Piezoelectric-Based Hybrid Reserve Power Sources for Munitions

Reserve power sources are used extensively in munitions and other devices such as emergency devices or remote sensors that have to be powered only once and for a relatively short duration. Current chemical reserve power sources, including thermal batteries and liquid reserve batteries require sometimes in excess of 100 msec to become fully activated. In many applications, however, electrical energy is required in a few msec following the launch event. In such applications, other power sources have to be provided to provide power until the reserve battery is fully activated. The amount of electrical energy that is required by most munitions before chemical reserve batteries are fully activated is generally small and can be provided by properly designed piezoelectric-based energy harvesting devices. In this paper the development of a hybrid reserve power source obtained by the integration of a piezoelectric-based energy harvesting device with a reserve battery that can provide power almost instantaneously upon munitions firing or other similar events is being reported. A review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices and their charge collection electronics for use in the developed hybrid power sources is also provided together with the results of testing of the piezoelectric component of the power source and its electronic safety and charge collection electronics.