| Despite their constant evolution over the last few decades, wireless communication networks still struggle with energy conservation. The problem manifests itself in many applications, in particular wireless sensor networks, where communications do not occur frequently and nodes often remain idle, and also small-scale communication networks, whose nodes need to be minuscule. Such applications can achieve optimal energy-efficiency using passive (battery-less) receivers that wirelessly receive energy and information at the same time. In this thesis, we present techniques to simultaneously deliver energy alongside information during wireless communications.;First, we present mechanisms to consolidate energy and information transfer in wireless sensor networks. We introduce iPoint, a communication system including a passively-powered wireless receiver capable of establishing two-way communication with a commodity smartphone. In contrast to traditional RFID tags, iPoint provides high computation and sensing capabilities and most importantly does not require specialized reader device to communicate. We prototype and experimentally evaluate our design that includes optimization techniques to ensure efficient delivery of energy and information and novel communication protocols.;In the second part of our work, we study energy and information transfer at small scale, particularly in biological systems. We introduce Bio-enabled Wireless Networks (BWN); these theoretical networks feature wireless communication between wireless nodes and tiny biological organisms. We introduce possible designs for such networks using several enabling technologies, and present theoretical results on the performance of energy and information transfer. In particular, we conduct a theoretical analysis to investigate the efficiency of wireless energy transfer to an electromagnetically-coupled nanoresonator, a potential building block for future BWNs. |
