Baltimore (CNN) - Lenny Robinson is still getting acclimated to his 15 minutes of fame. When he pulled up to Baltimore's Sinai Hospital in a black Lamborghini decked out head to toe in a custom Batman outfit, he was greeted by a crush of reporters, news photographers and giddy hospital staff armed with smartphones snapping pictures.

Robinson became a viral video sensation last month when police pulled him over in full costume.  The dashboard camera in the Montgomery County, Maryland, police cruiser caught the entire scene, including the officer calling for back up. “You can send me Robin if you wish,” the officer snickered to dispatch before asking the driver, “What’s your name other than Batman?”

“Lenny,” Robinson replied from the driver’s seat in a cape and Batman headdress.

The police pulled over Robinson’s car because instead of a Maryland license plate, he had the Batman logo. He likes his outfit and car to look just right when he visits hospitals across Washington and Maryland to cheer up terminally ill children. Once police heard that and saw that the official license plate was inside the car, Robinson was on his way both to the hospital and Internet stardom. Last week a local paper unmasked the caped crusader with a front-page article detailing the charitable work done by the 48-year-old father of three.

Parked outside Sinai in a valet lot where expectant mothers come at delivery time, the Robinson Batmobile gleams. The black Lamborghini is customized with yellow trim and tricked out with the Batman logo nearly everywhere, including on the floor mats, the door jams and the monster rims. A collection of "Batman" themes blasts out from the stereo. Robinson grins from ear to pointy ear, fielding interviews and breaking away to pick up a sick child, say hello and cheer them up.

Upstairs, Hope for Henry is having its annual superhero celebration.

“We’re delighted to work with him and bring the magic of Batman to these kids,” says Laurie Strongin, executive director of Hope for Henry. Her group has brought pizza, cupcakes, superhero capes and games to help young cancer patients with their treatment by making them forget, for one afternoon, that they’re stuck in the hospital.

Strongin knows firsthand what the families here are going through. “My husband and I started Hope for Henry back in 2003 to honor the life of our son Henry, who had died when he was 7 years old after a bone marrow transplant,” she says.

Henry was a Batman fanatic. He never got to meet Robinson, but Strongin says Henry would have loved the day.

When Batman walks into the room, all the heads in the room turn. Sick children have a glimmer in their eye. Robinson flashes a smile and grumbles, “I’m Batman.”

And for the next two hours he is as close to the real thing as possible.

“I know the suit weighs almost 40 pounds and I lose approximately between 5 and 6 pounds of water weight each time I do it,” he says after autographing a boy’s forearm just above the tiny hospital bracelet.

“The car was a quarter-million dollars and the suit was 5 grand, and I give away approximately $25,000 worth of Batman sunglasses and T-shirts and hats (and) coloring books, and everything I give away I always sign. But it wasn’t about the money. It wasn’t about spending the money on the car or the suit. It was about coming to see the kids,” Robinson says.

While the party also features a man dressed as Spider-Man and a woman dressed as Wonder Woman, Batman is the star. He’s giving out books and toys, and if you’re under the age of 14, you’re starting wonder whether this actually may be the real Batman.

“Some of these kids recognize that this is not Batman, but in their head it is, and this is a great thing for them,” says Dr. Joseph M. Wiley, the hospital’s pediatrics chairman.

The party is medically important for the patients, Wiley says. “It is absolutely clear to those of us in the field that attitude and play therapy and distraction help children overcome illnesses, so this is a big deal for all the kids who are here today.”

Robinson says, “It’s rewarding in a whole different way, just making that child smile. And if I only just touch one kid out of all this, then I know I’ve done something really successful.”

Robinson volunteers much of his time these days as Batman at events such as this one. In 2007, he sold the industrial cleaning business that he began in high school. He told The Washington Post that his volunteering is part of his own maturation process, nodding to a few brushes with the law in his younger years thanks to, according to the Post, “fights and other confrontations.”

He says his cleaning business - which cleaned office buildings, churches and synagogues - was fulfilling, but being Batman and cheering up sick children is his calling.

“You see what’s going on. It has to be moving. Sometimes you’re crying on the inside but you’re strong on the outside. These are the real superheroes. It’s not me, it’s not you. They’re fighting for their lives every single day,” he says.

Robinson says he hopes to take his act on the road and around the world. Turns out that getting pulled over by police was one of the best things ever to happen to Batman.

Before we leave, he stops and looks right into CNN’s camera. He says he has been working on his closing line.

“Remember, at the end of the day, ask yourself, ‘Self, did I make a difference?’ And the answer had better be yes.”