Consumables
Manufacturing

We prefer COP or COC, but also other materials are possible like PP, PC, PMMA. The advantage of COC and COP is the fact, that these materials have been proven to provide a high accuracy in molding and to lead to a high reproducibility of microfluidic or nanostructured parts. Additionally these materials are known for their low protein adsorption despite of their hydrophobic chemical structure.

Photolithography enables us to create smooth surfaces with very low roughness and small structures down to few µm. With our special process we can provide three height levels on one chip as well as a different side wall angle for each level. The side wall angle can be adapted between 1° and approx. 15°, preferably we like to work with 3°-5°. With photolithography we can realize aspect ratios as high as 10:1, e.g. pillars with a height of 60 µm and a width of 6 µm at the top. 

In case your design needs more height levels, we can use micro-milling. Micro-milling has the advantage of giving us flexibility on structure depths, but is restricted in resolution, roughness, side wall angles and edge-radius of channels. In case you need very small structures in nm regime, other mastering technologies are required like e-beam writing. In this case we will realize your project together with our partners.

Typical molding thicknesses are between 0.6-1.2 mm. We typically add larger interfaces or reservoirs as a 3^rd non-critical layer to enable higher flexibility. If heat transfer is critical e.g. for thermo-cycling, a thin foil can be used (e.g.~ 100µm, unstructured).   

It has been proven for a lot of our products that a solvent assisted thermal bonding process leads to high precision bonding and to a very good seal of microchannels, flow cells or other structures. The solvent supported bonding enables us to achieve a stronger and more accurate bond already at lower temperatures, which avoids deformation of the microstructures, loss in structure height and usually minimizes bending of the parts. Our bonded products typically have a flatness of around 100-200µm flatness over the full length of the part (e.g. 75mm) or around 3-6µm/mm (maximum). Such parts can be easily clamped down in the instrument to enable a better flatness and heat transfer.

We usually use CVD processes for coating of SiO₂ –coated surfaces with aminosilanes to achieve a monolayer. Liquid coating is also possible, but we try to avoid this because the aminosilane tends to crosslink and polymerize on the surface. Therefore the coating becomes thicker and less uniform. In the CVD process we can tune the parameters in a way that larger agglomerates do not go into vapor phase.