As sensors are increasingly deployed in locations removed from mains power and increasingly expected to operate for times that are long compared to battery lifetimes we look to means for "harvesting" or "scavenging" energy from the sensors' operating environments. Whereas many sensors are "parametric" - their interaction with the environment causes a change in one or more of their electrical parameters - many other are true transducers - they perform their sensing function by extracting energy from their environment. These kinds of sensors can thus serve - under suitable operating conditions - both as measuring devices and as power supplies. In this paper we review this background, review the fundamental restrictions on our ability to extract energy from the environment, enumerate and summarize sensing principles that are promising candidates to double as power supplies, and provide several examples that span the range from already off-the-shelf at low cost to in laboratory prototype stage to sufficiently speculative that there might be reasonable doubt regarding whether they can actually work even in principle. Possibilities examined across this spectrum include thermal noise, ambient RF scavenging (briefly), thermoelectricity, piezoelectricity, pyroelectricity, and electrochemistry, especially including electrochemistry facilitated by microorganisms.

Date Published: 21 October 2016
PDF: 11 pages
Proc. SPIE 9986, Unmanned/Unattended Sensors and Sensor Networks XII, 99860A (21 October 2016); doi: 10.1117/12.2246707

Published in SPIE Proceedings Vol. 9986:
Unmanned/Unattended Sensors and Sensor Networks XII
Edward M. Carapezza; Panos G. Datskos; Christos Tsamis, Editor(s)