Adhesion between modified and unmodified poly(dimethylsiloxane) layers for a biomedical application

Surface and bulk modification techniques of poly(dimethylsiloxane) (PDMS) polymers were used to develop a new intra-cochlear electrode for close hugging of inner wall of scala tympani. Laser-induced surface grafting of poly(2-hydroxyethyl methacrylate) (PHEMA) and sequential method for preparation of interpenetrating polymer networks of PDMS/PHEMA were, respectively, used for surface and bulk modifications. The modified PDMS samples were studied by performing attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle measurement, and peel strength tests. The role of adhesion between modified and unmodified PDMS layers on the performances of two-layer structures was studied with peel strength test. The actual-sized fabricated electrodes were assessed inside a transparent model of scala tympani that was filled with saline.