So if the chip is .1 mm and sufficiently metallic such that magnetic force of a neodymium magnet will cause the magnet to “stick” to you, then the following would be possible.
If you taped/fixed the (strong) magnet over the spot where the chip went it, it might, possibly, migrate its way up-out over time. You might be able to pull it out with the magnet just sitting there all the time.
If that worked, it might be a bit painful as it worked its way out.
.1 mm is not that big. This is the size of fine to medium grains of sand.
I also point out again the if you have a .1 mm chip in your arm, it should show up on a careful x-ray. Any of you dentists or other x-ray doctors out there, you could image the vaccination site.
These experiments would need to be done pronto because anything that small is going to “wander around” in the body and become more difficult to find later.
TSA will now ONLY let you fly IF you set off their metal detector.
Just think what even a 1mm metalic object could do with your innards in an MRI. It would whirl in circles like a tiny blender blade on liquify.