A micromachining technique is presented for the fabrication of resin-bonded permanent magnets in the microscale.Magnetic paste is prepared from NdFeB powder and an epoxy resin,filled into lithographically defined photoresist molds or metal molds,and formed into resin-bonded magnets after curing at room temperature.A coercivity of 772.4 kA/m,a remanence of 0.27 T,and a maximum energy product of 22.6 kJ/m3 have been achieved in an NdFeB disk micromagnet with dimensions of Ф200 μm×70 μm.Based on the developed micro-patterning of resin-bonded magnets,a fully integrated electromagnetic vibration energy harvester has been designed and fabricated.The dimensions of the energy harvester are only 4.5 mm×4.5 mm×1.0 mm,and those of the micromagnet are 1.5 mm×1.5 mm×0.2 mm.This microfabrication technique can be used for producing permanent magnets tens or hundreds of micrometers in size for use in various magnetic devices.
