Bake a lens for pennies a piece

drop lens

It’s not quite as simple as a kid’s Easy Bake Oven, but an Australian University says it’s come up with a new method that makes inexpensive, high-quality lenses by hanging droplets of transparent silicone and curing them in an oven.

A droplet of clear liquid can bend light, acting as a lens — and by exploiting the phenomenon, researchers the Research School of Engineering at Australian National University have developed a new process to create inexpensive high quality lenses that will cost less than a penny apiece. “Because they’re so inexpensive, the lenses can be used in a variety of applications, including tools to detect diseases in the field, scientific research in the lab and optical lenses and microscopes for education in classrooms,” the researcher’s report to the Optical Society says. “It opens up lens fabrication technology.”

Conventional lenses “are made the same way lenses have been made since the days of Isaac Newton—by grinding and polishing a flat disk of glass into a particular curved shape,” the Optical Society comments. “Others are made with more modern methods, such as pouring gel-like materials molds. But both approaches can be expensive and complex. With the new method, the researchers harvest solid lenses of varying focal lengths by hanging and curing droplets of a gel-like material—a simple and inexpensive approach that avoids costly or complicated machinery.”

The new process systematically fine-tunes the curvature that’s formed by a simple droplet with the help of gravity, and without any molds. All that’s needed is an oven, a microscope glass slide and a common, gel-like silicone polymer called polydimethylsiloxane.

The researchers made lenses about a few millimeters thick with a magnification power of 160 times and a resolution of about 4 microns (millionths of a meter)—two times lower in optical resolution than many commercial microscopes, but more than three orders of magnitude lower in cost — low enough to make them disposable.

For example, the researchers built a lens attachment that turns a smartphone camera into a dermascope, which can cost $500 or more; the phone version costs around $2. It is slated to be commercially available in just a few months. A similar smartphone-based tool can also help farmers identify pests out in their fields.

The full paper is here.


About Paul Worthington

Paul Worthington is a journalist and consumer imaging consultant. He produces the annual Future Imaging Summit at PMA@CES, and writes for PMA Newsline and PMA Magazine, as well as other publications.