APTES treatment is also a common strategy for irreversible bonding of nano porous membranes such as PC, polyethersulfone (PES), and polyester terephthalate (PETE) to different substrates for organs-on-chips applications . In this protocol, subsequent to O2 plasma activation, the membrane is submerged in a 5% APTES solution (diluted in DI water) at 80 ℃ for 20 min. Press the APTES treated membrane against a O2 plasma activated layer leads to an irreversible bonding between the layers. It is worth mentioning that corona discharge method is not recommended for hydroxylation of membranes as it could damage the homogeneity of the membrane 110 .