Surface Modification of PEEK with Gas Cluster Ion Beam Irradiation

In this study, we investigated surface modification of poly ether ether ketone (PEEK) with gas cluster ion beam (GCIB) irradiation. Since GCIB induces high energy density on the irradiated surface, only surface layer is physically or chemically modified without introducing damages in the bulk substrate. The contact angle of water on PEEK decreased with the acceleration voltage of O
₂
-GCIB, which indicated the improvement of hydrophilicity. This increase of hydrophilicity might be explained by increase of hydrophilic group and microstructure on PEEK surface. Preliminary experiments of cell adhesion tests on PEEK with O
₂
-GCIB irradiation showed 25% increase of cell adhesion compared to pristine PEEK substrates.