Polymer Laminate Technology
Microfluidics is a framework of micro- or nano-size channels enabling fluid flow for separation and analysis of macromolecules. The test cartridges within the device enable various functions such as automatic sampling, sample transport, any necessary chemical reactions, and detection on a single, miniaturized platform.
The advantages of microfluidics clearly support the needs of modern diagnostics by offering faster separations, shorter transport time, lower sample and reagent consumption, and the possibility of multicomponent testing under the same conditions.
To truly serve diagnostic needs, however, microfluidic platforms need to deliver fully integrated micrometer-scale systems, while maintaining biological compatibility, biomolecule stability, and extremely sensitive detection.
Material properties impact not just mechanical performance but also fluid behavior. The surface energy and geometry of the channel features also influence the fluid flow. Therefore, the choice of material and design of the cartridge and device are of paramount importance. But the huge amount of materials available for microstructure fabrication makes the selection difficult, especially for those not intimately familiar with polymer chemistry.
“Innovations are required from microfluidics manufacturers to reduce the price per cartridge from a typical $20 to a more sustainable price of $5 at launch, and further to $1.00 or less at high volumes,” comments Leanne Levine, founder of ALine.
“Such innovations come not only from novel materials, but also from integrated design-build-supply capabilities. This has necessitated a paradigm shift from silos of expertise in microfabrication to a wholly integrated manufacturing infrastructure.”
ALine’s mission is to innovate microfluidic platform enginering by vertically integrating a full suite of necessary functions, including novel material technology (polymer laminate; PLT), rapid prototyping, manufacturing, and the supply chain network.
The PLT process begins with a 2-D CAD design “split” into necessary layers, 12.5 micron to 3 mm thick. The layers are designed to incorporate necessary microfluidics features such as channels, valves, pumps, and filters. Different stock polymer materials can be used for each layer. The layers are cut with CO2 gas lasers and stacked and bonded using pressure-sensitive adhesives.
ALine’s fabrication approach simplifies connection to the valves, membranes, sensors, and other interfaces. “The eSENSOR® Genotyping cartridge for warfarin sensitivity testing developed by ALine and GenMark Diagnostics combines polymer laminate layers containing complex fluid channels with the injection molded part for sample loading and the electrical sensor circuit,” Dr. Levine continues.
“This product required numerous design iterations to empirically optimize pumping functions and material selection. But now we have the capacity to produce 25,000 parts per month in our current facility.”