Metal Brazing‐Free Ceramic‐to‐Ceramic Hermetic Sealing for All‐Ceramic Active Implantable Devices

ABSTRACT Hermetic sealing of engineering ceramic‐based active implantable medical devices (AIMDs) is a crucial part of their fabrication and significantly influences the reliability and lifetime of the devices once implanted within a biological environment. Since conventional hermetic sealing is often achieved by metal brazing or soldering via laser welding, it requires complex, time‐consuming prefabrication processes and contributes to artifactual distortions when the implant recipient undertakes medical imaging procedures like MRI. An alternative to metal brazing is glass sealant or fritted glass powder. However, due to the opaque properties of sintered ceramics such as alumina and zirconia, sealing using fritted glass powders positioned between the ceramic parts is challenging, as the laser is unable to pass through the ceramic to melt the casted glass frits. In this study, we propose a rapid process of laser‐assisted sealing of ceramics using an aqueous paste containing glass frits, cellulose, and graphene as a soldering material, which is cast onto the edges of ceramic‐to‐ceramic interfaces, and hermetically sealed using a welding laser with a custom‐built vertical motorized spinning stage. Our work provides a metal‐free encapsulation solution that is fast to implement and allows inductive links for wireless power transfer to operate more efficiently.