Hello community, I am currently working on a microfluidic project. In order to detect the shear forces in the outer regions, I wanted to implement micro-pillars. Does somebody have a proper solution of a simple manufacture method of these pillars and to mount them on a very tiny surface (probably a diameter of 200-500 micron, material: PMMS or PMMA). The micro pillars will probably be made of silicone. Unfortunately, I cannot give more information, because I have recently started to work on the project.
Greetings, K.T
Hello Karl, I have fabricated PDMS micropillars of various diameters from (5um to 50um) using photo-lithography on SU8. This process is quite simple as long as you have access to the basic photo-lithography setup. Once the master mould is prepared, you can spin-coat PDMS on it and then degas in vacuum to get pillars standing on a thin layer of PDMS. Also PDMS to PDMS plasma bonding works well for small areas similar to what you have mentioned. Thus the thin layer with pillars can be peeled off the master mould and can be bonded to other surfaces.
Hope this helps. If you need info about pillar fabrication, you can refer to http://dx.doi.org/10.1063/1.4906905
- Siddharth
Here you find the article http://dx.doi.org/10.1063/1.4906905. Good luck.
Hi Karl,
If the material is PMMA, I would suggest to for micromilling to fabricate pillars based on the dimensions you provided. I don't think circular cross section pillars are possible with micromilling, but definitely, you can fabricate rectangular cross section pillars. I recently fabricated 100-micron slots using micromilling. Two normal cuts would result in rectangular pillars.
Good luck.
Hello,
I have gathered some information and I will probably manufacture a mold and then cure PDMS in it.
I have also thought to 3D print the stuctures, but I i am aware of the constancy of the dimensions of the structures.
Maybe possible would also to mill a frozen PDMS block. I thought about a method with liquid nitrogen. Does somebody know if I would change a lot the mechanical abilities of the substrate when I freeze and then defrost it? PDMS on its own is unfortunately too less stiff to become milled.
@Anvesh Gaddam: I am going to use cylinders. They won´t bring so much noise into my measurements. But thank you for the great ideas! In my previous internship we tried to mill silicone sheets and were looking for a very cheap solution. When you bond it on a surface with double-sided adhesive tape and they mill it, it till do a very good job!
Kinds regards,
K.T.
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