This DIY Microscope Design Is All Wet

[Robert Murray-Smith] wanted to recreate how some ancient microscopes worked: with a drop of water as a lens. The idea is that the meniscus of a drop of water will work as a lens. This works because of surface tension and by controlling the attraction of the water to the surface,  you can actually form convex and concave surfaces.

What’s interesting is that this doesn’t require a lot of equipment. Some plastic, a hole punch, some pens, a flashlight, and some other odds and ends. Then it’s just a matter of grabbing some puddle water and examining the critters inside. Of course, with a single lens, these are more properly magnifying glasses. Some claim that people in China built such instruments thousands of years ago. [Robert] mentions [Antonie van Leeuwenhoek] as the father of the microscope, although he wasn’t the first to build such a device. He did create amazing glass lenses using a method he kept secret but has been worked out using modern science.

It is hard to see much through the camera, but it clearly was magnifying. Not a bad little rainy day kid’s project since you probably have everything you need on hand. We wonder what other readily-available things you could image with a device like this.

Of course, if you want to build a real microscope, the designs are out there. You can even make one using — mostly — LEGO.

5 thoughts on “This DIY Microscope Design Is All Wet

  1. I think a very old “The Amateur Scientist” article (CD available at showed how to make a glass-droplet microscope of the same sort. Center of a glass rod heated in a gas flame, pull apart to create a very thin fiber. Break in half, heat the end of the fiber again to melt the glass into a tiny ball. More permanent than a water droplet and the size should be a little easier to control. But the fiber attached to the glass ball might distort the image somewhat.

    1. It’s neat that you can make your own. Small precision glass spheres are fairly cheap and are used in the foldscope, for example. Have low expectations on image quality though. Using a laser to illuminate a hanging water drop and project an image works ok and is easier. The best part is that a bunch of people can see it at the same time.

    1. Things like this should be in kids science books, a kid can’t build and electron microscope but he can build this, and this might lead him on a path where he’ll end up building an electron microscope.

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