The biggest issue Iāve run into is manufacturing. A one-off are different from being able to mass produce for a price that makes sense. I feel like specialized production processes arenāt likely to have a high yield at low enough cost that distribution is possible.
Every method attempted ultimately cost a ton to try out. I think in total, over the years, Iāve spent upwards of $50k to sort out a thin coating on sensing magnets that is robust and biosafe.
Steve Hawthornās magnets. How do they hold up?
I have someone in my dorm thatās had one for 2+ years now and his is still holding strong. Im considering one for myself if others can confirm they hold upā¦
He basically was tinkering with silicone coatings since about the same time I was playing with RFID implantsā¦ I think since around 2005. For many years they failedā¦ a lotā¦ but I hear from people that failures are more rare these days. What I can tell you though is that only a few years ago I did an analysis on a couple of his mags. I talk about some of that analysis in my āboo hoo no more magsā video;
In short, the material is not robust. It requires a lot of thickness to do itās job well enough but still there is wear due to itās plyability and the fact it doesnāt stick to the magnetās surfaceā¦ it just swims around inside the silicone. To be fair, nothing really sticks well to the magnets, not even resinsā¦ but anywayā¦ the other thing about silicone and how you manufacture such things is that it must be ripped out from molds which leaves the surface all fucked up and ripe for bacterial growth etc.
In general I just donāt like the thickness, the wear, and the surface quality of silicone encased magnets.
This is probably a good opportunity to clear up some misconceptions about how these magnets are made. The materials science is fascinating, and ranks up there with the lithium ion battery and the blue LED as one of the most influential scientific advancements of the last 40 years. The manufacturing process for sintered Neodymium magnets goes like this:
NdFeB alloy ingots are produced and then pulverized in an inert gas environment
Powdered NdFeB is compacted in the presence of a weak magnetic field to align the natural magnetic domains of the material. This means the physical structure of the magnet core is permanently aligned to be magnetic in one axis
The magnet core is sintered in an oven to fuse the powder together
Machining to achieve the various shapes and sizes
Coating is applied. The most common is electrolytic nickel, there are many options.
Now the cores are ready for their final magnetization, which is called āchargingā. Usually a large air-core solenoid is used with very high current to induce a field in excess of 1 Tesla. This device is very similar to a rail gun, so the charging process can be very stressful to the magnet and itās coating, creating micro cracks and faults.
Then, after some QC, theyāre ready to ship them out. Itās important to note that there is really two āmagnetizationā steps. One is matter (aligning domains) and one is energy (aligning electron spins). When you heat a Neodymium magnet above 100Ā°C, the electrons start to receive energy and move more erratically in their orbitals. As the temperature rises, the electron spins are shaken out of alignment more and more until you reach the magnetās Curie temperature at 320Ā°C. At this point it loses its magnetic field strength. You can hypothetically āre-chargeā the magnet in a magnetizer after this has occurred. Youāll recover most of the field strength that was lost, but you wonāt get it all back because of physical changes to the structure. Also, remagnetizing puts an already compromised magnet through all the mechanical stresses a second time, and they often fall apart.
Speaking in hypotheticalās, what are the chances/possibilities of acquiring magnets after step 4, and replacing step 5 with TiN or some other bio-safe coating before it gets magnetised?
Iām assuming its nowhere near that simple or else it likely would have been done before, but do you have any info on what the problems associated with it are?
So one issue is that the raw NdFeB core is extremely susceptible to oxidation, even after sintering, so acquiring the blanks would be a waste of your time.
What is usually done with the TiN coated magnets is that the Nickel coating (actually usually you would splurge for a Ni-Cu-Ni coating for redundancy) is applied to the core, and then the uncharged magnet is placed in a physical vapor deposition machine and exposed to a plasma stream which contains vaporized TiN powder and it is deposited onto the existing nickel coating. Then the Ni-Cu-Ni-TiN coated magnet is magnetized, which puts a huge strain on the ultra-thin TiN outer coating and creates micro-cracks through which your body can infiltrate and get to the reactive nickel underneath. Some people have tried also putting PMMA (which flakes) on top of the TiN, or maybe they tried some parylene, or maybe they tried some thermoplastics. They all seem to fail after a few months or years, and the yield is always low
Define ālow enoughā: are you sure thereās no market for implants with a very high price?
Tell you what: Iām not interested in sensing magnets personally. But if I was, Iām gladly pay north of 500 bucks for a low-risk implant with a high degree of confidence re long-term biocompatibility. I have the means to afford it, and I value my health more than a few cecils.
Assuming that would be the sort of retail price that would cover low-volume specialized manufacturing costs and your markup, maybe Iām not the only one out there with too much disposable.
I got it for sensing because there didnt seem to be a better option at the time and i couldnt get a definitive answer on whether it would work or not. so i figured id be the guinea pig. it works well for what i need it for, but nothing lower than your standard 120v circuits. Iām planning on replacing it with the titan when it comes in shortly.
So, in the possibility of being attacked for ressurrecting an old thread. Iāve been thinking about biomagnets a lot and, I donāt think we should be stopping R&D on magnets just because the TiTAN released. The TiTAN has the problem of being expensive and hard to manufacture. I donāt think thatās necessarily a problem as Iām willing to pay $600 in total for a sixth sense that will last theoretically forever but, that doesnāt mean I donāt think this forum can develop something that lasts a long time that has less mass, and is cheaper to produce. Iāve been putting a lot of thought and research into alternative coatings for magnets and, I think I have some ideas. HDPE seems like a great coating but it theoretically only lasts 30ish years unless it has a very thick coating. So I started looking into other materials such as PEEK. PEEK is a little expensive but much cheaper than machined titanium and can be deposited onto the surface of magnets in all sorts of ways. Thereās been a lot of research into biopolymers since this thread sorta died and I think R&D should never stop even if DT does have a pretty dope ass magnet atm. I mean letās give Amal a new product to sell to us all.
My understanding is that this has been done before to make very thin underlying layers before applying something else. What I wonder is why we canāt keep going with this process until thereās a sufficient coat of that alone. Too slow? Too uneven? Canāt build up multiple layers?
It seems like an issue with getting an even coating over the whole magnet and speed. Weād definitely need to design a process for this but it seems like you could directly coat a magnet in titanium like this. Then you just have a smaller TiTAN.
We donāt do that here zombie any thread, as long as itās relevant!
The problem with PEEK and PEAK is the forming temperatures are high, ruining magnetic material (curie limit).
Again, high tempsā¦ but also itās not a hermetic seal. The particles do not bond together well at the atomic level, they just mash together, but that does not keep water out and bodily fluids will eventually attack it. This is exactly what we tried with the m31ā¦ check the video about āDT isnāt doing magnets anymoreāā¦ I cover a lot in thereā¦ and rest assured I spent tens of thousands of dollars working on magnet designs and coatings that all failed.
Thatās not to say that more research shouldnāt be done. Titan is discontinued because of the expensive process to make it. Nearly all of the suppliers involved raised prices considerably to the point I couldnāt see making another batchā¦ so research needs to continue.
Definitely sad news. Was hoping to get one when I could afford it and the travel to Pineapple for the install.
Hopefully prices from the suppliers will go back down at some point and another batch could be made.