OpenOPTI (A cheap open-source 3D Microscope)

Optical Projection Tomography (OPT) uses similar reconstruction methods as CT x-ray imaging but with visible light for microscoping samples. By taking hundreds of pictures of a sample from every angle of rotation, a 3D representation of that sample can be obtained with the focus and clarity of traditional microscopes without the need for destructive physical sectioning.

There are many ways of doing this, however in the name of simplicity and frugality I went with the most basic approach here to start with. The rig consists of: a USB microscope ($20), mirror ($1), stepper motor ($15), EasyDriver stepper motor driver($7), 10W LED ($8), variable buck-converter ($2), Arduino Nano ($4), and small AC/DC power supply ($5). (So ~$60 total.)

Steps to run:

1. Install the arduino firmware
2. Install the Matlab CT Reconstruction Package Add-on (https://www.mathworks.com/matlabcentral/fileexchange/35548-3d-cone-beam-ct--cbct--projection-backprojection-fdk--iterative-reconstruction-matla