Question: what do you do with a “wirelessly” re-charged electric toothbrush when its battery eventually dies?
Answer: salvage the tiny induction coil from inside the sealed body of the toothbrush handle. It’s ideal for making your own pickups. All it needs is a magnetic core and some patient, fine wiring work.
I glued a stack of a few 12mm diameter molybdenum magnets inside the coil’s bobbin, using a quick-setting epoxy resin. The results from a single coil pickup were so pleasing that I added a second, arranging the opposing magnetic senses and observing the required electrical polarities in order to make a mini-humbucker. I marked the magnets and the wires with red and black Sharpie pens to keep the assembly on track. The hardest part for me was stopping the fierce wee magnets from clumping together, so I used small clamps and glued them to a baseplate at two different times.
There are plenty more detailed photos in this shared Google Photos album of mine which might inspire you build your own version: