Polycarbonate (PC) Molding Microfluidics Setup

What is the actual problem, that the PC molding setup will fix, versus the “classic” PDMS chips?

PDMS is also convenient, but it has trade-offs: it is not compatible with many chemicals, has a high permeability to gases, and has a relatively low throughput. The PC molding solution is simply one that MIC considers a way to preserve the spirit of rapid iteration in microfluidics while moving to a more difficult-to-manufacture thermoplastic path. It is aimed at teams that desire machines that act more like actual engineering components (stiff, hard, consistent) and not squashy elastomers.

What is the time needed to manufacture a polycarbonate microfluidic chip using this system?

It takes approximately 1 hour to manufacture PC chips (including molding/embossing to finishing and sealing) assuming that you are starting with an existing mold and you have the major hardware already assembled.

Should I use a cleanroom to PC mold microfabrication?

No, that is one of the points of the headline. This is intended to be done in a place that is not in a clean room and this is significant to European labs who do not want to meter out each generation on shared cleanroom times (or consortia partners who require reproducible fabrication but do not want to have a heavy infrastructure).

What is the rudimentary logic of fabrication- what is different about PDMS?

PDMS normally implies: mix + degas, pour on mold, cure, demold, punch inlets, plasma bond to glass.

The transition to a thermoplastic manufacturing process is the focus of PC molding: the cumbersome stage of curing elastomer is substituted with hot embossing; the chips are prepared with drilling tools; and finally, a plasma cleaner and a laminator are used to close the seal. Practically, that is the way to achieve speed and more solid objects without transforming your laboratory into a microfabrication plant.

What is so good about polycarbonate as a microfluidic material (and when should it be a bad choice)?

PC is said to be optically transparent, mechanically robust and thermally stable with a broad chemical resistance and biocompatibility. The said properties are what make it frequently used when you are concerned with a higher pressure, mechanical life, or a more industrial handling. It is also commercially available, but it is unobtrusive in terms of scaling and repeatability.

In which case it is a bad idea: when you demand a highly solvent-selective profile of solvents, or an autofluorescence level close to zero, you will want to check this early against your optics/chemistry requirements (PC is great, but not magic).

What decision can I possibly achieve in the microchannels?

Channel widths to 15 um with aspect ratio of 2:1 (a low-end resolution standard) have been reported by MIC reports. It would be sufficient already to a lot of cell-handling, transport, gradients, and many lab-on-chip architectures- particularly when you are not aiming to make showpieces in the area of ultra-fine lithography.

What is the tolerance of the pressure of using these PC devices?

According to internal MIC testing, the devices can withstand a pressure of 3.5 bar. Granted, you run your experiments near that limit (or even make aggressive flow transients), then it is prudent to consider 3.5 bar as a known reference point, as opposed to a design point and to discuss margins, fittings, and sealing strategy with the team.

What are the practical contents of the equipment comprised by the “setup”?

The basic hardware is simple and deliberately lab-friendly:

-Heat press with two heating plates: 420 x 550 x 680 mm, maximum temperature 300 °C, and pressure 0-25 tons.

-Laminator: size 270 x 545 x 130 mm, laminated maximum width 335 mm, laminated maximum thickness 35 mm, maximum temperature 140 °C.

-Optional: drilling machine

-Materials Fireproofing: polycarbonate sheets.

Is it provided in the process of fabrication of the mold, or do I have to provide my own mold?

The system concentrates on fabrication and bonding of chips out of an existing mold. With these words said, MIC also expressly states that they can recommend how to make your own molds- which is often the actual bottleneck in shifting teams away off PDMS (where molds are often made in-house through soft lithography) and thermoplastics (where the subject of mold strategy turns into a design and manufacturing choice).

What is the closing / sealing of the chip and whether it can be microscoped (inverted microscopy also?)

To close it down, MIC suggests that you can close PC chips with:

-a thermoplastic slide, or

-a microscope glass slide, or

-a polymer slide that is microscopy-compatible.

And yes, PC is optically transparent to the eye, and “commonly suited to microscopy,” which encompasses the general requirements of inverted microscope operations (unless you select an incompatible bottom substrate and thickness to use as your objective working distance).

What are the alternative possibilities (when I am not certain PC is the correct choice)?

MIC also focuses on PC molding together with other thermoplastic applications such as PMMA device station, Polystyrene (PS) molding, and COC polymer molding. That can be useful in the real-world project context, in which you can select materials based on what is most important (optics, chemistry, mechanical robustness, biological use-case, supply chain), but still maintain something like a fast, no cleanroom mentality.