Approaches to energy harvesting and energy scavenging for energy autonomous sensors and microinstruments

In chemical analysis, there are numerous applications requiring results in (near) real-time and measurement on-site. In many remote or not-easily-accessible locations, measuring analytical systems (e.g., sensors, microinstruments) require energy autonomy for unattended operation over prolonged periods of time. In this paper, energy harvesting and energy scavenging approaches that may be used for this purpose are critically evaluated and two examples of current research are briefly described. One involves energy harvested from a water-stream (by taking advantage of the electrochemical potential difference between the soil adjacent to the stream and the surface water of the stream) and the other, using a self-powering detector of visible light developed on a flexible polymeric substrate