Nicholls received US$75,000 as winner of the Gordon E. Moore Award for his his fully-autonomous robotic window cleaner that is designed to reduce human injury and decrease the costs of window cleaning on medium-rise commercial buildings.
The small robotic device uses drones, motors and propellers to navigate building facades and clean windows using water and micro-fibre scrubbers.
Nicholls is the 2018 BHP Billiton Foundation Science and Engineering Award winner.
CSIRO Education and Outreach director Mary Mulcahy said it was another example of Australia's great science being recognised on the global stage.
"Australia is one of the best places in the world to start a career in science, technology, engineering and mathematics. By having our high school students winning international awards, we are further strengthening our international reputation as an innovative country," she said.
BHP Billiton Foundation executive director James Ensor said seeing Australian high school students winning at an international level would inspire others to pursue independent research projects.
"Studying STEM topics fosters innovative thinking and problem-solving abilities that will help to address sustainable development challenges," he said.
"We believe that by supporting STEM education and achievement in young people, we are investing in Australia's future problem solvers."