Manu Prakash is the leader of the lab that has been designing and releasing hardware around microscopy for some years. The foldscope is a great paper-based microscope . However, the lab receives more press coverage than what, I believe, deserves.
Many of the projects released by the lab claim to be Open Hardware or open source , but it is impossible to get a hold to their original files. For example, the octopi microscope does not provide source files, the PlanktonScope has build instructions but not the profiles to laser cut.
One fundamental limitation to their approach is that sometimes they reuse parts 'commonly available', such as with the hand centrifuge. If you use one particular toy in your design, people won't be able to replicate it. What are the chances of getting the same toy?