ENZYME: An Energy-Efficient Transient Computing Paradigm for Ultralow Self-Powered IoT Edge Devices

Abstract

Internet of Things (IoT) edge devices usually work under power-constrained scenarios like outdoor environmental monitoring. Considering the cost and sustainability in a long run, energy harvesting technology is preferable for edge devices. Nevertheless, the harvesting power is generally weak and unstable, making it difficult for edge devices to maintain the normal functionality. Hence, it is crucial to improve the energy efficiency of edge devices. This paper proposes a software paradigm, ENZYME, to improve the energy efficiency of edge devices for transient computing with ultralow energy harvesting power supplies. ENZYME consists of two lightweight yet highly efficient software modules including Routine Handler and frequency modulator (FM). Routine Handler assists power regulator to maximize power extraction from energy harvesters with proper operation routines. Further, FM maximizes the utility of the extracted energy for program execution via efficient runtime clock frequency modulation. The lightweight and highly efficient natures enable ENZYME to be integrated into low-power IoT edge devices easily and efficiently. Experimental results demonstrate that ENZYME achieves more than 8.8% energy efficiency over state-of-the-art techniques with Routine Handler, and 35.71% extra energy utility with FM upon applying Routine Handler.