Large area polymer replication for microfluidic devices

Mathias Heckele1), Andreas Gerlach3), Andreas Guber1), Thomas Schaller2)

1)Forschungszentrum Karlsruhe, Institut für Mikrostrukturtechnik,
Postfach 3640, 76021 Karlsruhe (Germany)
2)Forschungszentrum Karlsruhe, Hauptabteilung Versuchstechnik,
Postfach 3640, 76021 Karlsruhe (Germany)
3)Greiner Bio-One, Maybachstrasse 2, 72636 Frickenhausen (Germany)
Mathias Heckele
Forschungszentrum Karlsruhe, Institut für Mikrostrukturtechnik, Postfach 3640, 76021 Karlsruhe (Germany)

mail to: phone: +49 (7247) 822512 / fax: +49 (7247) 824331

A huge market development is expected for modern drug discovery and genomic analysis when rapid parallel analysis of a large number of samples gets available at affordable costs.. The state of the art shows that low cost devices can be fabricated in mass production by micromolding of polymers. In close collaboration, Greiner Bio-One and Forschungszentrum Karlsruhe have developed a single-use plastic microfluidic capillary electrophoresis (CE) array in the standardized microplate footprint. This paper presents the results of experiences which show that hot embossing with a mechanically micromachined molding tool is the appropriate technology for low cost mass fabrication. A subsequent sealing of the microchannels allows sub-microliter sample volumes in 96-channel multiplexed microstructures.

Microfluidic devices fabricated by mass production offer an immense potential of applications such as high-throughput screening in drug discovery, clinical diagnostics and gene analysis [Fehler! Verweisquelle konnte nicht gefunden werden.]. The low unit production costs of plastic substrates make it possible to produce single-use devices, eliminating the need for cleaning and reuse [Fehler! Verweisquelle konnte nicht gefunden werden.]. In addition an increase in value can be generated by the integration of additional functionality by the huge variety of polymer properties. A fabrication technology must also respect the requirements in quality of such fluidic and capillary devices. Precise reproduction of shape and exactitude of measure are imperative for applications with quantitative measurements. This precision must be achieved over the entire surface of a 4" wafer or even rectangular shapes with approx. 86 x 128 mm˛. These large scale areas are required to get a maximum yield of microstructured components to a given standard size. Using the hot embossing technology thin microstructured polymer sheets of this formats can be realized with the required quality [Fehler! Verweisquelle konnte nicht gefunden werden.].

To realize a useful device for the application in life sciences close collaborations of research laboratories and industry are essential. In our case, Greiner Bio-One and Forschungszentrum Karlsruhe (FZK) have entered in a long-term collaboration. Greiner's expertise in high quality molding of plastic disposables with a special focus on miniaturization and FZK as one of the leading German research laboratories in microsystems technology have agreed to partner their intellectual property to fabricate single-use plastic microfluidic devices in standardized or customized formats by hot embossing. Depending on its intended use special surface modifications or coatings of the microchannels can be performed.

Keywords: High-Throughput-Screening, Capillary-Electrophoresis, Microtiterplate, Mechanical Micromachining, Hot Embossing, Compression molding, Sealing