PCB coil electromagnet
Budget: $10 – $30 USD
I need a pcb coil electromagnet designed similar to Carl Bugeja's Flexar pcb actuators (you can find them on his YouTube channel), but I need mine to be about 8 cm in outer diameter and it needs to be powered off of 3.3/5 volts and must produce a magnetic field strong enough to move ferrofluid in a display.