Apostolos Georgiadis, PhD, is Honorary Associate Professor at Heriot-Watt University, Edinburgh, UK. He is vice-Chair of EU COST Action IC1301 on Wireless Power Transfer for Sustainable Electronics. He is former Editor-in-Chief of Cambridge Wireless Power Transfer Journal and former Associate Editor of the IEEE Microwave Wireless Components Letters and IET Microwaves Antennas and Propagation journals. He is URSI Fellow, Chair of URSI Commission D Electronics and Photonics 2017-2020 and a former ADCOM Member and Distinguished Lecturer of IEEE Council on RFID (CRFID).
The presentation begins with an overview of energy considerations and challenges for low power system requirements in emerging applications such as health and smart homes, environmental monitoring, as well as an outlook of various energy harvesting technologies. The state-of-the-art in commonly used energy harvesting technologies such as solar, piezoelectric, thermal and electromagnetic is then presented. Figures of merit are provided and emphasis is placed on design challenges and novel technologies and materials, such as paper, textiles, inkjet printing.
Special focus is placed on hybrid–multiple technology harvesters leading to the development of low profile and conformal solar antennas and solar–electromagnetic harvesters. Design and optimization challenges are provided. Nonlinear circuit optimization combined with electromagnetic analysis is used to optimize circuit performance, and design methodologies for ultra-wideband and multiband RF energy harvesters are presented. Continued interest in electromagnetic energy harvesting is attributed to the minimum additional cost associated with its implementation due to existing antenna modules on wireless sensor nodes and RFIDs, as well as due to the capability for powering of wireless devices by intentional radiation known as wireless power transmission. The latter is addressed and novel system concepts such as transmission of chaotic signals for optimum performance are proposed. Circuit and system examples of autonomous system operation are demonstrated such as wirelessly powered sensors, beacon signal generators, energy harvesting applied to RFID systems. Finally, future perspectives and challenges are discussed in terms of energy storage, materials, and circuit performance and application scenarios.