MEMS arm fire and safe and arm devices

Miniature arm fire and safe and arm devices include an electrically operated pyrotechnic initiation device (5) to generate a detonation wave upon command and a movable pressure barrier (9) that blocks propagation of the detonation wave if the device is not intended to be fired and opens a window (12) to transfer the detonation wave externally of the device. The detonation wave may in alternate embodiments be a subsonic flame front and pressure wave or a supersonic shock wave, respectively. An electromagnet (7) may serve to move the pressure barrier. Detonation waves output from the device have application in igniting an explosive train, either directly or indirectly, the latter by operating an electrical switch. In the arm fire device, the barrier automatically prevents a detonation output when electrical power is removed from the device. In the safe and arm device, the barrier, once moved out of the way, remains out of the way, even when electrical power is removed. Various forms of miniature single operate electrical switches are described that may be operated by the foregoing devices.