System design principles combining sub-threshold circuit and architectures with energy scavenging mechanisms

Ultra low power (ULP) circuits and energy scavenging mechanisms, though conceptually appealing, have been mainly studied in isolation to date. In this paper, we observe energy harvesting prototypes to derive system-level models and to reveal practical issues specific to various types of energy harvesting systems. Our models predict how design decisions affect overall lifetime. We use our model to derive system driven principles for optimizing architecture, voltage selection, and sub-threshold circuit designs across different types of power harvesting systems.