During many years of home experiments, Kehoe blew bubbles that bounced like superballs in his bathtub — but he couldn't re-create those because in his excitement he hadn't taken notes. He invented glow-in-the-dark bubbles that lit up a room. And early on, the non-chemist even used a caustic chemical to accidentally make bubbles that ate holes through clothes.

Kehoe invented many other toys, too, including his floating "Aqua Radio" that can be heard underwater. In recent years, the father of five wrote his acclaimed "Vincent Shadow" children's book series, as well as "Furious Jones and the Assassin's Secret," which will be released April 8. He also helped found "Charity Aware," a nonprofit youth philanthropy.

"Tim had a brilliant mind and was always larger than life," said his wife of 19 years, Sherri Kehoe. "He truly had a passion for creating and inventing. He was an amazing husband and father, who taught the kids to never, ever give up no matter what, and that there is always more than one right answer. He also made sure the kids knew to always follow their hearts and their passions so that they could live happy, fulfilled lives."

Kehoe was a rising star when he won Popular Science magazine's 2005 Grand Prize for General Innovation and was among Reader's Digest's "America's Hundred Best" in 2006 for his vanishing-color bubbles.

Kehoe's boiling and toiling for a bubble that wouldn't stain took him from mixing Jell-O and food coloring with soap bubbles to hiring a renowned chemist after receiving $500,000 in financial backing.

"I was always ruining things, starting fires and explosions and having to evacuate the kids," Kehoe told the Star Tribune in 2006.

After eight years of work, his first big breakthrough came in his kitchen when he blew perfect blue bubbles.

They turned kids and clothes blue, yet the color washed off. Still, big toymakers and mothers whose kids tested the products said they wanted the color to vanish.

"It had to fade away; mothers didn't want to be scrubbing," Kehoe later said.

After another breakthrough by his dye chemist, Ram Sabnis, Kehoe produced colored bubbles with dye that faded away when exposed to water, pressure or air. They applied for a patent in 2005.

Mike Haney, a former Popular Science executive editor, wrote about Kehoe's quest to invent disappearing bubbles.

"What I loved most about the bubble story wasn't just that he worked on it for 11 years, but that he wasn't just an obsessive genius or crank," Haney said. "In that 11 years, he raised kids, bought a house, got real jobs, learned new skills. So even when it seemed like he had abandoned his dream, he hadn't — it was just on hiatus while he did the practical work of living. That was what always inspired me, and I think drove such interest in that story when we published it, because it was something everybody could relate to. Being a little Tim Kehoe seemed possible for anyone."

In April 2011, Crayola LLC sued to block the patent awarded to Kehoe and C2C Technologies, a Minnesota-based company, claiming that colored bubbles should be in the public domain.

Production and sales of Zubbles shut down as Kehoe struggled to find a way forward for his invention.

"His death is immensely sad," Haney said, "not just for the terrible loss for his family, but for the rest of the world, who will miss out on another 40 to 50 years of Tim being Tim, who just couldn't help but make the world a better place."

In addition to Sherri, Kehoe is survived by children Alexandra, Isabella, Seamus, Liam and Gabriella; parents Marilyn Lais Kehoe Olson and Thomas Kehoe and stepfather Richard Olson; and brother Patrick Kehoe.

Services have been held.

Joy Powell • 612-673-7750