How does PET sound? I also was thinking and doing a little more research but maybe we could friction or laser weld HDPE around a gold plated N52 magnet. We should be able to keep the magnet from gaining too much of that heat and demagnetizing. I also see a problem with the half life of HDPE but a sufficient coating would still have it last for decades. Thereās a guy on biohack.me that made a small batch of PET and HDPE magnets that seemed to have some decent success. Hereās the link if anyone wants to go read his posts about it, heās got a few thermoplastic coated magnet projects that had some promise: https://forum.biohack.me/index.php?p=/profile/discussions/dieselpwr
I used to laser weld little capsules (about 4x15mm) with magnets inside.
We stacked a spacer and 3 magnets on top (one sided needed to be magnetized but not the other), then put a cap and weld that cap on the casing. I had our machine shop make a stainless ācolletā to act as a heatsink and never had overheat issue (the magnets were Magnetized before we got them). Barely need any polish and out canāt find the weld wi
Also done titanium, but never the little magnet floater ā¦
Would that be a viable option for implants?
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Unfortunately PET will not survive in the body that long. Lasers and HDPE / polymers donāt weld wellā¦ charring and off gassing from the process create concerns about integrity and material contamination.
Capsules of what? Ptfe or?
Sanitary stainless capsules in a clean room environment.
They were going into sensors and meters used in the semiconductor industry. They had to be absolutely hermetic, handle hight temperature and high pressure and have high polish outside to no pickup anything during the deposition process ā¦
Iām happy to answer any questions you have on āexoticā welding processes 
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What were the wall thicknesses you were dealing with?
Were you machining the capsules or purchasing them from a supplier?
What was inside the capsules?
What type of laser were you using? Chemistry?
What was the power output of the laser?
Was there a guy named Gary anywhere in the facility?
What is the significance of Brocaās area?
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The walls were about 0.5mm
Capsule size about 4x15
Material 316L and other property stainless.
They were manufactured to our spec.
We machined a few in emergency, but we didnāt quite have the tooling for mass production (we used to weld them in batches of 100 to 500 pieces ā¦)
A stainless spacer and 3 to 5 dot magnet (depending on model) the dots magnet were ~3x1mm
Once welded everything had to be airtight and not moving, rattling was an automatic reject.
Fiber laser with 4 axis CNC and enclosed chamber filled with argon. The laser itself is about the size of a car, the enclosed chamber and CNC system is the size of small CNC machining center + computer tower and shielding gas system
From memory it topped off around 2Kj but I ran it around 100/120j ā¦ From memory 
No idea what youāre talking about
Sorry for the long response
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What were these used for? So curious.
They were used as the floating element for flow switch/sensor for vapor deposition equipment for the semi conductor industry. Most of it went into the vapor deposition equipment.
We also did all the valves and regulator for them ā¦
The crazy things is that all of it is basically single use ā¦ when the pickup chambers are umpty, they throw everything away and install all new regs/valves and sensor to avoid cross contamination.
One wonders why some of these processes are so expensive
Because the machines are so expensive ā¦ The laser was about $3/4M installed for a slightly used unit noone have them. So the few shop that have them can charge as much as they want ā¦
Ps: programming them takes extremely long ā¦ New material on the little capsules took me about 10+ hours and 100+ test run to get them right. Once itās all going smooth itās 60 to 80 per hour production speed ā¦
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Is ultrasonic welding viable? Could we take two halves and ultrasonically weld them together? A lot of polymers have no problem ultrasonic welding to each other. We could maybe avoid the Curie limit problem.
Yep I looked into itā¦ should totally work but the horn design and whole apparatus is expensiveā¦ if anyone has an ultrasound welder I could send some polymer samples for testing
Oh actually I remember now why it probably wonāt workā¦ To be viable for implants you have to remove air molecules from the equation so you need to weld in a really damn good vacuumā¦ difficult. Otherwise the chains wonāt bond well and youāll get infiltration.
Difficult, but not impossible 
Damn, during the pandemic I worked with ultrasonic welders. Had a bunch of them just laying around the shop. I shouldāve taken some home when they laid me off the weekend before Christmas lol
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Came across this ā¦ would their low temp sanitization be enough for implantation?
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Yep. Itās what we use in the labā¦ otherwise called gas plasma.
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That is super interesting to watchā¦ But there are a lot of little details of course that were left out.
The magnetization process is extremely violent and generally speaking you can only magnetize a neodymium core a couple timesā¦ maybe three timesā¦ after that it will tend to shatter because of the internal forces of the magnetizing pulse.
It is also possible to accidentally heat it to the point where it is unrecoverable, but again this usually physically disassembles the magnetic core as well so it is fairly obvious it canāt be re magnetized again in its original form.
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