The Future of Silicon Nitride: Biomedical Applications and Beyond

This closing chapter highlights silicon nitride’s continued development, clinical translation, and industrial adoption (Si3N4). The surface chemistry of Si3N4, addressed in earlier chapters makes it truly “a bioceramic with a gift” that has a positive impact on mammalian cells and a negative impact on pathogens such as bacteria, fungi, and viruses. While the adoption of Si3N4 into biomedical implants is still early, the material is attracting attention for its unique combination of biocompatibility, osteoconductivity, and antibacterial properties. Going further, Si3N4’s hardness and wear resistance make it suitable for implants that replace diseased hip, knee, and shoulder joints, as well as high-performance surgical instruments such as dental drills. In these applications, Si3N4’s high-fracture toughness, strength, hardness, wear resistance, and low-friction coefficient are ideal. Si3N4 is friendly toward all radiographic imaging modalities, with minimal to no image distortion, facilitating accurate placement and monitoring of implants. Si3N4’s antipathogenic properties will likely find application in wound dressings, antimicrobial filters that decrease viral propagation, antifungal agents, antimicrobial surfaces in public-use places, and antimicrobial fabrics for surgical gowns, masks, and drapes. Preliminary research has already set forth the foundation for these antimicrobial applications. Future Si3N4 applications will also likely address brain-computer interfaces, neural prosthetics, and bone replacements in neurosurgery. Biodegradable Si3N4 particles could target drug delivery to remote anatomic sites. Beyond healthcare, Si3N4 is already used widely in industrial and aerospace applications, and will likely have future uses in quantum computing, and beyond. Hopefully, this closing chapter will encourage collaboration across research, engineering, and technical teams to come up with rewarding discoveries and scientific achievements.