Design and implementation of a dynamic power management system for wireless sensor nodes

For wireless sensor nodes to be fully autonomous and to have long lifespan, there is the need to make them selfpowering. This requires that energy be harvested from ambient sources, such as vibration, light and heat, in order to supply the electrical power requirements. Thus, there will be no need to replace batteries that are currently used to power wireless sensor nodes. The long-term goal is to make wireless sensor nodes truly battery-free. However, the energy harvested from the indoor environment is not matched with the power requirement of wireless sensor nodes, as it is very small and random. In order to solve this problem, a middleware for the dynamic power management of a sensor node is proposed, the hardware structure of the middleware and the system operation flow are described, and the performance of the system is evaluated. It is shown that the proposed middleware is an effective way of solving the challenging problem of providing a sensor node with an extended lifespan.