The DropoScope is a water-drop projector that works by projecting a laser through a drop of water, ideally dirty water crawling with microorganisms. With the right adjustments, a bright spot of light is projected onto a nearby wall, revealing a magnified image of the tiny animals within. Single celled organisms show up only as dark spots, but larger creatures like mosquito larvae exhibit definite structure and detail.
While simple in concept and requiring nothing more high-tech than a syringe and a laser pointer, getting useful results can require a lot of fiddly adjustment. But all that is a thing of the past for anyone with access to a laser cutter, thanks to [ingggis]. His design for a laser-cut a fixture lets anyone make and effortlessly adjust their own water-drop projector.
If you’d like to see some microorganisms in action, embedded below is video from a different water-drop projector (one identical in operation, but not lucky enough to benefit from [ingggis]’s design.)
If you’re interested in additional details about water-drop projection microscopes, be sure to check out this paper which is chock-full of useful and practical details.
The Exploratorium in San Francisco had a water drop laser projection microscope in 2016 that controlled the drop size automatically (motorized syringe with optical sensor feedback). The web site results only in an “activity”: https://www.exploratorium.edu/press-office/press-releases/explore-waters-palace-fine-arts-lagoon
When I was a kid at summer camp we did this with an overhead projector, a microscope slide, and a magnifying lens (if my memory is correct – That was over 30 years ago). It’s a neat trick with fun and educational results. It’s really cool that a “home version” has been developed.
“Laser pointer? You have my attention.” ~The cat, probably
Isn’t that the head of a cat peeking up at the bottom center of the video still frame above?
i think that’s Ba’al the soul eater…
Hence my comment :-D
Oh thats a good article
The cat…
I wonder if there is a way to fix the drop with clear acrylic resin so that you end up with a plastic drop with microorganisms embedded in it. Acrylics can be water miscible and would replace the water as the drop dried out. The hack would be to retain the correct shape to have the optics still function as required.
I misread the title as “microorgasms can’t hide…”
The output of that video from the older article one seems much better than the sample picture on this version.
Mind you, that older version’s author says he had bad results with a red LASER which this newer one uses as a sample. So maybe the design is superior but you just need a green pointer.
Poor man version
https://s14.postimg.org/ixbrh5w2p/2017-07-21_12.23.08.jpg