An energy harvesting system surveyed for a variety of unattended electronic applications

0038-1101/$ see front matter 2012 Elsevier Ltd. A http://dx.doi.org/10.1016/j.sse.2012.09.008 ⇑ Corresponding author. Tel.: +1 301 405 3735. E-mail address: [email protected] (W. Zhao). All energy-harvesting schemes require some form of ‘‘intermediate’’ storage – batteries or capacitors that reservoir energy harvested from the environment. There are a number of reasons for this requirement. Ambient energy fluctuates and intermediate storage smoothes out the impact of these fluctuations on the power delivered to a load. In addition, energy must be ‘‘conditioned’’ to be useful in a given application. It must be set to a certain voltage or made capable of delivering a desired current to load. In this article, a complete energy harvesting system including storage and conditioning electronics is described with a concentration on radio frequency (RF) harvesting. The system is capable of harvesting energy from a commercially available hand-held communication device, and exhibits an overall energy harvesting efficiency of 13.2%. Several potential applications have been investigated based on the performance of this system. Highlighted example applications include power sources for nodes in an architectural structural integrity monitor, and limb prosthesis. 2012 Elsevier Ltd. All rights reserved.