Surface patterning strategies for microfluidic applications based on functionalized poly-p-xylylenes

Microfluidic systems require precise surface modification in order to tailor the interfacial properties. For instance, in lab-on-a-chip research, defined surface chemistry is key to minimizing contamination and to increasing signal-to-noise ratios for bioconjugation schemes. Device efficiency and analytical output can also be maximized with devices that have defined surfaces. Similarly, minimizing biofouling is also crucial to suppress background noise and ensure device functions. Once defined, surface properties have been engineered, microstructuring of surfaces can provide defined microenvironments for cell-based culture systems. In this report, we highlight the use of functionalized poly-p-xylylenes for surface modification with a specific focus on microfluidic systems. Functionalized poly-p-xylylenes constitute a versatile group of reactive coatings that can provide a defined chemical makeup of substrate surfaces irrespective of underlying bulk material properties. Recent advances using reactive coatings for surface modification of microfluidics are introduced, including use as nonfouling coatings, fabrication of patterned surfaces, functionalization of previously assembled devices, as well as device-bonding applications.