Miroslav Michlíček1, Lucie Blahová2, Eva Dvořáková1, David Nečas2, *Lenka Zajíčková2
1Masaryk University, Brno, Czech Republic; 2Brno University of Technology, Brno, Czech Republic
Understanding the role of substrate geometry is vital for successfully optimizing plasma polymerization on non-planar substrates used in bioapplications, such as porous materials or well plates. Previously, we studied the penetration depth, nanoscopic homogeneity and conformality of the atmospheric-pressure plasma polymerization onto an electrospun nanofibrous mat. In this work, we investigated the altered transport of film-forming species and the coatings' properties in a low-pressure discharge of cyclopropylamine and argon mixture. The details were obtained using a combined analysis of the plasma polymer deposition on flat silicon pieces, culture wells, microtrenches, a macrocavity, porous hydroxyapatite scaffolds, and electrospun polycaprolactone nanofibrous mats. The aspect ratio of the well structures impacted mainly the deposition rate, whereas the film chemistry was affected only moderately. A considerable deposition penetration depth into the porous media indicated a relatively low sticking probability of film-forming species. A detailed analysis of microtrench step coverage and macrocavity deposition revealed that there are at least two populations of film forming species with two different sticking probabilities. The presented methodology is widely applicable for understanding the plasma-surface interactions and the plasma polymerization onto complex substrates.