Smartphone DIY Microscope

One projects leftover is another projects raw material :-)

My recent instructable Webcam-mod-for-Astrophotography resulted in the webcam lens being leftover, after searching on Instructables I found quite a few uses for the lens

https://www.instructables.com/id/Microscope-JIG-for...

https://www.instructables.com/id/10-Smartphone-to-d...

and decided to try building a microscope attachment for my mobile phone. I am quite pleased with the magnification, should keep the kids interested. Refer to my previous instructable on how to remove the lens from the webcam.

What I really would have liked is for this project to use laser cut acrylic or polycarbonate sheets with proper rack and pinion focusing mechanism and overall a more portable and sturdy structure. Since I had neither of either I decided to dig up my scrap pile and came up with this contraption that does the job and is quick and easy to make.

The sample photos are

1. A hair follicle
2. Part of a tiny pumpkin leaf
3. Hair on a mosquito leg
4. Hair on a mosquito abdomen
5. Head of the dead mosquito

Its not that I like mosquitoes, its just that its the only insect I felt good about killing and photographing, not to mention easy to find in my apartment.

Materials needed are, 3 old CDs/DVDs, two screws, a rubber band, a means of cutting and making holes in the CDs/DVDs and a microscope slide (thin rectangular piece of glass) for placing specimens.

The picture shows what the whole thing looks like so it is easy to visualize when I explain in the next steps. Essentially it is a large 3 armed clip that you can clip onto the selfie (front) camera of a mobile. This allows you to easily see the magnified image and reposition it if required.

Throughout this instructable I am going to refer to the CDs as top, middle and bottom. The mobile phone is held between the bottom and middle CDs, the lens is attached to the middle CD only and the specimen is placed on the top CD. The pencil and the screws act like hinges for the three CDs. A rubber band holds all three together.

This is the lens I removed from my webcam mod in my previous instructable. The lens assembly can be unscrewed from the housing as shown in the second image. There is usually a bead of glue to hold the focus of the assembly, this can scraped off and the lens unscrewed.

This lens has a very short focal point and the specimen has to be kept almost touching the lens. At the magnification I got, I found that flexing the top CD was enough to change the focus by changing the distance of the specimen from the lens. More on that later.

Start with the middle CD. Place this on the mobile phone and determine where to make a hole so that the lens is over the camera. Also mark and cut the CDs as shown in the second image so that it is not covering the mobile phones screen.

Make holes and insert the screws on either side of the central hub of the CD. The screws should snugly thread through these holes. Make the hole for the lens and screw the lens into it as shown in second image.

Align the top CD over the middle CD and make holes as shown in the 3rd image. These holes are larger so that the screws and the lens move freely through the holes.

Mark two dimples on the bottom CD where the two screws will rest to form the fulcrum as shown in 4th image.

Cut two slits on the inside of the hub of all three CDs to attach the rubber band to hold all the three CDs together like a sandwich. Start with the bottom CD, then the middle and finally the top CD.

Insert the two screws through the two holes in the top CD and screw then through the middle CD. The screws should be tightened so that the gap between the bottom and the middle CDs is almost the same as the thickness of the mobile phone. Do some final adjustments of the screws so that the middle CD is parallel to the bottom CD when the mobile phone is placed between them and the lens is resting on the camera of the phone. This completes the main clip so that everything can be clipped onto a mobile phone.

Next insert a pencil between the top and middle CDs to form the second fulcrum. Pressing the top and middle CDs between your thumb and index finger will allow you to adjust the focus very minutely. I was initially planning to have another screw for focus adjustment but found that the flex of the CD was enough to change the focus of the image seen. Only downside of this is that you loose the focus if you let go of the CDs.

Although in this version of the instructable you need a flat surface to place the phone and CDs on to click the photos, in a future version I plan to make something that is more portable that kids can take to the field. I might also do another version that you can do macro photography with so you don't need to pluck the plants to click their photos. I should also probably add a white led light to illuminate the specimens better.

Hope you have fun seeing the world from a different perspective. Enjoy !