Microfluidics & Consumables
On-Chip Pump Mechanism
Customer Requirement
Consumables in the diagnostic and IVD market often require active fluid transportation on the chip to realize corresponding complex assay flow schemes. Traditionally, such transport is controlled pneumatically via an instrument. However, with this approach, pneumatic interfaces to the disposable consumable are needed which always involve the risk of critical biological contamination. Especially for molecular assays incorporating the amplification of nucleic acids, a self-contained cartridge is stringently required.
Solution
Depending on the material being used, different on-chip pump mechanisms can be applied to realize fluid transportation in a closed system scenario. One possible solution is the fluid manipulation via one (or more) integrated elastomeric air reservoir, called bellow, realized by a two-component injection molding process. The bellow volume is modified by an instrument-based actuator and due to the hermetically sealed design of the consumable itself, this compression leads to a fluid manipulation. Bellow relaxation on the other hand enables reversal of flow direction. A different approach is the implementation of a thin-film pump, also mechanically operated by the instrument, into a closed-loop fluidic network. Two layers of film being assembled to the consumable are deflected to form a pump cavity and are operated similar to a peristaltic pump. Both solutions are equally well suited for mass manufacturing processes and facilitate completely sealed and self contained cartridge designs as a prerequisite for contamination control.
