Biofunctional Coatings for Plastic Microfluidic Channels

Swiss medical moulders at Weidmann are boasting an improved process for manufacturing microstructured channels in microfluidics, specifically a method to develop customised coatings.

According to the company, the technology is possible thanks to advances in machining, enabling processors to abandon the use of complex lithographic procedures.

Among a diversity of common surface treatments for plastics, specific functionalisation is a scarce commodity, although it is easy to deposit a standard functionalisation for biomolecules within microstructured systems.

Weidmann says that new customised functionalisation, such as that gained from the AziGrip4 brand of biofunctional coatings from Liechtenstein-based optical coatings company Optics Balzers, will provide customer benefits. Although the coating is customised, Weidmann are experienced in its application. The surface can be functionalised in a short time by dipping, brushing, spraying or rolling. In a first step an adhesion promoter and subsequently the functional polymer will be applied. A few seconds of UV illumination for activation are required.

In addition to the well-established methods for the bonding, for example thermal, solvent or primer bonding, more and more spotting and dispensing of PSA (pressure sensitive adhesive) is applied, because it is flexible aligning to the geometry of the microfluidic channels. Minimal differences in the surface level caused by interleaved mould inserts can be resolved and leakage along the parting lines is prevented.