It is often convenient or aids performance if a single function is created using more than one layer as in the case of some mixer designs. The illustration on the right shows a ‘tree-mixer’, where fluid enters and leaves from the top layer. Fluid entering the middle and
bottom layers is split into a number of parallel streams. The parallel streams of the middle layer flow into and mix with the corresponding streams in the bottom layer, where subsequent flow recombination also takes place. Devices comprising up to 32 parallel mixing streams are available, where the smallest available spacing between adjacent fluid ports is around 1mm.
Multilayer module applications
The combination of bonding and Fluence fluidic interconnection options offers a versatile means for interconnecting multiple microfluidic chips. This enables 2D tiling and 3D stacking of separate microfluidic chips, and greatly enhances overall functionality by building a modular network of microfluidic chips. Including the possibility of macrosystem comprising racks of boards with fluidic backplanes combined if appropriate with electrical, optical, pneumatic backplanes (the equivalent of racks of printed circuit boards). The modular approach allows the systems designer to build more complex microfluidic processes, where individual microfluidic chips act as building blocks or ‘unit operations’. Where fluid throughput requirements are larger, the modular approach also enables ‘scale up by scale out’, where multiple microfluidic processes can occur in parallel.