Application of Micro/Nanoporous Fluoropolymers with Reduced Bioadhesion in Digital Microfluidics
Andreas Goralczyk,
Sagar Bhagwat,
Fadoua Mayoussi,
Niloofar Nekoonam,
Kai Sachsenheimer,
Peilong Hou,
Frederik Kotz-Helmer,
Dorothea Helmer,
Bastian E. Rapp
Affiliations
Andreas Goralczyk
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Sagar Bhagwat
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Fadoua Mayoussi
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Niloofar Nekoonam
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Kai Sachsenheimer
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Peilong Hou
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Frederik Kotz-Helmer
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Dorothea Helmer
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Bastian E. Rapp
Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
Digital microfluidics (DMF) is a versatile platform for conducting a variety of biological and chemical assays. The most commonly used set-up for the actuation of microliter droplets is electrowetting on dielectric (EWOD), where the liquid is moved by an electrostatic force on a dielectric layer. Superhydrophobic materials are promising materials for dielectric layers, especially since the minimum contact between droplet and surface is key for low adhesion of biomolecules, as it causes droplet pinning and cross contamination. However, superhydrophobic surfaces show limitations, such as full wetting transition between Cassie and Wenzel under applied voltage, expensive and complex fabrication and difficult integration into already existing devices. Here we present Fluoropor, a superhydrophobic fluorinated polymer foam with pores on the micro/nanoscale as a dielectric layer in DMF. Fluoropor shows stable wetting properties with no significant changes in the wetting behavior, or full wetting transition, until potentials of 400 V. Furthermore, Fluoropor shows low attachment of biomolecules to the surface upon droplet movement. Due to its simple fabrication process, its resistance to adhesion of biomolecules and the fact it is capable of being integrated and exchanged as thin films into commercial DMF devices, Fluoropor is a promising material for wide application in DMF.