WASHINGTON (AP) -- President Barack Obama is holding his third science fair to highlight projects by student winners of science, technology, engineering and math competitions from around the country.
The White House says Monday's event is part of the president's effort to inspire more girls and boys to excel in so-called STEM subjects.
About 30 student teams were invited to show their projects. Rockets and robots are among the exhibits, as well as a fully functioning prosthetic arm made mostly with parts generated using a 3-D printer.
There's also a collapsible, transportable, bicycle-powered emergency water-sanitation station that filters E. coli and other harmful pathogens from contaminated water.
At the fair, Obama was expected to announce new steps to encourage more students to study and excel at science, technology, engineering and math.