High-resolution, upside-down microscope for oil immersion

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Hi everyone we are planning on turning the microscope lens upside down (turn 180 degrees on the vertical access) so that during oil immersion microscopy, oil does not drip down. This would also involve switching the position of the light source. @Marco and me would like to work on such an adaptation. Has anybody attempted such a modification? Does anybody know if there is an assembly file for the high resolution microscope where all part are included in one file (e.g. lenses, sensor and motors)? We have seen this file but have not found such an assembly view in the file format .stp or .stl. We look forward to your help.

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The individual parts are currently separate in the repository. If you look at the project on Gitlab, issue #168 has an example of putting them together using NopSCADlib. It is possible but not simple.

If you change the microscope from inverted to upright by switching the illumination and lens that will make it very tall. Also the mounting for the lens will be far from the mounting for the x-y. I would worry about stability. Plastic is good when it is small, and in the current design the x-y and the z movement is all very close coupled. This way it is less likely for them to wobble independently. If they all wobble together, the image stays fixed.

What might be worth trying is to just put the whole microscope upsidedown. Imagine screwing the base to the underside of the table instead of to the top of the table. That I think should work without major design changes.

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Also consider the delta stage, which might have some properties which could be useful for your case.

Also I can confirm that operating the microscope just turned upside down works also quite well. You could just design a special slide holder and you are good to go.

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Good to know it does work upsidedown :slight_smile:.

The Delta Stage might well help with designing an upright microscope version. It has more of a casing around the legs that could be extended upwards. The mounting of the (heavy) lens up top will always be far from the mounting of the legs. That needs a very stiff structure, especially with the resolution and small depth of field of a x100 lens.

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Thank you all for your help. The stiffness of the structure and the vibrations will not doubt be a challenge. We might have to put some more thought into that. We would really like the upright version in order for handling of the oil immersion to be easier for the user. We will get back to you as soon as we have put some more thought into the idea.

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You’ve probably considered this but the oil issue is usually tackled in microscope facilities by encouraging users to apply very small amounts of oil and also by putting something around the objective to soak up any stray drips. This is often a child’s hair scrunchy. I’ve seen some particularly frilly scrunchies on some very fancy microscopes!

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Hi - the immersion oil is pretty viscous, and so I never had an issue with inverted microscope operation. Note you typically are looking through the 0.17 mm coverslip, so you may want to build a mount just for those if you don’t want to sandwich your sample with a glass slide.

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Hi everyone

We @Marco have tried a couple of things and received some tips from @MboaLab. First we attached the illumination dovetail only with magnets, so we can easily remove it to apply the immersion oil. So far it has worked quite well and we are thinking of fixing the dovetails position with indents. Attached some pictures that show how we stuck (using super glue) small magnets on the illumination dovetail to attach it to the microscope.

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IMG_20634032×3024 2.12 MB
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IMG_20614032×3024 2 MB

The further pictures show the technique of applying immersion oil on the microscope using a scrunchy or tape to stop oil from dropping (thank you @david & @MboaLab).

Tips from @MboaLab:

  • Watch oil droplet form;
    1-Watch oil droplet form

  • Touch oil droplet to the lens;
    2-Touch oil droplet to lens

  • Oil should not drip down the lens;

  • Place sample on stage;

  • Raise lens until oil spreads across;
    6-Raise lens until oil spreads across

  • Do not add more oil before putting in the next sample;

  • After the experiment wipe oil off of the metal surface that has drip down with a lens paper and never put pressure on the lens with fingers.

I hope it helps.

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