A Novel Methodology for Wettability Process Control of Buried Silicon Microchannels for Molecular Diagnostic Applications

Abstract

MEMS technology applied to new materials resulted in new and useful approaches for the fabrication of microchannels intended to be applied in microfluidic devices; the main applications are in the development of diagnostic devices, being versatile and integrable in sensors; small liquid handlers; microreactors for solutions; micropumps; etc. The surface wettability of microchannels walls is a key feature to guarantee the proper samples through the fluidic flow channel. Wettability is a surface property mainly determined by various factors such as surface morphology and surface chemistry. In this paper, we proposed a novel methodology for the measurement of surface wettability of silicon microchannel walls by the direct evaluation of the contact angle (CA); various surface coating and working liquids were also evaluated. In order to correlate the wettability with the microchannel bio-functionality, the polymerase chain reaction (PCR) efficiency in chemically treated microchannels was also evaluated. This methodology appears to be eligible as an innovative and fast process control method for microchannel coating effectiveness verification, mainly for manufacturing purpose and industrial applications.