Lego Working Microscope

A working lego microscope using a water drop, with dual light with down shutter.

Download the free instructions of this Lego Technic Creation :


A small machine, with several possibilities ! I have had this idea by watching a water drop fall on my smartphone screen, which causes a magnification of the pixel, then I wanted to reproduce it in lego version in order to magnification various sample.


The basic functioning uses water drop located on the lens panel. Its causes a magnification of the sample in the light tunnel using the diffraction of the water drop. The magnification adjustment knob operates a worm screw gearing which makes the light tunnel and lens panel go up and down. It is used to set the focus and set the magnification, the more the tunnel is up, the more is the magnification, but the more is the visual sample deformation on the ends of water drop.


The lower and upper light are here to illuminate the sample. The upper light to illuminate the sample and the lower to see the edge. The lower light is very useful with transparent sample (like plant leaf, sugar or fabric) because it makes more brightness to the sample and its edge. But it is useless with solid sample, that is why there is a light shutter to shut the lower light. The maximum magnification is about x5, but it depends of the height of the water drop. That is why I advise you to use cold water with no impurities and try to make the bigger water drop in order to have best magnification. Check the picture below to see the effect of magnification on sample and deformations which occur.

(click to enlarge)

Video and Pictures

See it in action to understand more :

Building Instructions


I have also made free building instructions with professional looking. Threfore, build you own microscope and then send me some pictures of your sample result on my facebook page 🙂

You can download it for free here :

or browsing the blog :

Here is the bill of material :


(indexed also to the rebrickable database)

Some advice to have good magnification :

  • Have the glasses clean (up and down)
  • Have a charged battery (to have the maximum of light)
  • Use flat sample in preference
  • Try to make the bigger water drop
  • Use cold water for the water drop
  • Limit the impurity in the water drop
  • Set the water drop on the center of the light tunnel

Have a good experience 🙂


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