NdFeB magnets have long played an important role in the medical industry, including their use in the interior and exterior of the body, motors and sensors for medical devices, and have a wide range of uses in the medical industry, as advanced as the innovations related to the technologies being studied today. While every application is unique, valuable insight and collaboration are required from the design and development phase all the way through production to get the best end product.
Product Application and Confidentiality
Most medical customers start with an idea or concept that they expect will be patented at some point and guarantee a mutual confidentiality agreement when they start discussing the magnetics part. Respect and protect the intellectual property (IP) of our customers and understand that the incubation period of new products can take a long time, with many changes occurring along the way and constantly collecting data. This can be a challenge for the end application, where the requirements for magnet or magnetic components require proper simulation and optimized design before the first prototype is manufactured. Although simulation and optimization are close to the results of the final design, the actual design work of prototyping and testing and verification is still indispensable.
Magnets Used in the Body
Magnets used in the body goes far beyond the requirements of "conventional" magnet applications, biocompatible for coatings on contact medical magnets, and approved coatings for magnets include gold, palylene, titanium or rhodium. The right coating can help improve corrosion resistance to certain chemicals and is also safe for internal use. Polyethylene terephthalate on magnets has long been associated with medical and technical applications, providing a durable, corrosion-resistant coating that can be used in Parylene C, D and N.
Magnets in environments where they hit or hit or grind other parts may cause scratches and chips in the coating, causing oxidation. In some applications, doubling the coating thickness may help, but tolerances need to be checked to ensure that additional thickness can be used. Gold is an FDA-approved medical coating for use in the body, it has a nickel-copper-nickel base coating, standard gold plating thickness: 0.3-0.6 microns, and the maximum operating temperature is about 200 °C.
Almost all magnets used in the body are small and neodymium is almost always used due to the need for stronger magnets, and sometimes, an application environment is found that tries to challenge the laws of physics or requires magnets to perform tasks beyond their capabilities. For example, a tiny 0.5mm x 1mm cylindrical magnet provides 20 pounds of holding force, or a sensor reads 4000 gauss from a 1mm x 1mm disk at a distance of 3 inches. For magnets, it is important to understand the possibilities available in the dimensional requirements, acceptable tolerances (note: try not to be too tight if possible), and the desired results.
Magnet shape often depends on the application and result requirements, most magnets used inside the body tend to be small cylindrical, while magnets used outside the body come in many shapes and sizes, and just as important as the shape is the direction or orientation of magnetization. For example, an application that passes a magnet through a sensor, the initial design shows that the magnet has axial magnetization, and once more is known about the sensor, one realizes that the magnetization direction should be radial. After the correction, the sensor and magnet work well as one component.
If the right magnet and coating are selected based on the temperature, cleanliness and chemicals to which it is exposed, the magnet will work indefinitely and continuously. Neodymium magnets come in many grades, so choosing the right grade to handle temperature requirements is a good starting point, and once the correct grade is determined, consider the requirements of the environment to which the magnet will be exposed. If the magnet is cleaned with common chemicals or placed in a sterilization equipment, then the coating that can withstand this environment will be very important, and it will be crucial that the magnet may encounter more areas than the ambient air.
Testing, data collection, more data collection, considerable time and effort required to go from concept to FDA-approved product, extensive list of documents and reports required for each batch of product. Understand what documents and tests are required during initial testing and production to get the right test procedures, manufacturing processes, and required document lists before mass production.
Conclusion
The above topics are just a starting point when considering the use of magnets in medical applications, and advances in medical technology and applications require the opportunity to work with the most innovative and creative minds in today's healthcare industry. Continue to challenge and push the boundaries of magnets, magnet assemblies, magnet circuits, and coatings, which involve short-term surgical use, long-term device placement, and precise use of sensors and precision motors.
