Hwa Chong Institution student Tan Ding Jie and River Valley High School's Gu Tianyu, both 17, spent their year-end school holidays last year experimenting with a 'superhydrophobic membrane' that repels water, like a lotus leaf, while absorbing organic solvents such as oil.

Their project was one of 59 developed last year under the Young Defence Scientists Programme (YDSP), a joint effort between the Defence Science and Technology Agency and DSO National Laboratories.

The annual programme, begun in 1992, helps students venture beyond textbook theories by working with defence technology professionals.

Instead of enjoying time off during the holidays, Ding Jie and Tianyu holed themselves up in the laboratories of the National University of Singapore (NUS) to find the most cost-effective material to absorb grease or oil leaks. They were mentored by scientists from NUS and DSO.

After three months, the pair came up with a recyclable 'sponge' that can also be used to absorb oil leaks in vehicle engines, and keep soldiers as well as vehicles clean in muddy terrain.

'I feel I have achieved so much more in the past few months learning from the best brains,' said Tianyu.

Ding Jie added: 'Its great to know that our research is meaningful and can make a difference to daily life.'

Yesterday, the duo were joined by 108 budding scientists from 12 schools showcasing their works at the YDSP Congress at Orchard Hotel.

Speaking at the event, Defence Minister Teo Chee Hean credited Singapore's 5,000 defence scientists and engineers for putting locally developed technologies on the world map.