Abstract
Traditional battery-powered wireless sensor networks face many challenges to meet the requirements of a wide range of demanding applications nowadays due to their limited energy. Although energy harvesting techniques can scavenge energy from the environment to sustain network operations, dynamics from the energy sources may lead to service interruption or performance degradation when the sources are unavailable. Recent advances in wireless energy transfer have opened up a new dimension to resolve the network lifetime problem. In this paper, we present an overview of the wireless energy transfer techniques and recent developments to apply these techniques in various sensing applications. We also show how this novel technology can be integrated with classic data collection applications and envision future directions in this area.