Young inventors from around the country gathered in D.C. on April 22 for the fourth annual White House Science Fair, seriously impressing the president with their projects and ideas for the future.

About 100 students from 40 states, ranging in age from 8 to 19, were invited to set up their projects in all corners of the White House — from the South Lawn to the State Dining Room. Students displayed projects ranging from portable windmills to oil-producing algae, underwater robots and dehydration-preventing football gear. The cohort of kids included app-coders, rocket-builders, video-game designers, and city planners. And as the president pointed out, many of them were not yet old enough to drive. One team of innovators even helped the president hop onto a bike to test out their pedal-powered water filtration system. Check it out in the video below:

Other notable inventions included:

  • Low-cost, 3-D printed prosthetics: 17-year-old Easton LaChappelle has created a mind-controlled prosthetic arm for the low price of $250, using parts cheaply replicated from a 3-D printer.
  • Tactile sound device: Eighth-grader Jonah Kohn developed a tactile-sound device to help the hearing-impaired enjoy music.
  • Better pancreatic cancer test: 16-year-old Jack Andraka developed a dipstick paper sensor test for pancreatic cancer that is faster, cheaper and more sensitive than current pancreatic cancer tests.
  • Hydrating athletic gear: A team of second-, third- and fourth-graders from Georgia dreamed up a system to automatically cool down and hydrate sweating athletes.
You can watch a video of Obama touring all of the projects at this year's White House Science Fair here:

After touring exhibits, Obama congratulated the students on their amazing projects and announced new plans to support research and innovation in STEM or Science, Technology, Engineering, and Math fields. 

Related on MNN: 20 of the most impressive science fair experiments of all time

White House Science Fair astonishes Obama
Young scientists from across the nation amaze President Obama with their inventions at this year's White House Science Fair.