How do you see the almost-invisible? First, you build a better flashlight.

Professor Dayong Jin has built some of the best – and smallest – flashlights in the world, and is using them to watch bacteria and viruses in action, and pick out single cancer cells among millions of healthy ones, potentially paving the way for a range of new, molecular-level therapies.

For his flashlights and 14 years of other interdisciplinary work, Professor Jin has won the $50,000 Malcolm McIntosh Prize for Physical Scientist of the Year.

The award – one of the Prime Minister's Prizes for Science – was presented at a ceremony in Canberra on Wednesday.