Although silicon nitride was discovered over 150 years ago, it took more than a century for it to be recognized as a game-changing material for commercial and medical applications. This unique ceramic compound has recently become one of the world’s leading materials for creating next-generation medical devices, aerospace components, and thousands of other industrial parts. In this exclusive SiNAPTIC article, we’ll explore why silicon nitride is revolutionizing the production of medical devices and how inventors, manufacturers, and biotech companies are rapidly adopting it as the go-to material for their implants.
What is Silicon Nitride (Si₃N₄)?
Silicon nitride is an inorganic, non-metallic, odorless ceramic powder composed of silicon and nitrogen. Discovered in 1857, silicon nitride’s incredible properties were not fully recognized until the 1950s when a handful of British and US manufacturers began using it for specialized research and development. When its manufacturing costs dropped in the '70s, more scientists began discovering the usefulness of this compound for various technical product development efforts. Interestingly, silicon nitride’s first natural occurrence was discovered not on Earth but in tiny inclusions from deep-space meteorites in the 1990s.
Silicon nitride is prized for its resistance to abrasion, corrosion, and high temperatures, and, for medical devices, its fracture resistance, which exceeds that of all other advanced ceramics. When used in the creation of implants, silicon nitride possesses a hydrophilic, microtextured surface, making it a top choice compared to common PEEK or titanium alternatives.
Why Silicon Nitride is Important for Medical Devices
When it comes to medical devices, implants, and prosthetics, silicon nitride has two additional critical attributes: it is bioinert and exceptionally biocompatible, allowing the human body to more easily integrate parts made with it for long-term use. This is due to its superior osseointegrative and antibiofouling qualities, which help increase the success rate in various types of surgeries. Overall, silicon nitride boasts a variety of impressive mechanical characteristics, making it the optimal choice for producing medical devices of all kinds, especially in orthopedics, spine, dental, and other medical areas. Some of its most common applications include spinal fusion surgeries, articulating devices such as knee and hip endo-prostheses, and even bone graft replacements.
Beyond its health-related benefits, another major reason medical technology companies are reengineering key medical devices with silicon nitride is that advancements in technical ceramic printing dramatically increase the speed at which new options are brought to market. By skipping the costly and time-consuming tooling procedure, new scientific knowledge enables device makers to rapidly prototype and scale production like never before. While strength and biocompatibility are top priorities for many medical device makers, recent breakthroughs in electrochemical anodization, vapor deposition, and ionized blasting have greatly improved the surface characteristics of silicon nitride medical devices, reducing the body’s natural risk of implant rejection.
How is Silicon Nitride Used to Make Medical Devices?
Medical implants using silicon nitride are most commonly made through LIS (laser-induced slip casting) or a related but distinct process called LCM (lithographic ceramic manufacturing), depending on the exact requirements of each device. Each part starts as a wet slurry that is carefully formed into the desired architecture using cutting-edge technical ceramic printers. In general, LIS is best suited for thicker, larger parts with full densities, whereas LCM is frequently used to create complex microstructures that require the high resolutions needed for most medical devices. Starting with a CAD model, LCM printing uses state-of-the-art laser-driven technology beneath a small vat of silicon nitride slurry, printing each part from the bottom up to ensure near-perfect tolerances and accurate reproducibility.
Once the initial print is completed, the devices remain extremely fragile but gain their strength through a technique called debinding and sintering. This occurs during a process called thermal processing, where the parts are placed into ultra-high-temperature furnaces that can exceed 3,100°F, removing the binding agents and solidifying the silicon nitride into its optimal, highly rigid form. Afterward, each part is sintered to complete its strengthening, then undergoes final polishing or glazing depending on the desired aesthetic or necessary application. The parts are then cleaned and packaged for use in hospitals worldwide. This entire process takes between 1 to 3 days depending on the size, complexity, and quantity of the medical devices.
What Medical Device Manufacturers Can Do to Start Leveraging Silicon Nitride
If you are considering implementing silicon nitride in new medical device development or looking to improve an existing product line of implants, here are a few things you should know first.
#1: You can easily outsource prototyping and production.
While there are several factors to consider when deciding whether to outsource silicon nitride device production or invest in in-house capabilities, you can mitigate initial risks by working with a qualified laboratory like SiNAPTIC. We have a fleet of Lithoz’s best LCM technical ceramic printers, enabling your business to go from prototyping to finished product and even full-scale production without installing a single piece of equipment.
#2: 3D printed silicon nitride devices are ideal when speed to market is critical.
In the hyper-competitive world of medical devices and implants, traditional product development typically takes years from concepting and prototyping to ramping up manufacturing once demand is established. With 3D printed silicon nitride, you can significantly cut that time since no costly tooling is required, and design changes are as simple as adjusting your CAD files. This allows you to iterate faster to achieve a final output with less capital.
#3: Silicon nitride offers innovative properties not available in alloy or polymer-based devices
Doctors who see higher patient success rates with quality medical devices in their surgeries are often more likely to recommend them to their colleagues. Since silicon nitride offers a range of groundbreaking benefits to patients that traditional alloy and plastic products do not, it is becoming sought after by hospitals everywhere. This means your company can offer products that are not only new and improved but also poised to become the industry standard in the years to come.
If you’re looking to revolutionize your medical device production efforts, we offer comprehensive solutions for companies and inventors of all sizes, from start to finish. To learn more, book a consultation and get a quote from one of our silicon nitride technical ceramic experts today.