gms | German Medical Science

Objective: Biocompatible and long-term reliable packaging are essential for implantable device packaging. To reach the goal, various materials and processes are developed in many research. In this research, we propose new hybrid packaging technology that can secure as noted above characteristics for implantable devices especially in the sub-retinal stimulation system.

Materials and methods: Medical grade silicone elastomer, epoxy and parylene C were used as hybrid packaging materials. We developed single and hybrid coating process and improve process for better adhesion with different materials. Also each samples were evaluated light transmission, moisture permeability, biocompatibility and machine safety test in real and accelerated environments.

Results: In case of single coating, each materials show good biocompatibility (≥ 80% cell viability), light transmittance (≥ 80% at 550 nm) and moisture permeability (≤1.578417 g/m2∙day). In the results of hybrid coating, characteristic of light transmittance was lower but moisture permeability was improved by additional layer and biocompatibility was decided by the outermost material.

Discussion: In this study, we evaluate fundamental characteristics each coating process. To apply sub-retinal stimulation system, we need to develop customizing process for 4 parts (sensor and stimulator, cable, circuits and connecting). Also additional long-term reliability test by moisture permeability test in accelerated environment and implant test in animals are needed.

Acknowledgment: This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (Ministry of Science, ICT) (No. 2019M3A9E2030769).