(188p) Surface Modification Via Initiated Chemical Vapor Deposition (iCVD) for MEMS Application

In the past few decades, development in microelectromechanical systems (MEMS) has provided a distinct opportunity in biomedical device fabrication. Interest in MEMS for biological applications has been increasing rapidly. Areas of research and applications in MEMS include diagnostics, microfluidics, surface modification, novel materials, drug delivery, etc. Surface modification of a MEMS device facilitates the incorporation of multiple functionalities and provides the ability to tune surface energy, to enable subsequent chemical attachment of desirable molecules, or to covalently bind micro- or nanoparticles to the surface.

The initiated chemical vapor deposition (iCVD) method has shown great promise as a surface modification technique, and it has successfully been used to create many distinct homopolymers, random copolymers, and alternating copolymers using free radical polymerization. It is chemically comparable to solution-phase polymerization but is environmentally friendly, able to achieve good conformality, and able to maintain the chemical functionality in the monomers.

In this work, we proposed a novel adhesive bonding method utilizing iCVD which enables strong sealing for polymer-based microfluidic devices as well as the deposition of reactive polymeric nanocoating within complex microgeometries. The nanoadhesive films showed strong and conformal adhesion on the substrates with complex geometries. Bonded devices are able to withstand pressure higher than 150 psia and the all-iCVD nanoadhesive bonding process displays superior resistance against hydrolytic degradation. We've successfully grown both E-coli and myocytes in the iCVD bonded chips and the chip lasted throughout the whole growth and over 2 weeks. Within the channels of the bonded devices, the epoxy and amine groups remain available for subsequent functionalization. A sensor utilizing the epoxy functionality was also developed.