Characterization of long‐term stability of hydrophilized PEG‐grafted PDMS within different media for biotechnological and pharmaceutical applications

Poly(dimethylsiloxane) (PDMS) is broadly utilized for the development of disposable lab‐on‐a‐chip systems. For many microfluidic applications hydrophilic surface characteristics are indispensable. In this work, an easy, reliable and stable surface hydrophilization procedure based on poly(ethylene glycol) (PEG)‐silanization is presented that overcomes the hydrophobic nature of PDMS. Furthermore, the long‐term stability of the grafting as well as the effect of different parameters ( e.g ., applied solvent) on the hydrophilicity according to the measured contact angles (CAs) are analyzed within different media. Finally, the successful hydrophilization of different PDMS microfluidic devices and the effect of its performance are demonstrated ( e.g ., in a micro‐emulsification component). magnified image Effect of the surface properties of PDMS‐structured devices on the performance of drop emulsification with regard to the CA: (a) bare, hydrophobic and (b) PEG‐grafted, hydrophilic PDMS.