Performance of multilayered fluoropolymer surface coating for DEP surface microfluidic devices

Abstract

One of the key structural features of a surface microfluidic (SMF) device is the surface coating, since it directly affects both the performance and reliability of the SMF device. This work examines and compares the performance of liquid dielectrophoresis (LDEP) SMF devices, fabricated with conventional spin-coated Teflon® surface to those coated with a recently developed fluoropolymer composite coating, which have been shown to be superior for low-voltage electrowetting actuation. We have focused on SMF devices that leverage LDEP and utilize high AC voltages to actuate aqueous samples on hydrophobic surfaces and produce droplet arrays of controlled size and structure to facilitate rapid and large-scale combinatorial bio-assays. Our findings demonstrate the superior performance, robustness and reliability of the composite coating over the conventional spin-coated Teflon® coating, for repeated high-voltage, high-frequency LDEP actuations for homogenous, emulsion and variable volume aqueous sample dispensing.