Fully Batch Fabricated Magnetic Microactuators Using A Two Layer Liga Process

Full batch fabrication and successful testing of electromagnetic linear actuators is demonstrated. The fabrication uses a 5 mask process that combines two deep x-ray lithography layers and 3 optical lithography layers. Material magnetic properties have been investigated and the relative permeability of nickel was found to be 12 while that of nickel/iron permalloy was 400. Design rules are derived for the case of a microrelay where large forces at small gaps are required. Switching of relays was observed at 1.4 A for a relay made out of nickel and at 45 mA for one of permalloy. Particularly for permalloy, the contact forces at 1A are well beyond those of miniaturised relays.