Design of microelectromagnets for magnetic particles manipulation

The design of a ring trap for the confinement of magnetic microparticles based on thin-film technology is proposed. The study is conducted with a commercial electromagnetic software, using design specifications obtained from a preliminary analytical and technological study. A two-ring trap system is optimized to obtain the required magnetic flux density able to trap the magnetic microparticles while satisfying the heating constraints. In particular, the temperature in the area where the particles are collected is kept below 37 degrees C, in order to prevent thermal effects on the particles, allowing their manipulation without bud formation, fragmentation, and hemolysis. The resulting configuration represents a viable solution for the fabrication of microanalytical devices featuring on-chip ring traps without the need of external active cooling systems.