anisotropy

Hi Niky, by popular demand I've put them on Etsy: https://www.etsy.com/listing/548186223/the-pocket-...Thanks for your support!

Hi yrralguthrie, my hope was that you could make your own microscope with this Instructable so that you could have one right away! If you don't want to print and assemble one yourself, I've made some available on Etsy: https://www.etsy.com/listing/548186223/the-pocket-...

Hi Ragbear, if you don't want to make one yourself, I've made them available on Etsy: https://www.etsy.com/listing/548186223/the-pocket-...Thanks for your interest in my project!

Hi rflight79, thanks for your comment. It's from the very paper that you linked to that I learned of the Prakash lab's wonderful idea of using glass bearing balls as magnifying optics. I had I had been searching Edmund Optics and Thorlabs for small lenses, but products from any conventional optics supplier aren't in the reasonable price range for an ultra-low cost application.You're right that the Foldscope design is not a secret, but I wouldn't go so far as to say that it's open. To make a Foldscope by yourself from the image in the paper, you need to trace it, create a DXF file, and cut it on a CNC cutter or laser cutter (or be *very* patient with an x-acto knife)-- not really an easy process. Being desperate and short on time, I was almost ready to do this before considering designing…

Hi rflight79, thanks for your comment. It's from the very paper that you linked to that I learned of the Prakash lab's wonderful idea of using glass bearing balls as magnifying optics. I had I had been searching Edmund Optics and Thorlabs for small lenses, but products from any conventional optics supplier aren't in the reasonable price range for an ultra-low cost application.You're right that the Foldscope design is not a secret, but I wouldn't go so far as to say that it's open. To make a Foldscope by yourself from the image in the paper, you need to trace it, create a DXF file, and cut it on a CNC cutter or laser cutter (or be *very* patient with an x-acto knife)-- not really an easy process. Being desperate and short on time, I was almost ready to do this before considering designing my own 3D printed microscope that then resulted in this Instructable. But on top of the cutting challenges, I'm not sure if creating a Foldscope replica would infringe on the Prakash lab's patent (https://patents.google.com/patent/WO2013120091A1/en), since it doesn't seem to have been made explicitly free for anyone to make. Worth a mention: Something else I was considering for my teacher training workshop in Liberia was the trick of using a plastic collimator lens from a laser pointer (such as the "$1 Laser Pointer Hack" on this page: https://www.stemazing.org/stemonthecheap). The magnification leaves something to be desired and you need a phone camera to use it, but I've seen it done and it's pretty neat!

Thanks for the comment! To take the photos, I just held up my phone camera to the lens. All of the photos here were taken using the large lens (80x).

You can use pretty much any CAD program to view STL files and modify them. If you wanted to just view the files, Google "STL viewer"-- there are browser versions and also free downloads.