SLIGA Based underwater weapon safety and arming system

Abstract

The Naval Surface Warfare Center, Indian Head Division (NSWCIHD) is applying microelectromechanical system (MEMS) technology to underwater weapon Safety and Arming (S&A) system development. MEMS technology provides an opportunity to develop a miniaturized S&A system that is more sophisticated with improved safety and reliability at a lower cost compared to current systems. An S&A system prevents premature initiation of the weapon while reliably ensuring initiation at the appropriate time. An S&A system uses multiple sensors and devices. In comparison with other weapon S&A systems, a critical aspect of underwater weapon S&A systems is the mechanical interlock system utilizing actuators and mechanical sensors. This paper describes the design, development and fabrication of S&A SLIGA device prototypes and of a SLIGA based S&A system. NSWCIHD worked with members of the HI-MEMS Alliance during design, development and fabrication. Advancements achieved by the HI-MEMS Alliance and SLIGA S&A design issues are discussed.

Moving reflector type micro optical switch for high-power transfer in a MEMS-based safety and arming system

“…The overall efficiency measurements include all optical losses (misalignment, Fresnel reflections and sidewall reflectivity). The reflectivity of the etched sidewall reflector is then calculated using equation (1).…”

“…The purpose of the S&A system is to prevent unintended detonation of a weapon while ensuring that detonation will reliably take place when needed. The first generation of the MEMS S&A device used LIGA processing to create a movable barrier that physically interrupted an explosive train initiator [1].…”

Systems that span nano-to-millimeter size scales

“…We have chosen for our case study the development of a Safety & Arming (S&A)/Fuzing device that can be used in undersea weaponry, an effort being led by the Naval Surface Warfare Center, Indian Head Division [5]. An ONR/DARPA funded technology program commenced in 1994 as an investigation into adapting microelectromechanical technology for use in the development of next generation undersea weapon systems and into evaluating the potential of applying such a system across the entire spectrum of Navy weapon systems.…”

“…• Hydrostat -consists of a bulk micromachined diaphragm, which actuates a LIGA lock on the slider interrupter via a direct mechanical coupling [5]; • G-sensor -mechanically coupled to the slider interrupter to serve as a lock;…”

High-power optical microswitch based on direct fiber actuation

“…Finally, an important and unique feature of the present work is the demonstration of high-power optical switching through coupled multimode fibers with losses well below 1 dB. Specifically, the device was designed for optical power transfer in a MEMS based safety and arming system (S&A) for underwater weapons applications [17,18], in which a 1 × 1 switch configuration is used to transfer optical power between input and output fibers in the on state, with no power transferred in the off state. A previous reflector-based optical microswitch designed for this application [18] exhibited an average optical efficiency of only 55% (2.6 dB loss) due to light scattering introduced by reflector surface roughness.…”