An Australian National University scientist has discovered a simple, cheap way of turning a smart phone into a high-resolution microscope, opening the door to a revolution in science and medicine in developing countries. The transformation is made by attaching a tiny lens made of a clear pliable polymer onto the camera lens of a phone, explains inventor Dr Steve Lee, from the Department of Biomedical Engineering. "We make it by putting a droplet of PDMS onto a microscope cover slip and then inverting it. Gravity pulls it into the perfect curvature." "It costs less than a cent, and it's a very reliable fabrication process," Dr Lee says. "The polymer, is the same as that used for contact lenses, it won't break or scratch. It would be perfect for the third world, all you need is a cover slip, some polymer and an oven." Dr Lee has also designed a tiny microscope frame for the lens to fit into, which can be 3D printed. The technology taps into the current citizen science revolution, which is rapidly transforming owners of smart phones into potential scientists. There are also exciting possibilities for remote medical diagnosis. "Already there is interest from a German group with an application to tele-dermatology," says Dr Lee. "There are also possibilities for farmers, they can photograph fungus or insects on their crops, upload the pictures to the internet where a specialist can identify if they are a problem or not." The first droplet lens was made by accident, says Dr Lee. "I nearly threw them away. I happened to mention them to a friend of mine who is a doctor, and he got very excited," Dr Lee says. "So then I decided to try to find the optimum shape, to see how far I could go. When I saw the first image I was like, 'Wow!'" The droplets lenses are able to create a resolution of 3 micrometres with a 5 MP camera? They are made by adding successive tiny amounts of fluid to an initial droplet. "The uniformity of gravity balancing with surface tension makes the droplet the perfect shape," says Dr Lee. "The interplay between the forces at such a fine level is quite beautiful."