OpenFlexure Microscope, an open-source optical microscope

5 years ago (openflexure.org)

Is it just the my lack of coffee or did they manage to build a website for a microscope without one single example picture taken with that device?

The Foldscope Project has been an interesting one-- a low-cost microscope made primarily from paper, offering 140x magnification: https://www.foldscope.com/

"Foldscope Instruments Inc’s mission is to break down the price barrier between people & the curiosity and excitement of scientific exploration!"

Isn't that a digital microscope? I thought an optical microscope would be one that just uses lenses and eyepieces to magnify and show the images to one or more eyes.

Maybe I've missed something. It looks cool - but I'm not sure I understand what the purpose of OpenFlexure is from reading the website, what does it do that an old fashioned optical/mechanical microscope doesn't (or one with a digital eyepiece)? Is this meant to find things automatically?

  • "Flexture" refers to the type of mechanism that moves the sample stage relative to the objective lens. It means that instead of a high precision rack-and-pinion gear system that moves the stage, it uses "flexure joints" which don't necessarily need to be precision machined (they can be 3D printed).

    In a flexture mechanism you apply force to a flexible bar and, because of geometry, that displacement gets translated and reduced into a much smaller displacement somewhere else. It only works with very small displacements (thus fine for microscopy). If you want to position the sample large distances, you just need to move the sample.

    It's a neat idea made inexpensive by 3D printing, but the major expense here will be the optics (the objective lens). To get decent pictures of cells, like in a textbook, you're talking about $1K minimum, and it can go much higher, into the 10's, depending on application, performance and other optics (the light source and it's lenses).

    • Is it possible to use software to post process those images, apply a deconvolution filter and correct the optics?

      Might that enable the use of cheaper lenses?

      6 replies →

    • No, a very good Chinese made RMS objective can cost less than $25 at lower magnification. Plan Achromatic objectives cost a little more, but will give flatter, clearer images than cheaper ones.

      It seems a tube lens is used anyway, so the advantages of infinity system objectives are not as obvious. I’d stick to DIN160 or so called Olympus compatible objectives.

    • You'd be surprised at what you can accomplish with a couple hundred dollar plan achromat objective. (Though OpenFlexure's design complicates the use of immersion oil...)

  • "Optical" when talking about microscopes means it's using visible light rather than, say, electrons.

  • The main value of this is a low-cost precision positioning system that can be 3d-printed. A lot of the challenge of microscopy is getting the sample into the right place. And yes, this design can be motorised and controlled automatically as well.

Earlier iterations of this were used successfully as part of a water quality monitoring in Tanzania:

https://www.waterscope.org/about-us/

Richard Bowman (previously Cambridge uni, now Bath) was the main driver of these microscopes and is a great, highly intelligent person. Many other people have contributed to the project in small and large ways over the years.

Some other links:

https://3dprint.com/165457/openflexure-3d-printed-microscope...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7249832/

This is a super cool project. Though I think the website could be a lot more upfront about what is needed to make this and what this can accomplish. A quick list of pats, estimated cost, specs and a sample photo would be really helpful in assessing whether this is a better deal that a $150 used microscope. As it is, it takes three clicks to find the list of parts required and no cost estimates are offered. https://build.openflexure.org/openflexure-microscope/v6.1.5/...

On first glance it appears to be vaporware but there is at least one published image apparently created with the device:

https://openflexure.discourse.group/t/sharing-an-almost-whol...