Ambient RF Energy Harvesting From a Two-Way Talk Radio for Flexible Wearable Wireless Sensor Devices Utilizing Inkjet Printing Technologies

• Published in: IEEE transactions on microwave theory and techniques Vol. 63; no. 12; pp. 4533 - 4543
• Main Authors: Jo Bito, Hester, Jimmy G., Tentzeris, Manos M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-12-2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Autonomous sensors; Energy harvesting; Fabrication; flexible; Ink; Ink jet printers; inkjet printing; on-body; Power measurement; Printing; Radio frequency; Substrates; wearable
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2015.2495289

A complete design and additive fabrication process of flexible wearable radio-frequency (RF) energy harvesters for off-the-shelf 2 W two-way talk radios utilizing inkjet printing technology is discussed in this paper. As a result of numerous output dc power measurements of fabricated proof-of-concept prototypes, a maximum output power of 146.9 mW and 43.2 mW was achieved with an H-field and E-field harvester, respectively. Also, the effect of misalignment between receiver and hand-held radio on harvesting performance is discussed in detail. To verify their potential in real-world wearable autonomous RF modules, the operation of E- and H-field energy harvesters was verified by utilizing an LED and a microcontroller communication module under on-body and on-bottle conditions, and the effect of the energy harvesters on the performance of the harvested communication systems was inspected through received power measurements in an anechoic chamber.