There are many factors affecting the appropriateness of a magnet for implantation. The material a magnet is made of and its size, shape, and orientation determine the field and thus how effective it is at either producing sensation or lifting objects. Although
There are many factors affecting the appropriateness of a magnet for implantation. The material a magnet is made of and its size, shape, and orientation determine the field and thus how effective it is at either producing sensation or lifting objects. Although lifting objects is a fun way to demonstrate an implant the focus of this section will be on magnets optimal for sensation. Far more important than field though is getting a magnet coated with a bio-compatible material. A person can’t fell or lift with a magnet that rejects.
There are many materials used to make magnets but most are far too weak for our purpose. The most common and oldest type of manufactured magnets are Ferrite and Alnico. Most fridge magnets are made of Ferrite. The old horseshoe shaped magnets sold as children’s toys are made of Alnico. Both of these types get their magnetism from the alignment of the iron within. Although inexpensive and easy to work with these iron based magnets are nowhere near strong enough for our purposes. In terms of strength, iron based magnets have been superseded by rare earth magnets such as Samarium Cobalt (SmCo) and Neodymium Iron Boron (NdFeB). SmCo is very strong compared to Iron based magnets and has some desirable qualities such as the ability to withstand high temperatures. It’s strength though pales in comparison with NdFeB.
The strongest type of permanent magnet type is NdFeB. It’s the optimal choice for an implant. This shouldn’t be misunderstood as claiming that a more powerful field is always better. Some grinders have experimented with placing very large powerful magnets. Although these are obviously able to lift more, they are also strong enough to cause crush injury to the tissue between the magnet and whatever is being lifted. The reason NdFeB is optimal is that allows for a smaller magnet size; this in turn allows for a smaller and thinner implant which is less invasive, less likely to be rejected, and produces better results in terms of sensing the electromagnetic spectrum.
Amongst NdFeB magnets, there is a spectrum of grades available. The higher the grade, the stronger the magnet. The grade is determined by the number which follows the indicator “N.” This N number is the maximum energy product of the magnet using the unit Mega Gauss Oersted. This N scale is linear so an N42 would be twice as strong as an N21 grade magnet. The highest grade of NdFeB magnet commercially available is an N52.11.The strength of these N52 grade magnets is phenomenal. Consider that a four inch square with a depth of.5 inches can suspend over 300 pounds.
There are only two shapes commonly chosen for implants: discs and cylinders. Because these implants function by displacement of the densely innervated fingertips, hands, and less often tragi, discs are the most common. A disc shape can be seated unobtrusively and yet provides a broad area of displacement in response to nearby fields. Cylinders are becoming more popular and have promise in terms of providing an easy means of implantation. An appropriately sized model can be implanted with use of an RFID injector. Many people are intimidated by the idea of opening up and undermining their own flesh. The injection method would be undeniably simpler. As of this time, there are no injectable magnets being sold prepackaged and sterilized but both Dangerous Things and Cyberise are working to make this a reality.
A cylinder implant comes with a significant downside. The field shape produced is less desirable and the total field strength is significantly reduced. One way to demonstrate this is by comparing the pull forces in relation to a magnets volume. 2x12mm Cylinder has a volume of 38 cubic mm and a pull force of 0.46 lb whereas a 1x3mm Disc has a volume of 7 cubic mm, and a pull force of.30 lb. The cylinder magnet has more than 5 times the volume of the disc but only provides just over a 50% increase to pull force. This doesn’t mean that cylinder magnets aren’t worth considering. The ability of a shape or design to elicit the maximum sensitivity to the electromagnetic might not end up being determined by any of these characteristics at all. I’ve spoken with a number of grinders that self-inserted cylinder shaped magnets that report contentment with their implants.
There are a number of ways that magnet shape could be improved in future models. For example, a disc magnet produces symmetrical field lines resulting in about half of the magnetic field being directed deep to the implant rather than aimed at the surface. Arc magnets like the ones used in brushless motors produce a more desirable asymmetrical field. The problem with an arc shape is that it’s nearly the exact opposite of the contour of the body. The large outward facing arc creates a pocket which the body would struggle to fill and two pressure ridges that will inevitably break down skin. Sphere shaped magnets are an interesting shape in that they produce a symmetrical field but have particularly focused flux near each pole. Similar issues exist however in terms of using a sphere for an implant. A sphere under the skin produces a very undesirable pressure point.
A particularly promising shape is that of a parabaloid. This shape is commonly used to project or collect different forms of electromagnetic energy. For example, a satellite dish collects signals from a broad area and reflects it upon a small receiver positioned directly at the dish’s focal point. A paraboloid shaped magnet also projects its field towards a focus but has similar disadvantages as an arc magnet. Paraboloid magnets aren