Effect of metal foil size on the actuation properties of micro-chip exploding foil initiator

Abstract

Exploding foil initiator (EFI)is a special kind of actuator that is used to drive the flyer. To realize high-velocity flyer output and low-energy firing, the size of bridge foil and corresponding structures of EFI were studied. Four kinds of micro-chip exploding foil initiators (McEFI) with different bridge foil sizes were prepared in batches using Micro-Electro-Mechanical System technology. Furthermore, the primary characteristics of the four kinds of bridge foils were comparatively performed and discussed, including the electro-thermal simulation, electrical-explosion properties, and flyer velocities capabilities. Most importantly, the velocities of the ParyleneC (PC) flyer were measured by photonic doppler velocimetry, indicating the PC flyer had better velocity capabilities with the reduction of the size of the bridge foil. The firing property of McEFI was validated by initiating HNS-IV pellets, and the critical threshold energy was determined as 0.22 μF/1095 V based on the sensitivity test. This structural change truly implements the popularization of the high-velocity flyer actuator or initiator.