The master Lego legends from Terang, Victoria, aged just 15 and 16, will fly to Arkansas in May 2020 to put the skills of their hand-built Lego robot 'Rocky' to the test for the First Lego League.

The Lego League is a competition for upper-primary and lower-secondary school students. Every year, teams of up to 10 students build, program and compete with a robot, while also learning about a modern problem in science and engineering and developing solutions for it.

Rocky is a one-of-kind Lego robot that the siblings designed and programmed themselves with the mission to tackle Australia's landfill crisis.

"Our idea is using a thing called an autoclave, which is like a giant pressure cooker, where all the waste gets cooked and turned into a dry waste which then can be used as a green fuel and can be sorted into plastics and glass to be further recycled," Ben said.

Younger brother Luke said: "We originally decided to do this for our project because we know how much of a problem waste really is and that only half of our recycling gets recycled due to contaminants."

"We made it our focus because if we don't do anything now it's just going to become too big of a problem to handle."

The Terang College students are one of two Aussie teams heading to America to vie for the top gong.