Abstract:

The emerging development of energy harvesting products has helped to reduce the cost of ownership of micro-power applications such as wireless sensor networks, providing potentially maintenance free-power sources, and can provide power to wireless nodes using energy present in the environment surrounding the application. Issues arise, however, with conventional energy storage devices such as batteries and capacitors, when they are required to provide reliable uninterrupted service to these applications for periods in excess of ten years. These issues include inherent high self-discharge rate and relatively short life spans, and prevent use of harvested energy to power consumer, industrial and civil applications. Additionally, the continued development of applications where energy harvesting is the primary power source in place of traditional battery or infrastructure energy sources is creating a demand for easily integrated, efficient "Plug and Play" modules that both store input energy and provide a regulated output for the target application electronics.

The combination of new thin-film Micro-Energy Cells (MEC TM) and efficient energy management electronics available from Infinite Power Solutions provides an energy storage solution that can last the lifetime of the target application, has the lowest energy loss, and the most efficient storage solution available using energy harvested from the environment surrounding the application. This new Micro Power Module (MPM TM) exploits a wide range of energy sources including solar, vibration, thermal and RF, directly accepting and storing inputs from energy harvesting devices and producing direct current through radio frequency energy, from 1 microwatt through 150 milliwatts continuously. An output regulator provides various regulated voltage options at continuous power levels exceeding 200 milliwatts.

Since many typical energy harvesting devices nominally produce energy at power levels below 100 microwatts, efficient gathering of that energy can be difficult using traditional regulation and conversion methods. The unique properties of the MEC that is in the MPM eliminate the need for regulation at typical EH power levels. Moreover, the low input energy threshold allows the MEC to efficiently accept power at levels as low as 1 microwatt and then store it for periods in excess of 10 years, ready for use on demand by the connected application via the integrated output regulator.

The MPM can be easily integrated or designed into existing or new applications without the need for external regulation or conditioning circuitry on either the EH inputs or at the regulated output. Options available include development tools, surface mountable versions, and reference designs available under license - all intended to provide rapid integration of energy harvesting into applications that need an autonomous energy supply.