Laser controlled multifunctionalization of polymer surfaces for industrial applications

Abstract

The use of biocompatible polymers in the field of bio-engineering is dominated by the surface properties of the device material. Much effort has been extended on modifying material surface properties, to control the bioactivity. While polymers are important materials in industry and research, their applications are limited by poor adhesion and wettability. This paper focuses on modifying the surface properties of the polymers namely polyimide and silicone by using diode-pumped solid-state laser through Laser Modification-Direct Writing (LaM-DW) technique, for the application in electrodes of cochlear implants (CI). In case of cochlear implants the interaction to the cells of the connecting tissue is important. After implantation of the CI electrode, due to the growth of the connected tissue the electrical stimulation signal becomes unspecific. The aim is to develop an implant surface which improves the adhesion property between the electrode interface and the connected tissue, and at the same time reduces the neuronal cell growth on the CI electrode. The adapted strategy is to modify the polymer surfaces at a fluence level below the ablation threshold. By applying only small changes to the laser structuring parameters, polymers can exhibit dramatic changes in wetting characteristics, allowing surfaces to be selective (hydrophobic or hydrophilic). The surface morphology and the chemical changes on the materials are studied using Scanning Electron Microscope (SEM), Fourier Transformation InfraRed Spectroscopy (FTIR) and Reflection InfraRed spectroscopy (RIR). The wettability and the stability (as a function of time) of the modified surfaces are investigated through contact angle measurements.The use of biocompatible polymers in the field of bio-engineering is dominated by the surface properties of the device material. Much effort has been extended on modifying material surface properties, to control the bioactivity. While polymers are important materials in industry and research, their applications are limited by poor adhesion and wettability. This paper focuses on modifying the surface properties of the polymers namely polyimide and silicone by using diode-pumped solid-state laser through Laser Modification-Direct Writing (LaM-DW) technique, for the application in electrodes of cochlear implants (CI). In case of cochlear implants the interaction to the cells of the connecting tissue is important. After implantation of the CI electrode, due to the growth of the connected tissue the electrical stimulation signal becomes unspecific. The aim is to develop an implant surface which improves the adhesion property between the electrode interface and the connected tissue, and at the same time reduces...