Wireless power transfer in a body-centric setup: Recent advances and remaining challenges

In the recent past, wireless power transfer (WPT) has attracted a lot of research interest as enabling technology for wireless sensors networks, within the context of the Internet of Things, and to finally achieve fully autonomous electronic devices. A setup where wirelessly powered electronic devices are deployed on the human body is both very appealing and very challenging. Indeed, autonomous sensors that are unobtrusively integrated into the wearer´s jacket may monitor body parameters and the user´s environment while remaining invisible to the mobile user as well as to other persons in his/her proximity. Unfortunately, the body-centric environment is one of the hardest configurations to implement such a wireless transfer, given the movement of the wearers and the potential health hazards associated to the exposure to radiofrequency (RF) fields.