Australasian Science: Australia's authority on science since 1938

Smartphones as Microscopes

Australian scientists have invented a simple and cheap way of making a high-powered disposable lens that can transform a smartphone into a high-resolution microscope. Costing less than a cent, the lenses promise to revolutionise science and medicine in developing countries and remote areas.

The lens fabrication technique, which has been described in Biomedical Optics Express, was invented by Dr Steve Lee from the Australian National University and Dr Tri Phan from the Garvan Institute of Medical Research.

The lenses are made by using the natural shape of liquid droplets. “We put a droplet of polymer onto a microscope cover slip and then invert it,” Lee said. “Then we let gravity do the work to pull it into the perfect curvature. By successively adding small amounts of fluid to the droplet, we discovered that we can reach a magnifying power of up to 160 times with an imaging resolution of 4 µm.”

The polymer, polydimethylsiloxane, is used for contact lenses and won’t break or scratch. “It would be perfect for the Third World – all you need is a fine-tipped tool, a cover slip, some polymer and an oven,” Lee said.

Lee and his team worked with Phan to design a lightweight 3D-printable frame to hold the lens in place, along with a couple of miniature LED lights for illumination and a coin battery.

Phan said the tiny microscope has a wide range of potential uses, particularly if coupled with the right smartphone apps. “This is a whole new era of miniaturisation and portability. Image analysis software could instantly transform most smartphones into sophisticated mobile laboratories,” Phan said. “I am most able to see the potential for this device in the practice of medicine, although I am sure specialists in other fields will immediately see its value for them.”

Lee said the low-cost lens had already attracted interest from a German group interested in using disposable lenses for tele­dermatology. “There are also possibilities for farmers,” he said. “They can photograph fungus or insects on their crops, and upload the pictures to the internet where a specialist can identify if they are a problem or not.”