lady Melania Trump hung the Presidential Medal of Freedom around the neck of the radio personality. “I really don’t expect to get it this time, but it’s nice to be nominated.”

Casten says Gruen’s accomplishments merit the award, but his story as an immigrant who persevered is equally inspiring.

“He is just so filled with hope,” Casten says, noting Gruen never gave up hope when he was getting beaten up by Hitler Youth, when his parents were in a concentration camp, or when nuclear war and now climate change threaten our planet. “He didn’t lose faith. It’s the American spirit at its best.”