A life lived inventing: Local scientist inducted into Inventors Hall of Fame
It’s possible that if you bought a phone, laptop, television or diapers in the past 20 years, Dr. Dennis Krueger had an influence on those products.
Krueger, a longtime Hudson resident who now lives in River Falls, was inducted into the Minnesota Inventors Hall of Fame in December. He had an illustrious career as a scientist with 70 patents to his name.
Shortly after receiving his doctorate in material engineering from the University of Michigan, Krueger moved from Ann Arbor to Hudson to work for 3M. Krueger’s reason for not moving to St. Paul, where 3M headquarters are located, is simple.
“I was born in Wisconsin, I wanted to stay in Wisconsin,” Krueger said.
Born in Merrill, Krueger began working for 3M in 1972, a career that would span almost three decades, retiring in 2001.
Going to work for 3M as a corporate scientist was an easy choice, according to Krueger, with a diverse company and having an opportunity to research anything he was interested in.
“I could do anything I wanted to,” Krueger said. “There was always some technology that would be of interest to me.”
Krueger said almost all of his patents came from his work at 3M, except for one that came from his work at DOW chemical.
By his colleagues at 3M, Krueger was known as the “Father of Coextrusion,” but Krueger said his introduction to coextrusion was during his time at DOW Chemical, where he worked alongside Walt Shrink, who invented coextrusion.
Coextrusion is the process of extruding two or more compatible metals or plastics through the same dye. These films can have hundreds of thousands of layers to them.
In Krueger’s opinion, a series of patents that weren’t even in a product were some of his work he’s most proud of.
“It has to do with, I think it’s a new discovery in science, using electric fields to cause a polymer film to crystallize in a desired structure...so it can sense heat or be used as a speaker,” Krueger said. “But it never ended up, it started to go into telephone keypads, the touch keypads, but the division didn’t follow through on that. To me, that was really some good science.”
However, Krueger’s patent related to a crystallized liquid film inside the displays of phones, IPad’s, laptops, and televisions have helped with display functions like increasing battery life.
Krueger said he isn’t sure about how much of his inventions are still used in 3M technology but said one of his greatest inventions during his tenure was with elastic in a diaper.
“That elastic film was one of my greatest inventions, as far as novelty,” Krueger said. “It’s elastic like a rubber, but not tacky like a rubber…This is silky smooth.”
Krueger said he remembers the night he and his colleagues finally created the elastic film. Krueger called it a “eureka moment”.
Doug Cornelius, board member at the Minnesota Inventors Hall of Fame, said there were about a dozen different nominations each year. Selecting Krueger for the distinguished award was based on the long career that Krueger had and the “breadth of his contributions.”
Along with the patents, individual awards, and hall of fame, Krueger said he’s proud of his Carlton Society award given to him by 3M. The Carlton Society is the highest honor a person at 3M can receive, an award reserved for 3M scientists who innovate new products.
Since retiring from 3M and moving to River Falls, Krueger still has a connection to Hudson. Krueger has owned a woodshop there where he and his friends spend hours creating different woodworking projects for the past dozen years.
When you walk into his woodshop office, on the walls are groupings of plaques commemorating the various patents from Krueger and 3M — a reminder of the success he’s had over a long, inventive career.
When he’s not in his woodshop, Krueger enjoys traveling and photography. Krueger recently took a voyage to Australia and New Zealand where he took around 6,000 photos.
It’s been 16 years since he worked at 3M in the corporate research division. When he reflects back on that time, Krueger remembers it fondly.
Krueger said his best advice to young, upstart scientists is to seek a mentor — something he did during his tenure.
“I always had students who I would mentor that gives them a background,” he said. “That’s what I would recommend to budding scientists. To go seek out a company and work with some researchers.”