Numerical simulation and test of a UV-LIGA-fabricated electromagnetic micro-relay for power applications

The research work presented in this paper focused on the modeling, simulation, and test of the dynamic performances of a UV-LIGA-fabricated electromagnetic power relay. The relay consists of a microfabricated magnetic core, a spring-suspended Ni-Fe plunger, and a mechanically wound solenoid. The performances of the prototype relay are consistent with those predicted using mathematical models. The current capacity of the prototype relay with a plunger thickness of 17 μm was measured to be over 300 mA. Switching currents over 100 mA have been applied to the electromagnetic without overheat related failure. The maximum square wave frequency tested for the prototype relay was measured as 500 Hz. The flexibility of the design and the UV-LIGA fabrication technology used make the scale-up of the power capacity possible if needed. The current capacity of the relay may be further boasted by optimal design of the suspension spring and the magnetic core that serve as part of the electrical circuit. The moderate current capacity was the result of the manual assembly, and can be improved with wire-bonding technology and adoption of coils from commercial vendors.