Microscale resin-bonded permanent magnets for magnetic micro-electro-mechanical systems applications

A micromachining technique has been developed for the fabrication of microscale resin-bonded permanent magnets. Magnetic paste has been prepared from Sr-ferrite powder and an epoxy resin, filled into lithographically defined molds, and formed into resin-bonded magnets after room temperature curing. Coercivity of 356 kA/m (4480 Oe), retentivity of 33 mT (330 G), and energy density of 2.7 kJ/m(3) have been achieved in 65-mum-thick disk arrays with lateral dimensions ranging from 50 to 200 mum. Based on the developed magnet, a magnetic MEMS actuator has been designed, fabricated, and characterized. Actuation current up to +/-60 mA operated the actuator up to 70 mum in attractive and repulsive motion. This work can be used for producing thick-film type permanent magnets, which can be scaled from a few tens of micrometers to millimeters on various substrates. (C) 2003 American Institute of Physics.