The Foldscope can be assembled from a flat sheet of paper in under 10 minutes. “Although it costs less than a dollar in parts, it can provide over 2,000X magnification with submicron resolution, weighs less than two nickels, is small enough to fit in a pocket, requires no external power, and can survive being dropped from a 3-story building or stepped on by a person.”

The device  requires a tiny lens, and to provide light, a 3V button battery, an LED plus a couple of other bits and pieces. The total cost is $0.97, says Prakash. The device is simple to operate. It can be manually adjust with a little skill. And the results are impressive. Prakash and the team show how to use the device in a number of different configurations to achieve brightfield and darkfield images as well as fluorescence microscopy.

Important are applications in healthcare where foldable microscopes could be made disease specific with the right kind of staining and filters. Prakash and co have already shown how their device can image common bacteria and parasites such as Giardia lamblia, Leishmania donovani, Trypanosoma cruzi (Chagas parasite), Escherichia coli and so on. These microscopes could be made disposable to reduce cross contamination and the possibility of infection from highly contagious diseases.

There are a number of opportunities for improvement for the Foldscope. A particular focus (ahem) will be to improve the lenses with modern manufacturing techniques, perhaps making them aspheric to reduce optical aberrations.