(624f) Ultrathin, Free Standing Biomimetic Membranes From the Vapor Phase:

Decomposition of a gas phase initiator into free radicals to facilitate polymerization of a monomer/monomers is the cornerstone of the initiated chemical vapor deposition (iCVD) process that distinguishes it from other types of vapor deposition of polymers. iCVD has been successfully used earlier in our group to deposit a wide variety of conformal coatings with the desired functional groups for varying applications. In this work, for the first time, we have used initiated iCVD to fabricate free standing ultra thin biomimetic membranes. Ultrathin membranes as thin as 100 nm were made by this method. iCVD thus is capable of producing membranes with thicknesses thinner than typical solution based methods such as spin coating. The resulting membranes were characterized for thickness, mechanical robustness and permeability. Various chemistries resulted in membranes with varying mechanical robustness. Potential applications in microfluidic devices will be discussed. Three strategies of device fabrication using iCVD free standing membranes will be explained. Selecting the right chemistry to impart mechanical strength to the free standing membrane while serving its function (gas permeation, liquid barrier etc.) is key to successful applications. Optimizing the handling of the ultra thin free standing membrane during the steps of device fabrication is of paramount importance. This work promises more future research into integrating iCVD into the process flow of biomedical device fabrication entailing biomimetic coatings and free standing membranes.