Thanks a lot!

 Hi Jan,

a curiosity, how rigid is the material you want to slice? Did you consider a laser cut for this aim?

Cheers,

Roberto

It will probably be fairly soft (rubber) but this could be change. It should be possible to make it a hard material. Is there a laser cutter device that can do the slicing?

Hi Jan,

spontaneous idea: the work shop can make a metal block with a 1x1 cm depression, 0.5 mm in depth, which will exactly take the sample. You place the sample in the depression, run a razor blade over it and thus split off the protrusion. It's not fancy, but worth trying. See file attached for a rough sketch (the edges of the sample-holder should be much wider than shown). One can also add a cutting movement (momentum parallel to the blade).   

Cheers,

Alexander 

Hi again,

I found some commercial laser cutting machines. They claim that the cut is quite precise and neat. However, I was not able to find in the website what is the size of the cut itself. I think it should not be difficult to get this information from them. I think they can even do the cut without buying the machine. If the sample is soft, it could be possibly necessary to freeze it in liquid nitrogen and then cut it. Hope it helps,

Roberto

https://www.troteclaser.com/it/tutorial-e-formazione/faqs/come-taglio-laser/

Dear Jan,

a lot depends on what you mean with “fairly soft” and what you expect from the new surface, i.e. how smooth and regularly it has to be. The dimensions which you are talking of are almost “anatomical” so I guess that maybe surgical equipment might be useful for you. Surgeons and histologists have a lot of different really very sharp tools ;-) which might work if “fairly soft” is not too hard.

So maybe you could try to cut it with a scalpel and some kind of frame (0.5 mm thickness) as a base socket around your film with which you can lead the scalpel. There are also ultrasonic scalpels available which put the blade into a longitudinal movement.

All the best

Dirk

Hi Jan,

I found another possibility. A friend of mine works in neurology research and they often need to cut very thin slices of rat brains. The procedure they use involves some particular razor blades and devices produced by a company (www.tedpella.com). In the attached file, you can find the procedure and the materials they use. If I understood correctly, they claim that, with some razor blades, a cut of about 100um can be made.

All the best,

Roberto

Dear Roberto, Alexander and Dirk,

Thanks a lot for your helpful suggestions! The inside surface is actually not so important; the key thing is that not too much is removed, because we want to use the two outsides in the end. We might be getting a standard manual microtome for thinner samples (it can do up to 60 microns) and use one of the knife-based approaches for thicker samples. I like Alex's idea with the depression in the metal block very much! I simply like simple solutions to hard problems. ;-) Probably one still needs to figure out a way of pressing the film against the base so it cannot fold, without blocking the path of the knife.

Cheers

/Jan

Dear Jan

An addition to Alex's idea with depression, use of small vacuum (depending upon how soft is the film) can be helpful to hold the film with metal block just like in spin coating machine.

Cheers

Swadesh

Dear Swadesh, Of course! That's the best solution. Thanks for this excellent tip!

/Jan

Hi, I'm glad you like the idea. Here is a solution with readily available parts: One can use a porous ceramic vacuum chuck table (a flat porous device to hold and fix wafers) and  two feeler gauges.The feeler gauges have steel plates of various thicknesses. 200 - 600 µm should absolotely be included.The film along with two parallel plates of the feeler gauges (one each side) are placed on the chuck and will be fixed by suction. A feeler gauge is usually well oiled, so you want to dry and clean it before placing it on the chuck. The advantage is that you can easily adjust to the thickness you wish.

Cheers

Alexander        

Welcome Dear Jan

Kindly update here when you get finalized with the proper setup.

Cheers

Swadesh