You may recognize Erik Christensen, 51, a Seattle bus driver for 12 years, as he drives the Metro Route 57 that heads from downtown stopping along Admiral Way around 3:00 p.m. (He also drives the 15, and 7 express.)

You might have even heard Christensen play his own compositions on his acoustic 12-string guitar. He will perform on Feb. 11 at C&P Coffee on California Ave. 6pm to 8pm. His Influences include John Denver, Frank Zappa, Motown, and Mozart.

He said he admires Hank Williams, Sr., "because he plays from the heart", which is where Christensen plays, even when he plays with robots. But he does more than play with the hundreds he has built, he teaches kids to build them, too, and to put their hearts into what he described as "more than just a hobby" for him. He uses LEGO components and his laptop computer.

He will offer a class in robotics at Youngstown Cultural Arts Center on Delridge beginning Feb. 20. Classes run Mondays and Fridays from 3:45pm to 5:15pm and continuing until the end of the school year. The cost is $60 per month. To sign up, email him at legobots@hotmail.com.

"Robots are essentially dumb," said Christensen. "They don't know anything. We tell them everything they need to know. How far to go. How fast. For as little as less than $300 you'll have an educational kit that will give kids years of entertainment and learning. You can even build a LEGO robot that will hold and solve a Rubik's cube in 10 seconds.

"I taught several years as a volunteer at Gatewood Elementary School," he said. "About eight years ago a friend invited me to spend an hour a week with a student who was having some troubles. That turned into two hours a week which turned into every day. The next year a teacher invited me to be in the classroom with him, tutoring in all subjects. The third year I struck out on my own and used electronics to get kids interested in math.

"I enjoyed getting through to the kids," he said. "They just have to get past that fear that it's a great big number. No it's not. It's a bunch of little numbers. I wasn't challenged as a kid in school. Robotics really challenges the kids, gets their brains rolling. The more kids get interested in tech now, the better prepared they will be in college to build machines to make a difference."

He emphasized that electronics is not just a boy's club.

"Not enough girls are involved in science these days," he said. "Some of the scientific breakthroughs going on right now, it's women. God bless them for that. Come on girls, come join my class," he enthused.

At Youngstown, in addition to building robots, his class will learn about the "six simple machines", the wheel & axle, lever, screw, wedge, pulley and inclined plane.

"Mechanical engineering goes back to 250 B.C. when some of the first robots were invented," Christensen pointed out. "The sliding door, coin operated machine, steam power, hydraulic pump date way back. What you're doing is nothing new, you're just doing it in a different way."

During the summer, UW employs Christensen to set up their summer youth program robotics course for middle school students.

"We get to stick our noses in all these labs and meet cool professors," he said. "Last year they met this professor who measured the density and speed of rain drops. His lab had a density tunnel and lasers. This can help improve predicting weather."

He teaches the summer course with Paul Kulchenko, who designs advanced robotic devices, including an electronic arm that holds a ping pong paddle horizontally, bouncing two ping pong balls. The paddle's position adjusts to keep the balls bouncing, tracking them with high-speed cameras. You can view a demonstration here.

"I like to go for the most playful side of technology," Christensen said. "The military's doing just fine without me. I know some of the kids interested in this will get snatched up by the military. I promote what's called 'gracious sumo robots', where kids compete and their robots push each others' out of the ring. I'll say, 'Yes, you just kicked that little kid's butt. Now go over and sit down with him and show him how you did it so that he too can get up to your level."