One invention that can make the world a better place. That is the theme of Doodle 4 Google 2014 announced by the search engine giant.

Google encourages young artists to imagine an invention that can make life easier for everyone. The contest is open to K-12 students of schools in the United States. Doodles must be submitted on or before March 20.

"At Google, we believe the most ambitious ideas and untethered creativity of young people can help make the world a better place. Doodle 4 Google is meant to inspire students to think and dream big," explained Google on why it chose this year's theme.

Google makes use of doodles on its homepage to surprise and entertain its users. It launched the Doodle 4 Google contest first in the U.S. in 2008 but now the contest also runs in other countries.

"Creating the best doodle comes with major perks: this year - for the first time ever- the winner of the competition will become an honorary Google Doodler for a day and will get to animate his or her Doodle for the homepage with the Doodle team. The winning Doodle will then be featured on the Google homepage for a day for millions to see. If that's not cool enough, the winner will also receive a $30,000 college scholarship and a $50,000 Google for Education technology grant for his or her school," announced Doodle team leader Ryan Germick.

The first round of judging will be done by Googlers with the help of select judges such as The Lego Movie directors Christopher Miller and Phil Lord; "Percy Jackson Series" creator Rick Riordan; author Daniel Handler; astronaut Ron Garan; and robotics designer Lee Magpili, among others.

The company will announce the state finalists on April 29. The finalists will be able to visit the Google campus in California on May 21 for a day of activities and workshops. The national winner will be determined by public vote and will be announced in June.

In 2013, Sabrina Brady from Wisconsin was declared the national winner. Her work featured the homecoming of her father, an American soldier, from his tour of duty in Iraq. She bested more than 130,000 entries from all corners of the U.S. that tried to express last year's theme of "best day ever."

This year, Google partners with Discovery Education to help parents and teachers encourage kids to join the contest through different activities such as video presentation and a virtual field trip to the headquarters of Google. Google Doodlers will also hold online sessions to show students how doodles are conceived, produced, and published. The entry forms can be downloaded here.