In a darkened work area just off the museum's main exhibit halls, Minerva got her first close encounter with a crowd of skeptics. At first, the youngsters weren't quite sure what to think of the odd, whirring creature with ever-moving "eyeballs" -- twin cameras -- perched atop its boxy body. Then, Minerva's "face" broke into a recognizable grin, and the pre-schoolers swarmed around the little graduate student.

They squealed in delight as Minerva's female voice exclaimed, "It tickles" when their little fingers brushed against her row of sensors. When they got too close, though, the voice chirped "Fire!" and the youngsters scattered.

Sebastian Thrun, the robot's lead inventor, said Minerva is designed to interact with people. "When people come close, it's happy. When people stay away, it's sad," he told the preschoolers.

Minerva, named for the Roman goddess of wisdom, is one of the world's first robotic museum tour guides. Officials at the Smithsonian's National Museum of American History hope she will be as popular with adults as she was during last week's sneak preview with the youngsters.

Today through Sept. 5, Minerva will be hosting visitors to the museum's "Material World" exhibit. The robot will help explain how objects made of wood, metal and plastics have influenced our lives.

Art Molella, director of the museum's Lemelson Center for the Study of Invention and Innovation, said that while Minerva is sure to be the center of attention, "the young engineers are on display, more than anything else."

Mr. Thrun, 31, is an assistant professor at Carnegie Mellon University's school of computer science. His robotics team is made up of staff members and graduate students from the Pittsburgh university.

"Our goal is to highlight the inventor as a career and a way of life," Mr. Molella said. "Our visiting public is not well-acquainted with the lives of inventors, so we're eager to put them before the public.

Mr. Molella said he was most intrigued by how the engineers "taught" Minerva.

"It's interesting to see those young guys tap away on their laptops to bring this creature to life:' he said. "Minerva's a quick learner. She's got a very fast learning curve."

Nevertheless, the team put in some marathon sessions last week at the seven computers needed to operate Minerva. Sophisticated computer programs are needed for even the simplest tasks, such as curling the "mouth" into a smile or a frown.

"People aren't impressed by the technical details, like navigation systems. They've seen that on science fiction:' Mr. Thrun said. "They're more interested in the face, and the ability to interact with humans."

In fact, Minerva's mouth and eyebrows -- a red headband and two blue cloth bands -- are a recent addition. One of Mr. Thrun's graduate students suggested it as a way to make the robot seem more approachable to humans.

Minerva has made several excursions around the museum's exhibit hall as a camera captured images of the ceiling overhead. About 500 of those images were then pieced together like a "mosaic" to form a computerized map for Minerva.

Minerva's cameras will use the ceiling lights like stars to navigate through the exhibit. The robot also uses sonar and a web of infrared laser beams to sense objects in its path to avoid running into walls or visitors.

Mr. Thrun said Minerva's ability to learn from its surroundings, along with its sophisticated "collision avoidance" system, are what sets it apart from other robots.

"But we do more than just avoid people:' Mr. Thrun said. "The interactive systems allow it to look for people and smile at them."

Beyond simply entertaining visitors, Mr. Thrun and his team plan to run different scientific experiments every day." Students can run new software, test new theories, gain new insights into navigation and interaction," he said.

 
For example, they will try out software to help Minerva learn new social skills, by measuring how close people come to the robot, or how long it takes for them to touch its interactive screen.

Eventually, Mr. Thrun thinks, robotics could spark a revolution in health care. For example, robots could someday help doctors monitor older patients in their homes, using the robot's cameras and display screens to watch for signs of trouble in their facial tones or speech patterns.

For now, though, Mr. Thrun will be content if Minerva survives the two-week stint at the Smithsonian.

"But the real success will be if people love it:' he said. "I think they will."