Innovation: Who Made That Super Soaker?

Jens Mortensen for The New York Times

It was a "classic situation" for an inventor, says Lonnie Johnson of the moment in 1989 when he waited nervously for a meeting with toy executives at Larami, a pink Samsonite suitcase on his lap. Inside the suitcase was a new kind of water gun. Instead of a pistol that piddled out a thin stream, this toy was engineered to spray water dozens of feet. "I had bought a milling machine and made all of the parts myself out of PVC pipe and Plexiglas," Johnson says. "Even the valves — I made those too."

Johnson had worked on bigger projects. He was a senior systems engineer on the Galileo mission to Jupiter, based at NASA's Jet Propulsion Lab in Pasadena, Calif. But he still worried about how his invention would go over. As an African-American in a field in which minorities were rare, he was often underestimated, he says. "Most of my career as an engineer, I was put in environments where I was the only person of color in the room."

Johnson knew that the toy industry could be fickle. "It's like the entertainment industry. You can't predict whether a song is going to be a hit and how everyone will react to it." When he finally stepped into the conference room, Johnson didn't say much. Instead, he opened up his suitcase and pulled out a water gun, with a cartoonish plastic bulb mounted on top, that looked like a prop from "Plan 9 From Outer Space."

"Does it work?" Myung Song, the company president, wanted to know. Johnson pumped the gun and pulled the trigger. Water blasted across the room and splatted against the far wall. There was a stunned silence. "Wow," Song said.

"At that point, I knew I had captured their imagination," Johnson says. "They could see what I had seen in the water gun all along." The Super Soaker went on to become one of the top-selling toys of the early '90s.

These days, Johnson has left toys behind to concentrate on solving a more urgent problem: "Energy 'R' Us," he says. With scientists at Tulane and Tuskegee universities, he is working on a method for transforming heat into electricity. He hopes that his technology will revolutionize solar-power panels and make green energy more affordable. "My goal," he says, "is to get this to market as soon as I can."

BESPOKE SOAKER

Ben Trettel has designed his own high-powered water guns. He is working toward a Ph.D. in fluid dynamics at the University of Texas.

How did you get involved in making homemade versions of the Super Soaker? In the early 2000s, Larami found that very large water guns were not profitable. So they started making smaller, less-powerful ones, and that really motivated people like me. We thought, Hey, can we modify these water guns? And, also, can we build our own?

What is the most-powerful water gun you've ever created? I have one called Super Cannon II. The problem with it is the recoil, because it's like you're shooting a rocket. If you're sending many liters of water per second out of a small hole, you're going to have a lot of recoil.

What about the person on the other end? It's got to hurt when you get squirted. A lot of people worry that water streams can cause internal bruising. But I think the recoil is a much bigger issue.

Did your experience with squirt guns inspire you to pursue a graduate degree in physics? Definitely. When I took the undergraduate fluid-mechanics course, I knew a lot of this stuff intuitively. Other students were confused, but I had already experimented with this stuff when I was 15. And because of the water guns, I started reading scientific papers about nozzle design. How do you design a nozzle so that a stream of water shoots farther? This is a question at the cutting edge of science. And yet a teenager can work on this problem himself, do some experiments and actually make some progress with it. And that's kind of cool.