Controlling wettability in paper by atmospheric-pressure microplasma processes to be used in µPAD fabrication

Fundamentals and utilization of solid/ liquid phase boundary interactions on functional surfaces

“…especially PDMS [288], polyacrilates [284] and cellulose [290,291]. It is a common practice to hydrophilize the inherently hydrophobic silicone surfaces via oxidative treatment, however, these surfaces slowly transform back to hydrophobic overtime as the diffusion of lower molecular weight silicone species towards the interface proceeds [288].…”

“…Recently, the cellulose-or paper-based microfluidic systems gained increased attention as a result of their cheapness (does not require special preparation conditions, such as cleanroom etc.) [290][291][292]. As these systems are disposable, they already made their way towards healthcare applications as test kits (e.g.…”

“…Thanks to the presence of OH groups, paper is easy-to-functionalize, e.g. through silanization [290] or plasma deposition [291] to obtain microchannels with varied wettabilities. Li et al modified paper through fluorosilanization and subsequent oxygen plasma treatment [290].…”

Superhydrophobic Paper by Facile and Fast Atmospheric Pressure Plasma Etching

“…However, its inherent hydrophilic character limits its applications and thus a surface modification of paper is needed in order to obtain hydrophobicity or superhydrophobicity. Among the potential applications of superhydrophobic paper are the antibacterial food packaging, water‐oil separation membranes, and the fabrication of inexpensive and disposable paper‐based microfluidics for lab‐on‐chip . Preparation of superhydrophobic paper would be also beneficial to the protection of documents and preservation of cultural heritage …”

“…However, little progress has been made in paper treatment in order to enhance its surface hydrophobicity. Moreover, most of those reports are focused on the direct deposition of a hydrophobic or even superhydrophobic coating on paper substrates without any significant pre‐roughening of cellulose fibers.…”